TY - GEN
A1 - Sandau, Ingo
A1 - Granacher, Urs
T1 - Effects of the barbell load on the acceleration phase during the snatch in Olympic weightlifting
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - The load-depended loss of vertical barbell velocity at the end of the acceleration phase limits the maximum weight that can be lifted. Thus, the purpose of this study was to analyze how increased barbell loads affect the vertical barbell velocity in the sub-phases of the acceleration phase during the snatch. It was hypothesized that the load-dependent velocity loss at the end of the acceleration phase is primarily associated with a velocity loss during the 1st pull. For this purpose, 14 male elite weightlifters lifted seven load-stages from 70–100% of their personal best in the snatch. The load–velocity relationship was calculated using linear regression analysis to determine the velocity loss at 1st pull, transition, and 2nd pull. A group mean data contrast analysis revealed the highest load-dependent velocity loss for the 1st pull (t = 1.85, p = 0.044, g = 0.49 [−0.05, 1.04]) which confirmed our study hypothesis. In contrast to the group mean data, the individual athlete showed a unique response to increased loads during the acceleration sub-phases of the snatch. With the proposed method, individualized training recommendations on exercise selection and loading schemes can be derived to specifically improve the sub-phases of the snatch acceleration phase. Furthermore, the results highlight the importance of single-subject assessment when working with elite athletes in Olympic weightlifting.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 681
KW - biomechanics
KW - barbell velocity
KW - performance
KW - training
KW - load–velocity relationship
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-471599
SN - 1866-8364
IS - 681
ER -
TY - JOUR
A1 - Sandau, Ingo
A1 - Granacher, Urs
T1 - Effects of the barbell load on the acceleration phase during the snatch in elite Olympic weightlifting
JF - Sports
N2 - The load-depended loss of vertical barbell velocity at the end of the acceleration phase limits the maximum weight that can be lifted. Thus, the purpose of this study was to analyze how increased barbell loads affect the vertical barbell velocity in the sub-phases of the acceleration phase during the snatch. It was hypothesized that the load-dependent velocity loss at the end of the acceleration phase is primarily associated with a velocity loss during the 1st pull. For this purpose, 14 male elite weightlifters lifted seven load-stages from 70-100% of their personal best in the snatch. The load-velocity relationship was calculated using linear regression analysis to determine the velocity loss at 1st pull, transition, and 2nd pull. A group mean data contrast analysis revealed the highest load-dependent velocity loss for the 1st pull (t = 1.85, p = 0.044, g = 0.49 [-0.05, 1.04]) which confirmed our study hypothesis. In contrast to the group mean data, the individual athlete showed a unique response to increased loads during the acceleration sub-phases of the snatch. With the proposed method, individualized training recommendations on exercise selection and loading schemes can be derived to specifically improve the sub-phases of the snatch acceleration phase. Furthermore, the results highlight the importance of single-subject assessment when working with elite athletes in Olympic weightlifting.
KW - biomechanics
KW - barbell velocity
KW - performance
KW - training
KW - load-velocity
KW - relationship
Y1 - 2020
U6 - https://doi.org/10.3390/sports8050059
SN - 2075-4663
VL - 8
IS - 5
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Sammoud, Senda
A1 - Negra, Yassine
A1 - Bouguezzi, Raja
A1 - Hachana, Younes
A1 - Granacher, Urs
A1 - Chaabene, Helmi
T1 - The effects of plyometric jump training on jump and sport-specific performances in prepubertal female swimmers
JF - Journal of exercise science and fitness : JESF : official journal of The Society of Chinese Scholars on Exercise Physiology and Fitness and Hong Kong Association of Sports Medicine & Sports Science
N2 - Background/objective
Dry land-training (e.g., plyometric jump training) can be a useful mean to improve swimming performance. This study examined the effects of an 8-week plyometric jump training (PJT) program on jump and sport-specific performances in prepubertal female swimmers.
Methods
Twenty-two girls were randomly assigned to either a plyometric jump training group (PJTG; n = 12, age: 10.01 ± 0.57 years, maturity-offset = -1.50 ± 0.50, body mass = 36.39 ± 6.32 kg, body height = 146.90 ± 7.62 cm, body mass index = 16.50 ± 1.73 kg/m2) or an active control (CG; n = 10, age: 10.50 ± 0.28 years, maturity-offset = -1.34 ± 0.51, body mass = 38.41 ± 9.42 kg, body height = 143.60 ± 5.05 cm, body mass index = 18.48 ± 3.77 kg/m2). Pre- and post-training, tests were conducted for the assessment of muscle power (e.g., countermovement-jump [CMJ], standing-long-jump [SLJ]). Sport-specific-performances were tested using the timed 25 and 50-m front crawl with a diving-start, timed 25-m front crawl without push-off from the wall (25-m WP), and a timed 25-m kick without push-off from the wall (25-m KWP).
Results
Findings showed a significant main effect of time for the CMJ (d = 0.78), the SLJ (d = 0.91), 25-m front crawl test (d = 2.5), and the 25-m-KWP (d = 1.38) test. Significant group × time interactions were found for CMJ, SLJ, 25-m front crawl, 50-m front crawl, 25-m KWP, and 25-m WP test (d = 0.29–1.63) in favor of PJTG (d = 1.34–3.50). No significant pre-post changes were found for CG (p > 0.05).
Conclusion
In sum, PJT is effective in improving muscle power and sport-specific performances in prepubertal swimmers. Therefore, PJT should be included from an early start into the regular training program of swimmers.
KW - Stretch-shortening cycle
KW - Young swimmers
KW - Swimming performance
Y1 - 2020
U6 - https://doi.org/10.1016/j.jesf.2020.07.003
SN - 1728-869x
VL - 19
IS - 1
SP - 25
EP - 31
PB - Elsevier
CY - Singapore
ER -
TY - GEN
A1 - Sammoud, Senda
A1 - Negra, Yassine
A1 - Bouguezzi, Raja
A1 - Hachana, Younes
A1 - Granacher, Urs
A1 - Chaabene, Helmi
T1 - The effects of plyometric jump training on jump and sport-specific performances in prepubertal female swimmers
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Background/objective
Dry land-training (e.g., plyometric jump training) can be a useful mean to improve swimming performance. This study examined the effects of an 8-week plyometric jump training (PJT) program on jump and sport-specific performances in prepubertal female swimmers.
Methods
Twenty-two girls were randomly assigned to either a plyometric jump training group (PJTG; n = 12, age: 10.01 ± 0.57 years, maturity-offset = -1.50 ± 0.50, body mass = 36.39 ± 6.32 kg, body height = 146.90 ± 7.62 cm, body mass index = 16.50 ± 1.73 kg/m2) or an active control (CG; n = 10, age: 10.50 ± 0.28 years, maturity-offset = -1.34 ± 0.51, body mass = 38.41 ± 9.42 kg, body height = 143.60 ± 5.05 cm, body mass index = 18.48 ± 3.77 kg/m2). Pre- and post-training, tests were conducted for the assessment of muscle power (e.g., countermovement-jump [CMJ], standing-long-jump [SLJ]). Sport-specific-performances were tested using the timed 25 and 50-m front crawl with a diving-start, timed 25-m front crawl without push-off from the wall (25-m WP), and a timed 25-m kick without push-off from the wall (25-m KWP).
Results
Findings showed a significant main effect of time for the CMJ (d = 0.78), the SLJ (d = 0.91), 25-m front crawl test (d = 2.5), and the 25-m-KWP (d = 1.38) test. Significant group × time interactions were found for CMJ, SLJ, 25-m front crawl, 50-m front crawl, 25-m KWP, and 25-m WP test (d = 0.29–1.63) in favor of PJTG (d = 1.34–3.50). No significant pre-post changes were found for CG (p > 0.05).
Conclusion
In sum, PJT is effective in improving muscle power and sport-specific performances in prepubertal swimmers. Therefore, PJT should be included from an early start into the regular training program of swimmers.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 658
KW - Stretch-shortening cycle
KW - Young swimmers
KW - Swimming performance
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-478272
SN - 1866-8364
IS - 658
ER -
TY - GEN
A1 - Sallen, Jeffrey
A1 - Hemming, Karen
A1 - Richartz, Alfred
T1 - Facilitating dual careers by improving resistance to chronic stress
BT - effects of an intervention programme for elite student athletes
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - The starting point of this contribution is the potential risk to health and performance from the combination of elite sporting careers with the pursuit of education. In European sport science and politics, structural measures to promote dual careers in elite sports have been discussed increasingly of late. In addition to organisational measures, there are calls for educational-psychological intervention programmes supporting the successful management of dual careers at the individual level. This paper presents an appropriate intervention programme and its evaluation: stress-resistance training for elite athletes (SRT-EA). It comprises 10 units, each lasting 90 minutes. It is intended for athletes and aims to improve their resistance to chronic stress. The evaluation was carried out in a quasi-experimental design, with three points of measurement (baseline, immediately after, and three months after) and two non-randomised groups: an intervention group (n = 128) and an untreated control group (n = 117). Participants were between 13 and 20 years of age (53.5% male) and represented
various Olympic sports. Outcome variables were assessed with questionnaires. Significant short- and mid-term intervention effects were explored. The intervention increased stress-related knowledge, general self-efficacy, and stress sensitivity. Chronic stress level, stress symptoms, and stress reactivity were reduced. In line with the intention of the intervention, the results showed short- and mid-term, small to medium-sized effects. Accordingly, separate measurements at the end of the intervention and three months later showed mostly positive subjective experiences. Thus, the results reinforce the hope that educational-psychological stress-management interventions can support dual careers.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 463
KW - chronic stress
KW - stress-resistance
KW - elite athletes
KW - intervention
KW - evaluation
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-412735
IS - 463
ER -
TY - JOUR
A1 - Sallen, Jeffrey
A1 - Andrä, Christian
A1 - Ludyga, Sebastian
A1 - Mücke, Manuel
A1 - Herrmann, Christian
T1 - School children's physical activity, motor competence, and corresponding self-perception
BT - a longitudinal analysis of reciprocal relationships
JF - Journal of physical activity and health
N2 - Background: The relationship between engagement in physical activity and the development of motor competence (MC) is considered to be reciprocal and dynamic throughout childhood and adolescence. The 10-month follow-up study aimed to explore this reciprocal relationship and investigated whether the relationship is mediated by the corresponding self-perception of MC (PMC).
Methods: A total of 51 children aged between 10 and 11 years (M = 10.27 [0.45]) participated in the study (52.9% boys, 47.1% girls). As an indicator for physical activity, the average vigorous physical activity (VPA) per day was measured by ActiGraph accelerometers. Two aspects of MC and PMC were recorded: self-movement and object movement. Saturated pathway models in a cross-lagged panel design with 2 measurement points were analyzed.
Results: Reciprocal and direct relationships between VPA and MC object movement respectively MC self-movement were not found in longitudinal analyses with PMC as a mediator. Indirect effects of MC at t1 on VPA at t2 via PMC were identified (self-movement: beta = 0.13, 95% confidence interval, 0.04 to 0.26; object movement: beta = 0.14, 95% confidence interval, 0.01 to 0.49).
Conclusion: The results highlight the importance of MC and PMC in promoting children's VPA. However, VPA does not drive the development of MC.
KW - MOBAK
KW - SEMOK
KW - fundamental movement skills
KW - motor proficiency
Y1 - 2020
U6 - https://doi.org/10.1123/jpah.2019-0507
SN - 1543-3080
SN - 1543-5474
VL - 17
IS - 11
SP - 1083
EP - 1090
PB - Human Kinetics Publ.
CY - Champaign
ER -
TY - JOUR
A1 - Saidi, Karim
A1 - Zouhal, Hassane
A1 - Boullosa, Daniel
A1 - Dupont, Gregory
A1 - Hackney, Anthony C.
A1 - Bideau, Benoit
A1 - Granacher, Urs
A1 - Ben Abderrahman, Abderraouf
T1 - Biochemical markers and wellness status during a congested match play period in elite soccer players
JF - International journal of sports physiology and performance : IJSSP
N2 - Objectives:
To analyze biochemical markers, wellness status, and physical fitness in elite soccer players in relation to changes in training and match exposure during a congested period of match play.
Methods:
Fourteen elite soccer players were evaluated 3 times (T1, T2, and T3) over 12 weeks (T1-T2: 6-wk regular period of match play and T2-T3: 6-wk congested period of match play). Players performed vertical jump tests, repeated shuttle sprint ability test, and the Yo-Yo Intermittent Recovery Test at T1, T2, and T3. Plasma C-reactive protein, creatinine, and creatine kinase were analyzed at T1, T2, and T3. Wellness status was measured daily using the Hopper questionnaire (delayed onset of muscle soreness, stress, fatigue, and sleep quality). Training session rating of perceived exertion was also recorded on a daily basis.
Results:
A significant increase was found in stress, fatigue, delayed onset of muscle soreness scores, and Hopper index during the congested period (between T2 and T3) compared with the regular period (between T1 and T2) (.001 < P < .008, 0.8 < ES < 2.3). Between T2 and T3, significant relationships were found between the percentage variations (Delta%) of C-reactive protein, and Delta% of creatine kinase with the Hopper Index, and the Delta% of fatigue score. In addition, the Delta% of fatigue score and Delta% of delayed onset of muscle soreness score correlated with Delta% Yo-Yo Intermittent Recovery Test and Delta% best of repeated shuttle sprint ability test (.49 < r < P < .01).
Conclusions:
An intensive period of congested match play significantly compromised elite soccer players' physical fitness and wellness status. Elite soccer players' wellness status reflects declines in physical fitness during this period while biochemical changes do not.
KW - training
KW - congested calendar
KW - overtraining
KW - overreaching
KW - recovery
Y1 - 2022
U6 - https://doi.org/10.1123/ijspp.2020-0914
SN - 1555-0265
SN - 1555-0273
VL - 17
IS - 4
SP - 605
EP - 620
PB - Human Kinetics Publ.
CY - Champaign
ER -
TY - JOUR
A1 - Saal, Christian
A1 - Chaabene, Helmi
A1 - Helm, Norman
A1 - Warnke, Torsten
A1 - Prieske, Olaf
T1 - Network analysis of associations between anthropometry, physical fitness, and sport-specific performance in young canoe sprint athletes
BT - The role of age and sex
JF - Frontiers in sports and active living
N2 - Introduction
Anthropometric and physical fitness data can predict sport-specific performance (e.g., canoe sprint race time) in young athletes. Of note, inter-item correlations (i.e., multicollinearity) may exist between tests assessing similar physical qualities. However, multicollinearity among tests may change across age and/or sex due to age-/sex-specific non-linear development of test performances. Therefore, the present study aimed at analyzing inter-item correlations between anthropometric, physical fitness, and sport-specific performance data as a function of age and sex in young canoe sprint athletes.
Methods
Anthropometric, physical fitness, and sport-specific performance data of 618 male and 297 female young canoe sprint athletes (discipline: male/female kayak, male canoe) were recorded during a national talent identification program between 1992 and 2019. For each discipline, a correlation matrix (i.e., network analysis) was calculated for age category (U13, U14, U15, U16) and sex including anthropometrics (e.g., standing body height, body mass), physical fitness (e.g., cardiorespiratory endurance, muscle power), and sport-specific performance (i.e., 250 and 2,000-m on-water canoe sprint time). Network plots were used to explore the correlation patterns by visual inspection. Further, trimmed means (mu(trimmed)) of inter-item Pearson's correlations coefficients were calculated for each discipline, age category, and sex. Effects of age and sex were analyzed using one-way ANOVAs.
Results
Visual inspection revealed consistent associations among anthropometric measures across age categories, irrespective of sex. Further, associations between physical fitness and sport-specific performance were lower with increasing age, particularly in males. In this sense, statistically significant differences for mu(trimmed) were observed in male canoeists (p < 0.01, xi = 0.36) and male kayakers (p < 0.01, xi = 0.38) with lower mu(trimmed) in older compared with younger athletes (i.e., >= U15). For female kayakers, no statistically significant effect of age on mu(trimmed) was observed (p = 0.34, xi = 0.14).
Discussion
Our study revealed that inter-item correlation patterns (i.e., multicollinearity) of anthropometric, physical fitness, and sport-specific performance measures were lower in older (U15, U16) versus younger (U13, U14) male canoe sprint athletes but not in females. Thus, age and sex should be considered to identify predictors for sport-specific performance and design effective testing batteries for talent identification programs in canoe sprint athletes.
KW - talent identification
KW - youth sports [MeSH]
KW - athletic performance
KW - race
KW - time
KW - relationship
KW - multicollinearity
Y1 - 2022
U6 - https://doi.org/10.3389/fspor.2022.1038350
SN - 2624-9367
VL - 4
PB - Frontiers Media
CY - Lausanne
ER -
TY - GEN
A1 - Ramirez-Campillo, Rodrigo
A1 - Moran, Jason
A1 - Oliver, Jonathan L.
A1 - Pedley, Jason S.
A1 - Lloyd, Rhodri S.
A1 - Granacher, Urs
T1 - Programming Plyometric-Jump Training in Soccer: A Review
T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - The aim of this review was to describe and summarize the scientific literature on programming parameters related to jump or plyometric training in male and female soccer players of different ages and fitness levels. A literature search was conducted in the electronic databases PubMed, Web of Science and Scopus using keywords related to the main topic of this study (e.g., “ballistic” and “plyometric”). According to the PICOS framework, the population for the review was restricted to soccer players, involved in jump or plyometric training. Among 7556 identified studies, 90 were eligible for inclusion. Only 12 studies were found for females. Most studies (n = 52) were conducted with youth male players. Moreover, only 35 studies determined the effectiveness of a given jump training programming factor. Based on the limited available research, it seems that a dose of 7 weeks (1–2 sessions per week), with ~80 jumps (specific of combined types) per session, using near-maximal or maximal intensity, with adequate recovery between repetitions (<15 s), sets (≥30 s) and sessions (≥24–48 h), using progressive overload and taper strategies, using appropriate surfaces (e.g., grass), and applied in a well-rested state, when combined with other training methods, would increase the outcome of effective and safe plyometric-jump training interventions aimed at improving soccer players physical fitness. In conclusion, jump training is an effective and easy-to-administer training approach for youth, adult, male and female soccer players. However, optimal programming for plyometric-jump training in soccer is yet to be determined in future research.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 813
KW - human physical conditioning
KW - exercise
KW - resistance training
KW - muscle strength
KW - plyometric exercise
KW - musculoskeletal and neural physiological phenomena
KW - movement
KW - sports
KW - football
KW - youth sport
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-581031
SN - 1866-8364
IS - 813
ER -
TY - JOUR
A1 - Ramirez-Campillo, Rodrigo
A1 - Moran, Jason
A1 - Oliver, Jonathan L.
A1 - Pedley, Jason S.
A1 - Lloyd, Rhodri S.
A1 - Granacher, Urs
T1 - Programming Plyometric-Jump Training in Soccer: A Review
JF - Sports
N2 - The aim of this review was to describe and summarize the scientific literature on programming parameters related to jump or plyometric training in male and female soccer players of different ages and fitness levels. A literature search was conducted in the electronic databases PubMed, Web of Science and Scopus using keywords related to the main topic of this study (e.g., “ballistic” and “plyometric”). According to the PICOS framework, the population for the review was restricted to soccer players, involved in jump or plyometric training. Among 7556 identified studies, 90 were eligible for inclusion. Only 12 studies were found for females. Most studies (n = 52) were conducted with youth male players. Moreover, only 35 studies determined the effectiveness of a given jump training programming factor. Based on the limited available research, it seems that a dose of 7 weeks (1–2 sessions per week), with ~80 jumps (specific of combined types) per session, using near-maximal or maximal intensity, with adequate recovery between repetitions (<15 s), sets (≥30 s) and sessions (≥24–48 h), using progressive overload and taper strategies, using appropriate surfaces (e.g., grass), and applied in a well-rested state, when combined with other training methods, would increase the outcome of effective and safe plyometric-jump training interventions aimed at improving soccer players physical fitness. In conclusion, jump training is an effective and easy-to-administer training approach for youth, adult, male and female soccer players. However, optimal programming for plyometric-jump training in soccer is yet to be determined in future research.
KW - human physical conditioning
KW - exercise
KW - resistance training
KW - muscle strength
KW - plyometric exercise
KW - musculoskeletal and neural physiological phenomena
KW - movement
KW - sports
KW - football
KW - youth sport
Y1 - 2022
U6 - https://doi.org/10.3390/sports10060094
SN - 2075-4663
VL - 10
SP - 1
EP - 20
PB - MDPI
CY - Basel, Schweiz
ET - 6
ER -
TY - GEN
A1 - Quarmby, Andrew James
A1 - Mönnig, Jamal
A1 - Mugele, Hendrik
A1 - Henschke, Jakob
A1 - Kim, MyoungHwee
A1 - Cassel, Michael
A1 - Engel, Tilman
T1 - Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review
T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of “medial collapse”. Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 830
KW - achilles tendinopathy
KW - biomechanics
KW - neuromuscular
KW - kinetics
KW - electromyography
KW - athletes
KW - runners
KW - kinematics
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587603
SN - 1866-8364
IS - 830
ER -
TY - JOUR
A1 - Quarmby, Andrew James
A1 - Mönnig, Jamal
A1 - Mugele, Hendrik
A1 - Henschke, Jakob
A1 - Kim, MyoungHwee
A1 - Cassel, Michael
A1 - Engel, Tilman
T1 - Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review
JF - Frontiers in Sports and Active Living
N2 - Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of “medial collapse”. Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn.
KW - achilles tendinopathy
KW - biomechanics
KW - neuromuscular
KW - kinetics
KW - electromyography
KW - athletes
KW - runners
KW - kinematics
Y1 - 2023
U6 - https://doi.org/10.3389/fspor.2022.1012471
SN - 2624-9367
PB - Frontiers
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Quarmby, Andrew James
A1 - Khajooei, Mina
A1 - Engel, Tilman
A1 - Kaplick, Hannes
A1 - Mayer, Frank
T1 - The feasibility of a split-belt instrumented treadmill running protocol with perturbations
JF - Journal of biomechanics
N2 - Unexpected perturbations during locomotion can occur during daily life or sports performance. Adequate compensation for such perturbations is crucial in maintaining effective postural control. Studies utilising instrumented treadmills have previously validated perturbed walking protocols, however responses to perturbed running protocols remain less investigated. Therefore, the purpose of this study was to investigate the feasibility of a new instrumented treadmill-perturbed running protocol.
Fifteen participants (age = 2 8 +/- 3 years; height = 172 +/- 9 cm; weight = 69 +/- 10 kg; 60% female) completed an 8-minute running protocol at baseline velocity of 2.5 m/s (9 km/h), whilst 15 one-sided belt perturbations were applied (pre-set perturbation characteristics: 150 ms delay (post-heel contact); 2.0 m/s amplitude; 100 ms duration). Perturbation characteristics and EMG responses were recorded. Bland-Altman analysis (BLA) was employed (bias +/- limits of agreement (LOA; bias +/- 1.96*SD)) and intra-individual variability of repeated perturbations was assessed via Coefficients of Variation (CV) (mean +/- SD).
On average, 9.4 +/- 2.2 of 15 intended perturbations were successful. Perturbation delay was 143 +/- 10 ms, amplitude was 1.7 +/- 0.2 m/s and duration was 69 +/- 10 ms. BLA showed -7 +/- 13 ms for delay, -0.3 +/- 0.1 m/s for amplitude and -30 +/- 10 ms for duration. CV showed variability of 19 +/- 4.5% for delay, 58 +/- 12% for amplitude and 30 +/- 7% for duration. EMG RMS amplitudes of the legs and trunk ranged from 113 +/- 25% to 332 +/- 305% when compared to unperturbed gait. This study showed that the application of sudden perturbations during running can be achieved, though with increased variability across individuals. The perturbations with the above characteristics appear to have elicited a neuromuscular response during running.
KW - Lower-extremity perturbations
KW - Split-belt treadmill
KW - Running
KW - Stumbling
KW - EMC
Y1 - 2020
U6 - https://doi.org/10.1016/j.jbiomech.2019.109493
SN - 0021-9290
SN - 1873-2380
VL - 98
PB - Elsevier
CY - Oxford
ER -
TY - GEN
A1 - Puschmann, Anne-Katrin
A1 - Lin, I-Chiao
A1 - Wippert, Pia-Maria
T1 - Sustainability of a motor control exercise intervention
BT - Analysis of long-term effects in a low back pain study
T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Development of chronic pain after a low back pain episode is associated with increased pain sensitivity, altered pain processing mechanisms and the influence of psychosocial factors. Although there is some evidence that multimodal therapy (such as behavioral or motor control therapy) may be an important therapeutic strategy, its long-term effect on pain reduction and psychosocial load is still unclear. Prospective longitudinal designs providing information about the extent of such possible long-term effects are missing. This study aims to investigate the long-term effects of a homebased uni- and multidisciplinary motor control exercise program on low back pain intensity, disability and psychosocial variables. 14 months after completion of a multicenter study comparing uni- and multidisciplinary exercise interventions, a sample of one study center (n = 154) was assessed once more. Participants filled in questionnaires regarding their low back pain symptoms (characteristic pain intensity and related disability), stress and vital exhaustion (short version of the Maastricht Vital Exhaustion Questionnaire), anxiety and depression experiences (the Hospital and Anxiety Depression Scale), and pain-related cognitions (the Fear Avoidance Beliefs Questionnaire). Repeated measures mixed ANCOVAs were calculated to determine the long-term effects of the interventions on characteristic pain intensity and disability as well as on the psychosocial variables. Fifty four percent of the sub-sample responded to the questionnaires (n = 84). Longitudinal analyses revealed a significant long-term effect of the exercise intervention on pain disability. The multidisciplinary group missed statistical significance yet showed a medium sized long-term effect. The groups did not differ in their changes of the psychosocial variables of interest. There was evidence of long-term effects of the interventions on pain-related disability, but there was no effect on the other variables of interest. This may be partially explained by participant's low comorbidities at baseline. Results are important regarding costless homebased alternatives for back pain patients and prevention tasks. Furthermore, this study closes the gap of missing long-term effect analysis in this field.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 752
KW - MiSpEx
KW - low back pain
KW - long-term effects
KW - multidisciplinary intervention
KW - sustainability
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544083
SN - 1866-8364
SP - 1
EP - 8
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Puschmann, Anne-Katrin
A1 - Lin, Chiao-I
A1 - Wippert, Pia-Maria
T1 - Sustainability of a motor control exercise intervention
BT - Analysis of long-term effects in a low back pain study
JF - Frontiers in sports and active living
N2 - Development of chronic pain after a low back pain episode is associated with increased pain sensitivity, altered pain processing mechanisms and the influence of psychosocial factors. Although there is some evidence that multimodal therapy (such as behavioral or motor control therapy) may be an important therapeutic strategy, its long-term effect on pain reduction and psychosocial load is still unclear. Prospective longitudinal designs providing information about the extent of such possible long-term effects are missing. This study aims to investigate the long-term effects of a homebased uni- and multidisciplinary motor control exercise program on low back pain intensity, disability and psychosocial variables. 14 months after completion of a multicenter study comparing uni- and multidisciplinary exercise interventions, a sample of one study center (n = 154) was assessed once more. Participants filled in questionnaires regarding their low back pain symptoms (characteristic pain intensity and related disability), stress and vital exhaustion (short version of the Maastricht Vital Exhaustion Questionnaire), anxiety and depression experiences (the Hospital and Anxiety Depression Scale), and pain-related cognitions (the Fear Avoidance Beliefs Questionnaire). Repeated measures mixed ANCOVAs were calculated to determine the long-term effects of the interventions on characteristic pain intensity and disability as well as on the psychosocial variables. Fifty four percent of the sub-sample responded to the questionnaires (n = 84). Longitudinal analyses revealed a significant long-term effect of the exercise intervention on pain disability. The multidisciplinary group missed statistical significance yet showed a medium sized long-term effect. The groups did not differ in their changes of the psychosocial variables of interest. There was evidence of long-term effects of the interventions on pain-related disability, but there was no effect on the other variables of interest. This may be partially explained by participant's low comorbidities at baseline. Results are important regarding costless homebased alternatives for back pain patients and prevention tasks. Furthermore, this study closes the gap of missing long-term effect analysis in this field.
KW - MiSpEx
KW - low back pain
KW - long-term effects
KW - multidisciplinary intervention
KW - sustainability
Y1 - 2021
U6 - https://doi.org/10.3389/fspor.2021.659982
SN - 2624-9367
VL - 3
SP - 1
EP - 8
PB - Frontiers Media
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Prieske, Olaf
A1 - Chaabene, Helmi
A1 - Puta, Christian
A1 - Behm, David George
A1 - Büsch, Dirk
A1 - Granacher, Urs
T1 - Effects of Drop Height on Jump Performance in Male and Female Elite Adolescent Handball Players
JF - International journal of sports physiology and performance
N2 - Purpose: To examine the effects of drop height on drop-jump (DJ) performance and on associations between DJ and horizontal-jump/sprint performances in adolescent athletes. Methods: Male (n = 119, 2.5 [0.6] y post-peak-height velocity) and female (n = 120, 2.5 [0.5] y post-peak-height velocity) adolescent handball players (national level) performed DJs in randomized order using 3 drop heights (20, 35, and 50 cm). DJ performance (jump height, reactive strength index [RSI]) was analyzed using the Optojump Next system. In addition, correlations were computed between DJ height and RSI with standing-long-jump and 20-m linear-sprint performances. Results: Statistical analyses revealed medium-size main effects of drop height for DJ height and RSI (P <.001, 0.63 <= d <= 0.71). Post hoc tests indicated larger DJ heights from 20 to 35 and 35 to 50 cm (P <=.031, 0.33 <= d <= 0.71) and better RSI from 20- to 35-cm drop height (P <.001, d = 0.77). No significant difference was found for RSI between 35- and 50-cm drop height. Irrespective of drop height, associations of DJ height and RSI were small with 5-m-split time (-.27 <= r <=.05), medium with 10-m-split time (-.44 <= r <=.14), and medium to large with 20-m sprint time and standing-long-jump distance (-.57 <= r <=.22). Conclusions: The present findings indicate that, irrespective of sex, 35-cm drop heights are best suited to induce rapid and powerful DJ performance (ie, RSI) during reactive strength training in elite adolescent handball players. Moreover, training-related gains in DJ performance may at least partly translate to gains in horizontal jump and longer sprint distances (ie, >= 20-m) and/or vice versa in male and female elite adolescent athletes, irrespective of drop height.
KW - stretch-shortening cycle
KW - plyometric training
KW - strength training
KW - tendon stiffness
KW - young athletes
Y1 - 2019
U6 - https://doi.org/10.1123/ijspp.2018-0482
SN - 1555-0265
SN - 1555-0273
VL - 14
IS - 5
SP - 674
EP - 680
PB - Human Kinetics Publ.
CY - Champaign
ER -
TY - GEN
A1 - Pavillon, Thomas
A1 - Tourny, Claire
A1 - Ben Abderrahman, Abderraouf
A1 - Salhi, Iyed
A1 - Zouita, Sghaeir
A1 - Rouissi, Mehdi
A1 - Hackney, Anthony C.
A1 - Granacher, Urs
A1 - Zouhal, Hassane
T1 - Sprint and jump performances in highly trained young soccer players of different chronological age
BT - Effects of linear VS. CHANGE–OF–DIRECTION sprint training
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Objective
The aim of this study was to examine the effects of two different sprint-training regimes on sprint and jump performances according to age in elite young male soccer players over the course of one soccer season.
Methods
Players were randomly assigned to two training groups. Group 1 performed systematic change-of-direction sprints (CODST, U19 [n = 9], U17 [n = 9], U15 [n = 10]) while group 2 conducted systematic linear sprints (LST, U19 [n = 9], U17 [n = 9], U15 [n = 9]). Training volumes were similar between groups (40 sprints per week x 30 weeks = 1200 sprints per season). Pre and post training, all players performed tests for the assessment of linear and slalom sprint speed (5-m and 10-m), countermovement jump, and maximal aerobic speed performance.
Results
For all physical fitness measures, the baseline-adjusted means data (ANCOVA) across the age groups showed no significant differences between LST and CODST at post (0.061 < p < 0.995; 0.0017 < d < 1.01). The analyses of baseline-adjusted means for all physical fitness measures for U15, U17, and U19 (LST vs. CODST) revealed no significant differences between LST and CODST for U15 (0.213 < p < 0.917; 0.001 < d < 0.087), U17 (0.132 < p < 0.976; 0.001 < d < 0.310), and U19 (0.300 < p < 0.999; 0.001 < d < 0.049) at post.
Conclusions
The results from this study showed that both, LST and CODST induced significant changes in the sprint, lower limbs power, and aerobic performances in young elite soccer players. Since no significant differences were observed between LST and CODST, the observed changes are most likely due to training and/or maturation. Therefore, more research is needed to elucidate whether CODST, LST or a combination of both is beneficial for youth soccer athletes’ performance development.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 697
KW - Football
KW - Repeated sprint
KW - Performance
KW - Speed
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-490557
SN - 1866-8364
IS - 697
ER -
TY - JOUR
A1 - Pavillon, Thomas
A1 - Tourny, Claire
A1 - Ben Abderrahman, Abderraouf
A1 - Salhi, Iyed
A1 - Zouita, Sghaeir
A1 - Rouissi, Mehdi
A1 - Hackney, Anthony C.
A1 - Granacher, Urs
A1 - Zouhal, Hassane
T1 - Sprint and jump performances in highly trained young soccer players of different chronological age
BT - Effects of linear VS. CHANGE–OF–DIRECTION sprint training
JF - Journal of Exercise Science & Fitness
N2 - Objective
The aim of this study was to examine the effects of two different sprint-training regimes on sprint and jump performances according to age in elite young male soccer players over the course of one soccer season.
Methods
Players were randomly assigned to two training groups. Group 1 performed systematic change-of-direction sprints (CODST, U19 [n = 9], U17 [n = 9], U15 [n = 10]) while group 2 conducted systematic linear sprints (LST, U19 [n = 9], U17 [n = 9], U15 [n = 9]). Training volumes were similar between groups (40 sprints per week x 30 weeks = 1200 sprints per season). Pre and post training, all players performed tests for the assessment of linear and slalom sprint speed (5-m and 10-m), countermovement jump, and maximal aerobic speed performance.
Results
For all physical fitness measures, the baseline-adjusted means data (ANCOVA) across the age groups showed no significant differences between LST and CODST at post (0.061 < p < 0.995; 0.0017 < d < 1.01). The analyses of baseline-adjusted means for all physical fitness measures for U15, U17, and U19 (LST vs. CODST) revealed no significant differences between LST and CODST for U15 (0.213 < p < 0.917; 0.001 < d < 0.087), U17 (0.132 < p < 0.976; 0.001 < d < 0.310), and U19 (0.300 < p < 0.999; 0.001 < d < 0.049) at post.
Conclusions
The results from this study showed that both, LST and CODST induced significant changes in the sprint, lower limbs power, and aerobic performances in young elite soccer players. Since no significant differences were observed between LST and CODST, the observed changes are most likely due to training and/or maturation. Therefore, more research is needed to elucidate whether CODST, LST or a combination of both is beneficial for youth soccer athletes’ performance development.
KW - Football
KW - Repeated sprint
KW - Performance
KW - Speed
Y1 - 2020
U6 - https://doi.org/10.1016/j.jesf.2020.10.003
SN - 1728-869x
VL - 19
IS - 2
SP - 81
EP - 90
PB - Elsevier
CY - Singapore
ER -
TY - JOUR
A1 - Palma-Muñoz, Ignacio
A1 - Ramírez-Campillo, Rodrigo
A1 - Azocar-Gallardo, Jairo
A1 - Álvarez, Cristian
A1 - Asadi, Abbas
A1 - Moran, Jason
A1 - Chaabene, Helmi
T1 - Effects of progressed and nonprogressed volume-based overload plyometric training on components of physical fitness and body composition variables in youth male basketball players
JF - Journal of strength and conditioning research : the research journal of the NSCA
N2 - This study examined the effect of 6 weeks of progressed and nonprogressed volume-based overload plyometric training (PT) on components of physical fitness and body composition measures in young male basketball players, compared with an active control group. Subjects were randomly assigned to a progressed PT (PPT, n = 7; age = 14.6 +/- 1.1 years), a non-PPT (NPPT, n = 8, age = 13.8 +/- 2.0 years), or a control group (CG, n = 7, age = 14.0 +/- 2.0 years). Before and after training, body composition measures (muscle mass and fat mass), countermovement jump with arms (CMJA) and countermovement jump without arms (CMJ), horizontal bilateral (HCMJ) and unilateral jump with right leg (RJ) and left leg (LJ), 20-cm drop jump (DJ20), sprint speed (10 m sprint), and change of direction speed (CODS [i.e., T-test]) were tested. Significant effects of time were observed for muscle and fat mass, all jump measures, and CODS (all p < 0.01; d = 0.37-0.83). Significant training group x time interactions were observed for all jump measures (all p < 0.05; d = 0.24-0.41). Post hoc analyses revealed significant pre-post performance improvements for the PPT (RJ and LJ: increment 18.6%, d = 0.8 and increment 22.7%, d = 0.9, respectively; HCMJ: increment 16.4%, d = 0.8; CMJ: increment 22.4%, d = 0.7; CMJA: increment 23.3%, d = 0.7; and DJ20: increment 39.7%, d = 1.1) and for the NPPT group (LJ: increment 14.1%, d = 0.4; DJ20: increment 32.9%, d = 0.8) with greater changes after PPT compared with NPPT for all jump measures (all p < 0.05; d = 0.21-0.81). The training efficiency was greater (p < 0.05; d = 0.22) after PPT (0.015% per jump) compared with NPPT (0.0053% per-jump). The PPT induced larger performance improvements on measures of physical fitness as compared to NPPT. Therefore, in-season progressive volume-based overload PT in young male basketball players is recommended.
KW - stretch-shortening cycle
KW - young
KW - team sports
KW - athletic performance
KW - anthropometry
Y1 - 2021
U6 - https://doi.org/10.1519/JSC.0000000000002950
SN - 1064-8011
SN - 1533-4287
VL - 35
IS - 6
SP - 1642
EP - 1649
PB - Lippincott Williams & Wilkins
CY - Philadelphia
ER -
TY - JOUR
A1 - Niehues, Maike
A1 - Gerlach, Erin
A1 - Sallen, Jeffrey
T1 - Measuring dual career motivation among German student-athletes using the Student Athletes’ Motivation Toward Sports and Academics Questionnaire
BT - Challenges and failures of linguistic and cultural adaptations
JF - German journal of exercise and sport research : Sportwissenschaft / Bundesinstitut für Sportwissenschaft, Deutscher Olympischer Sportbund, Deutsche Vereinigung für Sportwissenschaft
N2 - With the 2012 EU guidelines on dual careers (DC), DC research gained increasing awareness in Europe focussing particularly on student-athletes' motivation. The Student Athletes' Motivation toward Sports and Academics Questionnaire (SAMSAQ), arguably the most prominent instrument in this research area, has been used in various cross-cultural studies assessing DC motivation. The present investigation contributes to the cross-cultural discourse aiming to (1) adapt the SAMSAQ for the German context and adolescent secondary school student-athletes, and (2) evaluate the German pre-version. A sample of 208 student-athletes (52.4% females, mean age = 17.4 years, 49.5% at squad level) at three German Elite Sport Schools participated in the study. The investigation was split into two parts. First, the SAMSAQ was adapted to the German context and tested. In the second part, the first pre-version was revised. A series of exploratory factor analyses were applied to verify the factor structure of both German SAMSAQ pre-versions. Eight different factor models based on item removal were compared. Neither model demonstrated good results for the replication of previous findings or a meaningful solution in terms of content. Reasons for the deviations between the original and target SAMSAQ factor structures can be found in the different target groups and the culturally different approaches to career assistant programmes as well as in the theoretical background of the instrument. Since neither model was identified as acceptable, the findings indicate that a new instrument needs to be developed for assessing student-athletes' DC motivation along their pathways in different cross-cultural contexts.
T2 - Messung der Motivation deutscher Schüler-Athleten und -Athletinnen in der dualen Karriere mithilfe des Student Athletes’ Motivation Toward Sports and Academics Questionnaire - Herausforderungen und Scheitern sprachlicher und kultureller Anpassungen
KW - SAMSAQ
KW - Factor-analysis
KW - Expectancy-value
KW - Translation
KW - Cross-culture
KW - Elite sport
Y1 - 2021
U6 - https://doi.org/10.1007/s12662-021-00723-9
SN - 2509-3142
SN - 2509-3150
VL - 51
IS - 3
SP - 378
EP - 383
PB - Springer
CY - Berlin ; Heidelberg
ER -
TY - JOUR
A1 - Negra, Yassine
A1 - Sammoud, Senda
A1 - Uthoff, Aaron
A1 - Moran, Jason
A1 - Ramirez-Campillo, Rodrigo
A1 - Chaabene, Helmi
T1 - The effects of repeated backward running training on measures of physical fitness in youth male soccer players
JF - Journal of sports sciences
N2 - This study explored the effects of an 8-week repeated backward running training (RBRT) programme on measures of physical fitness in youth male soccer players. Youth male soccer players were randomly allocated into a RBRT group (n = 20; 13.95 +/- 0.22y) or a control group (CG; n = 16; 14.86 +/- 0.29y). The CG continued normal soccer training, while the RBRT group replaced some soccer drills with RBRT twice per week. Within-group analysis revealed that RBRT improved all performance variables ( increment -9.99% to 14.50%; effect size [ES] = -1.79 to 1.29; p <= 0.001). Meanwhile, trivial-to-moderate detrimental effects on sprinting and change of direction (CoD) speed ( increment 1.55% to 10.40%; p <= 0.05) were noted in the CG. The number of individuals improving performance above the smallest worthwhile change ranged from 65-100% across all performance variables in the RBRT group, whereas<50% in the CG reached that threshold. The between-group analysis indicated that the RBRT group improved performance on all performance tasks more than the CG (ES = -2.23 to 1.10; p <= 0.05). These findings demonstrate that substituting part of a standard soccer training regimen with RBRT can enhance youth soccer players' sprinting, CoD, jumping, and RSA performance.
KW - musculoskeletal and neural physiological phenomena
KW - human physical conditioning
KW - movement
KW - muscle strength
KW - youth team sports
Y1 - 2023
U6 - https://doi.org/10.1080/02640414.2023.2184770
SN - 0264-0414
SN - 1466-447X
VL - 40
IS - 24
SP - 2688
EP - 2696
PB - Routledge, Taylor & Francis Group
CY - London
ER -
TY - JOUR
A1 - Negra, Yassine
A1 - Chaabene, Helmi
A1 - Fernandez-Fernandez, Jaime
A1 - Sammoud, Senda
A1 - Bouguezzi, Raja
A1 - Prieske, Olaf
A1 - Granacher, Urs
T1 - Short-term plyometric Jump training improves repeated-sprint ability in prepuberal male soccer players
JF - Journal of strength and conditioning research : the research journal of the NSCA
N2 - This study examined the effects of a short-term (i.e., 8 weeks) combined horizontal and vertical plyometric jump training (PJT) program in combination with regular soccer-specific training as compared with soccer-specific training only on jump and change of direction (CoD) performances, speed, and repeated-sprint ability (RSA) in prepuberal male soccer players. Twenty-four players were recruited and randomly assigned to either a PJT group (PJT(G); n = 13; 12.7 +/- 0.2 years) or an active control group (CONG; n = 11; 12.7 +/- 0.2 years). The outcome measures included tests for the assessment of jump performance (drop jump from 20- to 40-cm height [DJ20 and DJ40] and 3-hop test [THT]), speed (20-m sprint), CoD (T-test), and RSA (20-m repeated shuttle sprint). Data were analyzed using magnitude-based inferences. Within-group analyses revealed large performance improvements in the T-test (d = -1.2), DJ20 (d = 3.7), DJ40 (d = 3.6), THT (d = 0.6), and the RSA(total) (d = -1.6) in the PJT(G). Between-group analyses showed greater performance improvements in the T-test (d = -2.9), 20-m sprint time (d = -2.0), DJ20 (d = 2.4), DJ40 (d = 2.0), THT (d = 1.9), RSA(best) (d = -1.9), and the RSA(total) (d = -1.9) in the PJT(G) compared with CONG. Eight weeks of an in-season PJT in addition to regular soccer-specific training induced larger increases in measures of physical fitness in prepuberal male soccer players compared with regular soccer-specific training only. More specifically, PJT was effective in improving RSA performance.
KW - youth
KW - stretch-shortening cycle
KW - athletic performance
KW - soccer
Y1 - 2020
U6 - https://doi.org/10.1519/JSC.0000000000002703
SN - 1064-8011
SN - 1533-4287
VL - 34
IS - 11
SP - 3241
EP - 3249
PB - Lippincott Williams & Wilkins
CY - Philadelphia
ER -
TY - GEN
A1 - Mkaouer, Bessem
A1 - Hammoudi-Nassib, Sarra
A1 - Amara, Samiha
A1 - Chaabène, Helmi
T1 - Evaluating the physical and basic gymnastics skills assessment for talent identification in men’s artistic gymnastics proposed by the International Gymnastics Federation
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - This study aimed to determine the specific physical and basic gymnastics skills considered critical in gymnastics talent identification and selection as well as in promoting men’s artistic gymnastics performances. Fifty-one boys from a provincial gymnastics team (age 11.03 ± 0.95 years; height 1.33 ± 0.05 m; body mass 30.01 ± 5.53 kg; body mass index [BMI] 16.89 ± 3.93 kg/m²) regularly competing at national level voluntarily participated in this study. Anthropometric measures as well as the men’s artistic gymnastics physical test battery (i.e., International Gymnastics Federation [FIG] age group development programme) were used to assess the somatic and physical fitness profile of participants, respectively. The physical characteristics assessed were: muscle strength, flexibility, speed, endurance, and muscle power. Test outcomes were subjected to a principal components analysis to identify the most representative factors. The main findings revealed that power speed, isometric and explosive strength, strength endurance, and dynamic and static flexibility are the most determinant physical fitness aspects of the talent selection process in young male artistic gymnasts. These findings are of utmost importance for talent identification, selection, and development.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 691
KW - young male gymnast
KW - fitness performance
KW - assessment
KW - selection
KW - development
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460049
SN - 1866-8364
IS - 691
SP - 383
EP - 392
ER -
TY - JOUR
A1 - Mkaouer, Bessem
A1 - Hammoudi-Nassib, Sarra
A1 - Amara, Samiha
A1 - Chaabene, Helmi
T1 - Evaluating the physical and basic gymnastics skills assessment for International Gymnastics Federation
JF - Biology of Sport
N2 - This study aimed to determine the specific physical and basic gymnastics skills considered critical in gymnastics talent identification and selection as well as in promoting men's artistic gymnastics performances. Fifty-one boys from a provincial gymnastics team (age 11.03 ± 0.95 years; height 1.33 ± 0.05 m; body mass 30.01 ± 5.53 kg; body mass index [BMI] 16.89 ± 3.93 kg/m²) regularly competing at national level voluntarily participated in this study. Anthropometric measures as well as the men's artistic gymnastics physical test battery (i.e., International Gymnastics Federation [FIG] age group development programme) were used to assess the somatic and physical fitness profile of participants, respectively. The physical characteristics assessed were: muscle strength, flexibility, speed, endurance, and muscle power. Test outcomes were subjected to a principal components analysis to identify the most representative factors. The main findings revealed that power speed, isometric and explosive strength, strength endurance, and dynamic and static flexibility are the most determinant physical fitness aspects of the talent selection process in young male artistic gymnasts. These findings are of utmost importance for talent identification, selection, and development.
KW - Young male gymnast
KW - Fitness performance
KW - Assessment
KW - Selection
KW - Development
Y1 - 2018
U6 - https://doi.org/10.5114/biolsport.2018.78059
SN - 0860-021X
SN - 2083-1862
VL - 35
IS - 4
SP - 383
EP - 392
PB - Inst Sport
CY - Warsaw
ER -
TY - JOUR
A1 - Markov, Adrian
A1 - Hauser, Lukas
A1 - Chaabene, Helmi
T1 - Effects of concurrent strength and endurance training on measures of physical fitness in healthy middle-aged and older adults
BT - a systematic review with meta-analysis
JF - Sports medicine : an international journal of applied medicine and science in sport and exercise
N2 - Background
There is evidence that in older adults the combination of strength training (ST) and endurance training (ET) (i.e., concurrent training [CT]) has similar effects on measures of muscle strength and cardiorespiratory endurance (CRE) compared with single-mode ST or ET, respectively. Therefore, CT seems to be an effective method to target broad aspects of physical fitness in older adults.
Objectives
The aim was to examine the effects of CT on measures of physical fitness (i.e., muscle strength, power, balance and CRE) in healthy middle-aged and older adults aged between 50 and 73 years. We also aimed to identify key moderating variables to guide training prescription.
Study Design
We conducted a systematic review with meta-analysis of randomized controlled trials.
Data Sources
The electronic databases PubMed, Web of Science Core Collection, MEDLINE and Google Scholar were systematically searched until February 2022.
Eligibility Criteria for Selecting Studies We included randomized controlled trials that examined the effects of CT versus passive controls on measures of physical fitness in healthy middle-aged and older adults aged between 50 and 73 years.
Results
Fifteen studies were eligible, including a total of 566 participants. CT induced moderate positive effects on muscle strength (standardized mean difference [SMD] = 0.74) and power (SMD = 0.50), with a small effect on CRE (SMD = 0.48). However, no significant effects were detected for balance (p > 0.05). Older adults > 65 years (SMD = 1.04) and females (SMD = 1.05) displayed larger improvements in muscle strength compared with adults <= 65 years old (SMD = 0.60) and males (SMD = 0.38), respectively. For CRE, moderate positive effects (SMD = 0.52) were reported in those <= 65 years old only, with relatively larger gains in females (SMD = 0.55) compared with males (SMD = 0.45). However, no significant differences between all subgroups were detected. Independent single training factor analysis indicated larger positive effects of 12 weeks (SMD = 0.87 and 0.88) compared with 21 weeks (SMD = 0.47 and 0.29) of CT on muscle strength and power, respectively, while for CRE, 21 weeks of CT resulted in larger gains (SMD = 0.62) than 12 weeks (SMD = 0.40). For CT frequency, three sessions per week produced larger beneficial effects (SMD = 0.91) on muscle strength compared with four sessions (SMD = 0.55), whereas for CRE, moderate positive effects were only noted after four sessions per week (SMD = 0.58). A session duration of > 30-60 min generated larger improvements in muscle strength (SMD = 0.99) and power (SMD = 0.88) compared with > 60-90 min (SMD = 0.40 and 0.29, respectively). However, for CRE, longer session durations (i.e., > 60-90 min) seem to be more effective (SMD = 0.61) than shorter ones (i.e., > 30-60 min) (SMD = 0.34). ET at moderate-to-near maximal intensities produced moderate (SMD = 0.64) and small positive effects (SMD = 0.49) on muscle strength and CRE, respectively, with no effects at low intensity ET (p > 0.05). Finally, intra-session ST before ET produced larger gains in muscle strength (SMD = 1.00) compared with separate sessions (SMD = 0.55), whereas ET and ST carried out separately induced larger improvements in CRE (SMD = 0.58) compared with intra-session ET before ST (SMD = 0.49).
Conclusions
CT is an effective method to improve measures of physical fitness (i.e., muscle strength, power, and CRE) in healthy middle-aged and older adults aged between 50 and 73 years, regardless of sex. Results of independent single training factor analysis indicated that the largest effects on muscle strength were observed after 12 weeks of training, > 30-60 min per session, three sessions per week, higher ET intensities and when ST preceded ET within the same session. For CRE, the largest effects were noted after 21 weeks of training, four sessions per week, > 60-90 min per session, higher ET intensities and when ET and ST sessions were performed separately. Regarding muscle power, the largest effects were observed after 12 weeks of training and > 30-60 min per session.
Y1 - 2022
U6 - https://doi.org/10.1007/s40279-022-01764-2
SN - 0112-1642
SN - 1179-2035
VL - 53
IS - 2
SP - 437
EP - 455
PB - Springer
CY - Heidelberg
ER -
TY - JOUR
A1 - Lesinski, Melanie
A1 - Prieske, Olaf
A1 - Chaabene, Helmi
A1 - Granacher, Urs
T1 - Seasonal effects of strength endurance vs. power training in young female soccer athletes
JF - Journal of strength and conditioning research : the research journal of the NSCA
N2 - Lesinski, M, Prieske, O, Chaabene, H, and Granacher, U. Seasonal effects of strength endurance vs. power training in young female soccer athletes. J Strength Cond Res 35(12S): S90-S96, 2021-This study examined the seasonal effects of strength endurance training (SET) vs. power training (PT) on physical fitness and body composition in young female soccer players. Thirty-six young female elite soccer players (15 +/- 1 years; maturity offset +3 +/- 1 years) were allocated to progressive SET (n = 19) or PT (n = 17). Over the course of one soccer season, SET performed slow movement velocity, moderate intensity (50-60% of the 1 repetition maximum [1RM]; 20-40 repetitions) strength exercises while PT performed moderate-to-high intensity (50-95% of the 1RM; 3-8 repetitions), high movement velocity strength exercises (2 sessions center dot wk(-1)). Before and after training, tests were performed for the assessment of muscle strength (1RM leg press), jump performance (countermovement jump [CMJ], drop jump [DJ]), muscular endurance (ventral Bourban test), linear speed (10 m, 20 m), change-of-direction (CoD) speed (T-test), dynamic balance (Y-balance test), sport-specific performance (kicking velocity), and body composition (lean body mass and fat mass). An analysis of covariance was used to test for between-group differences at post-test with baseline values as covariate. No significant between-group differences were observed in terms of total training volume over the respective soccer seasons (p = 0.069; d = 0.68). At post-test, SET showed significantly better ventral Bourban and T-test performances (d = 1.28-2.28; p = 0.000-0.001) compared with PT. However, PT resulted in significantly better 1RM leg press, DJ, 10-m, and 20-m sprint performances (d = 0.85-1.44; p = 0.000-0.026). No significant between-group differences were observed at post-test for CMJ, Y-balance test, kicking performance, and body composition (d = 0.20-0.74, p = 0.051-0.594). Our findings are mainly in accordance with the principle of training specificity. Both SET and PT are recommended to be implemented in young female elite soccer players according to the respective training period.
KW - strength training
KW - elite
KW - training specificity
KW - soccer players
KW - muscle
KW - endurance
KW - periodization
Y1 - 2021
U6 - https://doi.org/10.1519/JSC.0000000000003564
SN - 1064-8011
SN - 1533-4287
VL - 35
IS - Supplement 12
SP - S90
EP - S96
PB - Lippincott Williams & Wilkins
CY - Philadelphia
ER -
TY - JOUR
A1 - Lehmann, Nico
A1 - Kuhn, Yves-Alain
A1 - Keller, Martin
A1 - Aye, Norman
A1 - Herold, Fabian
A1 - Draganski, Bogdan
A1 - Taube, Wolfgang
A1 - Taubert, Marco
T1 - Brain activation during active balancing and its behavioral relevance in younger and older adults
BT - a functional near-infrared spectroscopy (fNIRS) study
JF - Frontiers in Aging Neuroscience
N2 - Age-related deterioration of balance control is widely regarded as an important phenomenon influencing quality of life and longevity, such that a more comprehensive understanding of the neural mechanisms underlying this process is warranted.
Specifically, previous studies have reported that older adults typically show higher neural activity during balancing as compared to younger counterparts, but the implications of this finding on balance performance remain largely unclear.
Using functional near-infrared spectroscopy (fNIRS), differences in the cortical control of balance between healthy younger (n = 27) and older (n = 35) adults were explored.
More specifically, the association between cortical functional activity and balance performance across and within age groups was investigated. To this end, we measured hemodynamic responses (i.e., changes in oxygenated and deoxygenated hemoglobin) while participants balanced on an unstable device.
As criterion variables for brain-behavior-correlations, we also assessed postural sway while standing on a free-swinging platform and while balancing on wobble boards with different levels of difficulty.
We found that older compared to younger participants had higher activity in prefrontal and lower activity in postcentral regions.
Subsequent robust regression analyses revealed that lower prefrontal brain activity was related to improved balance performance across age groups, indicating that higher activity of the prefrontal cortex during balancing reflects neural inefficiency.
We also present evidence supporting that age serves as a moderator in the relationship between brain activity and balance, i.e., cortical hemodynamics generally appears to be a more important predictor of balance performance in the older than in the younger. Strikingly, we found that age differences in balance performance are mediated by balancing-induced activation of the superior frontal gyrus, thus suggesting that differential activation of this region reflects a mechanism involved in the aging process of the neural control of balance.
Our study suggests that differences in functional brain activity between age groups are not a mere by-product of aging, but instead of direct behavioral relevance for balance performance.
Potential implications of these findings in terms of early detection of fall-prone individuals and intervention strategies targeting balance and healthy aging are discussed.
KW - aging
KW - neuroimaging
KW - functional near-infrared spectroscopy (fNIRS)
KW - balance
KW - postural control
KW - prefrontal cortex
KW - neural inefficiency
Y1 - 2022
U6 - https://doi.org/10.3389/fnagi.2022.828474
SN - 1663-4365
VL - 14
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Kotthaus, Jochem
A1 - Schäfer, Matthias
A1 - Stankovic, Nikola
A1 - Weitzel, Gerrit
T1 - How soccer becomes politics
BT - a case study on the communication of a transnational popular media event
JF - International journal of sport communication
N2 - In this case study, the authors elaborate on the narrative structure of transnational popular media events. Drawing from Dayan and Katz's concept of media events and Julia Sonnevend's exceptional work on iconic global media events, they argue that fundamental changes in the way occurrences are being reported on and news is structured must be considered. Allowing for recent technological advancements, the role of the consumer and the compression of time in media use, the authors develop a methodological and theoretical framework fitting a more mundane and everyday life-based approach. They derive their results from the analysis of the "Podgorica Media Event," a news cycle emerging from a racist incident during an international soccer game between England and Montenegro. Based on the body of 250 international news pieces, they identify a primary mother narration and a distinctive narration as the typical ways of storytelling on a transnational level. While differing greatly in content, aspects of transnational popular media events serve to protect and reify the cultural background they are grounded in on a national level. Thus, we assume that sport, or, more specifically, soccer, may become political in media communication not by the impact of state government but by the consumers themselves choosing and developing a popular media event in the first place.
KW - banal nationalism
KW - digital media
KW - everyday life
KW - prosumer
KW - racism
Y1 - 2021
U6 - https://doi.org/10.1123/ijsc.2020-0320
SN - 1936-3915
SN - 1936-3907
VL - 14
IS - 3
SP - 428
EP - 447
PB - Human Kinetics Publ.
CY - Champaign
ER -
TY - JOUR
A1 - Jebabli, Nidhal
A1 - Zouhal, Hassane
A1 - Boullosa, Daniel
A1 - Govindasamy, Karuppasamy
A1 - Tourny, Claire
A1 - Hackney, Anthony C.
A1 - Granacher, Urs
A1 - Ben Abderrahman, Abderraouf
T1 - The effects of preferred music and its timing on performance, pacing, and psychophysiological responses during the 6-min test
JF - Journal of human kinetics
N2 - The aim of this study was to investigate the effects of listening to preferred music during a warm up or exercise, on performance during a 6-min all-out exercise test (6-MT) in young adult males. Twenty-five healthy males volunteered to participate in this study. Following a within subject design, participants performed three test conditions (MDT: music during the test; MDW: music during the warm-up; WM: without music) in random order. Outcomes included mean running speed over the 6-min test (MRS6), total distance covered (TDC), heart rate responses (HRpeak, HRmean), blood lactate (3-min after the test), and the rating of perceived exertion (RPE); additionally, feeling scale scores were recorded. Listening to preferred music during running resulted in significant TDC (Delta up arrow 10%, p=0.006, ES=0.80) and MRS6 (Delta up arrow 14%, p=0.012, ES=1.02) improvement during the 6-MT, improvement was also noted for the warm-up with music condition (TDC:Delta up arrow 8%, p=0.028, ES=0.63; MRS6:Delta up arrow 8%, p=0.032, ES=0.61). A similar reverse "J-shaped" pacing profile was detected during the three conditions. Blood lactate was lower in the MDT condition by 8% (p=0.01, ES=1.10), but not the MDW condition, compared to MW. In addition, no statistically significant differences were found between the test sessions for the HR, RPE, and feeling scale scores. In conclusion, listening to music during exercise testing would be more beneficial for optimal TDC and MRS6 performances compared to MDW and WM.
KW - rating of perceived exertion
KW - work-rate distribution
KW - blood lactate;
KW - aerobic exercise
Y1 - 2022
U6 - https://doi.org/10.2478/hukin-2022-0038
SN - 1640-5544
SN - 1899-7562
VL - 82
IS - 1
SP - 123
EP - 133
PB - Academy of Physical Education
CY - Katowice
ER -
TY - GEN
A1 - Jebabli, Nidhal
A1 - Granacher, Urs
A1 - Selmi, Mohamed Amin
A1 - Al-Haddabi, Badriya
A1 - Behm, David George
A1 - Chaouachi, Anis
A1 - Haj Sassi, Radhouane
T1 - Listening to preferred music improved running performance without changing the pacing pattern during a 6 minute run test with young male adults
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Several studies have investigated the effects of music on both submaximal and maximal exercise performance at a constant work-rate. However, there is a lack of research that has examined the effects of music on the pacing strategy during self-paced exercise. The aim of this study was to examine the effects of preferred music on performance and pacing during a 6 min run test (6-MSPRT) in young male adults. Twenty healthy male participants volunteered for this study. They performed two randomly assigned trials (with or without music) of a 6-MSPRT three days apart. Mean running speed, the adopted pacing strategy, total distance covered (TDC), peak and mean heart rate (HRpeak, HRmean), blood lactate (3 min after the test), and rate of perceived exertion (RPE) were measured. Listening to preferred music during the 6-MSPRT resulted in significant TDC improvement (?10%; p = 0.016; effect size (ES) = 0.80). A significantly faster mean running speed was observed when listening to music compared with no music. The improvement of TDC in the present study is explained by a significant overall increase in speed (main effect for conditions) during the music trial. Music failed to modify pacing patterns as suggested by the similar reversed “J-shaped” profile during the two conditions. Blood-lactate concentrations were significantly reduced by 9% (p = 0.006, ES = 1.09) after the 6-MSPRT with music compared to those in the control condition. No statistically significant differences were found between the test conditions for HRpeak, HRmean, and RPE. Therefore, listening to preferred music can have positive effects on exercise performance during the 6-MSPRT, such as greater TDC, faster running speeds, and reduced blood lactate levels but has no effect on the pacing strategy.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 696
KW - RPE
KW - work-rate distribution
KW - blood lactate
KW - aerobic exercise
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-471884
SN - 1866-8364
IS - 696
ER -
TY - JOUR
A1 - Jafarnezhadgero, AmirAli
A1 - Ghorbanloo, Farshad
A1 - Fatollahi, Amir
A1 - Dionisio, Valdeci Carlos
A1 - Granacher, Urs
T1 - Effects of an elastic resistance band exercise program on kinetics and muscle activities during walking in young adults with genu valgus
BT - A double-blinded randomized controlled trial
JF - Clinical biomechanics : a journal affiliated to the International Society of Biomechanics and the American Society of Biomechanics
N2 - Background:
This double-blinded randomized-controlled-trial aimed to identify the effects of an elastic band resistance training on walking kinetics and muscle activities in young adults with genu valgus.
Methods:
Forty-two male young adults aged 22.5(2.7) years with genu valgus were randomly allocated to two experimental groups. The intervention group (n = 21) conducted a 14-weeks elastic band resistance training. The control group was passive during the intervention period and received the same treatment after the post-tests. Pre and post training, ground reaction forces and lower limb muscle activities were recorded during walking.
Findings:
Results revealed significant group-by-time interactions for peak medial ground reaction force and timeto-peak for posterior ground reaction force in favor of the intervention group (p < 0.012; d = 0.83-3.76). Resistance training with elastic bands resulted in significantly larger peak medial ground reaction force (p < 0.001; d = 1.45) and longer time-to-peak for posterior ground reaction force (p < 0.001; d = 1.85). Finding showed significant group-by-time interactions for peak positive free moment amplitudes in favor of the intervention group (p < 0.001; d = 1.18-2.02). Resistance training resulted in a lower peak positive free moment amplitude (p = 0.001; d = 1.46). With regards to muscle activities, the analysis revealed significant group-by time interactions for rectus femoris and gluteus medius activities during the push-off phase in favor of the intervention group (p < 0.038; d = 0.68-0.89). Resistance training induced higher rectus femoris (p = 0.038; d = 0.84) and gluteus medius (p = 0.007; d = 0.54) activities.
Interpretation:
This study proved the effectiveness of resistance training using elastic bands on kinetics and muscle activities during walking in male adults with genu valgus disorder. Given that this training regime is low cost, effective, and easy-to-administer, we suggest that it should be implemented as a rehabilitative or preventive means for young adults with genu valgus.
KW - Free moment
KW - Gait
KW - Knee valgus
KW - Loading rate
KW - Theraband training
Y1 - 2021
U6 - https://doi.org/10.1016/j.clinbiomech.2020.105215
SN - 0268-0033
SN - 1879-1271
VL - 81
PB - Elsevier Science
CY - Amsterdam [u.a.]
ER -
TY - JOUR
A1 - Jafarnezhadgero, Amir Ali
A1 - Piran Hamlabadi, Milad
A1 - Sajedi, Heidar
A1 - Granacher, Urs
T1 - Recreational runners who recovered from COVID-19 show different running kinetics and muscle activities compared with healthy controls
JF - Gait & posture : official journal of Gait and Clinical Movement Analysis Society, European Society of Movement Analysis in Adults and Children, Società Italiana di Analisi del Movimento in Clinica, International Society for Posture and Gait Research
N2 - Background:
Social isolation through quarantine represents an effective means to prevent COVID-19 infection. A negative side-effect of quarantine is low physical activity.
Research question:
What are the differences of running kinetics and muscle activities of recreational runners with a history of COVID-19 versus healthy controls?
Methods:
Forty men and women aged 20-30 years participated in this study and were divided into two experimental groups. Group 1 (age: 24.1 +/- 2.9) consisted of participants with a history of COVID-19 (COVID group) and group 2 (age: 24.2 +/- 2.7) of healthy age and sex-matched controls (controls). Both groups were tested for their running kinetics using a force plate and electromyographic activities (i.e., tibialis anterior [TA], gastrocnemius medialis [Gas-M], biceps femoris [BF], semitendinosus [ST], vastus lateralis [VL], vastus medialis [VM], rectus femoris [RF], gluteus medius [Glut-M]).
Results:
Results demonstrated higher peak vertical (p = 0.029; d=0.788) and medial (p = 0.004; d=1.119) ground reaction forces (GRFs) during push-off in COVID individuals compared with controls. Moreover, higher peak lateral GRFs were found during heel contact (p = 0.001; d=1.536) in the COVID group. COVID-19 individuals showed a shorter time-to-reach the peak vertical (p = 0.001; d=3.779) and posterior GRFs (p = 0.005; d=1.099) during heel contact. Moreover, the COVID group showed higher Gas-M (p = 0.007; d=1.109) and lower VM activity (p = 0.026; d=0.811) at heel contact.
Significance:
Different running kinetics and muscle activities were found in COVID-19 individuals versus healthy controls. Therefore, practitioners and therapists are advised to implement balance and/or strength training to improve lower limbs alignment and mediolateral control during dynamic movements in runners who recovered from COVID-19.
KW - Quarantine
KW - Ground reaction force
KW - Electromyography
Y1 - 2022
U6 - https://doi.org/10.1016/j.gaitpost.2021.11.002
SN - 0966-6362
SN - 1879-2219
VL - 91
SP - 260
EP - 265
PB - Elsevier
CY - Amsterdam [u.a.]
ER -
TY - JOUR
A1 - Jafarnezhadgero, Amir Ali
A1 - Fatollahi, Amir
A1 - Granacher, Urs
T1 - Eight weeks of exercising on sand has positive effects on biomechanics of walking and muscle activities in individuals with pronated feet
BT - a randomized double-blinded controlled trial
JF - Sports : open access journal
N2 - This study aimed to investigate the effects of eight weeks of barefoot running exercise on sand versus control on measures of walking kinetics and muscle activities in individuals with diagnosed pronated feet. Sixty physically active male adults with pronated feet were randomly allocated into an intervention or a waiting control group. The intervention group conducted an 8-weeks progressive barefoot running exercise program on sand (e.g., short sprints) with three weekly sessions. Pre and post intervention, participants walked at a constant speed of 1.3 m/s +/- 5% on a 18 m walkway with a force plate embedded in the middle of the walkway. Results showed significant group-by-time interactions for peak impact vertical and lateral ground reaction forces. Training but not control resulted in significantly lower peak impact vertical and lateral ground reaction forces. Significant group-by-time interactions were observed for vastus lateralis activity during the loading phase. Training-induced increases were found for the vastus lateralis in the intervention but not in the control group. This study revealed that the applied exercise program is a suitable means to absorb ground reaction forces (e.g., lower impact vertical and lateral peaks) and increase activities of selected lower limb muscles (e.g., vastus lateralis) when walking on stable ground.
KW - flat foot
KW - free moment
KW - gait
KW - loading rate
KW - training
Y1 - 2022
U6 - https://doi.org/10.3390/sports10050070
SN - 2075-4663
VL - 10
IS - 5
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Jafarnezhadgero, Amir Ali
A1 - Anvari, Maryam
A1 - Granacher, Urs
T1 - Long-term effects of shoe mileage on ground reaction forces and lower limb muscle activities during walking in individuals with genu varus
JF - Clinical biomechanics
N2 - Background:
Shoe mileage is an important factor that may influence the risk of sustaining injuries during walking. The aims of this study were to examine the effects of shoe mileage on ground reaction forces and activity of lower limb muscles during walking in genu varus individuals compared with controls.
Methods:
Fifteen healthy and 15 genu varus females received a new pair of running shoes. They were asked to wear these shoes over 6 months. Pre and post intervention, mechanical shoe testing was conducted and ground reaction forces and muscle activities of the right leg were recorded during walking at preferred gait speed.
Findings:
Significant group-by-time interactions were found for shoe stiffness, antero-posterior and vertical impact peak. We observed higher shoe stiffness and lower impact peaks after intervention in both groups with larger effect sizes in genu varus. Significant group-by-time interactions were identified for vastus medialis (loading phase) and rectus femoris (loading and push-off). For vastus medialis, significant decreases were found from pre-to-post during the loading phase in the control group. Rectus femoris activity was higher post intervention during the loading and push-off phases in both groups with larger effect sizes in genu varus.
Interpretation:
Our findings indicate that the observed changes in ground reaction forces are more prominent in genu varus individuals. Together with our findings on shoe stiffness, it seems appropriate to change running shoes after an intense wearing time of 6 months, particularly in genu varus individuals.
KW - footwear
KW - electromyography
KW - loading rate
KW - patients
Y1 - 2020
U6 - https://doi.org/10.1016/j.clinbiomech.2020.01.006
SN - 0268-0033
SN - 1879-1271
VL - 73
SP - 55
EP - 62
PB - Elsevier
CY - Oxford
ER -
TY - JOUR
A1 - Hortobagyi, Tibor
A1 - Deak, Dorina
A1 - Farkas, Dora
A1 - Blenyesi, Eszter
A1 - Torok, Katalin
A1 - Granacher, Urs
A1 - Tollar, Jozsef
T1 - Effects of exercise dose and detraining duration on mobility at late midlife
BT - a randomized clinical trial
JF - Gerontology
N2 - Background:
Office workers near retirement tend to be sedentary and can be prone to mobility limitations and diseases. We examined the dose effects of exergaming volume and duration of detraining on motor and cognitive function in office workers at late midlife to reduce sedentariness and mobility limitations.
Methods:
In an assessor-blinded randomized trial, 160 workers aged 55-65 years performed physically active video games in a nonimmersive form of virtual reality (exergaming) in small, supervised groups for 1 h, 1x, 2x, or 3x/week for 8 weeks followed by detraining for 8 and 16 weeks. Exergaming comprises high-intensity, full-body sensorimotor coordination, balance, endurance, and strengthening exercises. The primary outcome was the 6-minute walk test (6MWT), and secondary outcomes were body mass, self-reported physical activity, sleep quality, Berg Balance Scale, Short Physical Performance Battery, fast gait speed, dynamic balance, heart rate recovery after step test, and 6 cognitive tests.
Results:
The 3 groups were not different in any of the outcomes at baseline (all p > 0.05). The outcomes were stable and had acceptable reliability (intraclass correlation coefficients >= 0.334) over an 8-week control period. Training produced an inverted U-shaped dose response of no (1x), most (2x), and medium (3x/week) effects of exergaming volume in most motor and selected cognitive outcomes. The distance walked in the 6MWT (primary outcome) increased most (94 m, 19%, p < 0.05), medium (57 m, 12%, p < 0.05), and least (4 m, 1%) after exergaming 2x, 3x, or 0x (control) (all different p < 0.05). The highest responders tended to retain the exercise effects over 8 weeks of detraining, independent of training volume. This maintenance effect was less consistent after 16 weeks of detraining.
Conclusion:
Less was more during training and lasted longer after detraining. A medium dose volume of exergaming produced the largest clinically meaningful improvements in mobility and selected cognitive tests in 60-year-old office workers with mild mobility limitations and intact cognition.
KW - exercise
KW - dose response
KW - walking capacity
KW - cognitive function
Y1 - 2021
U6 - https://doi.org/10.1159/000513505
SN - 0304-324X
SN - 1423-0003
VL - 67
IS - 4
SP - 403
EP - 414
PB - Karger
CY - Basel
ER -
TY - GEN
A1 - Hirschmueller, Anja
A1 - Baur, Heiner
A1 - Braun, Sepp
A1 - Kreuz, Peter C.
A1 - Suedkamp, Norbert P
A1 - Niemeyer, Philipp
T1 - Rehabilitation after autologous chondrocyte implantation for isolated cartilage defects of the knee
N2 - Autologous chondrocyte implantation for treatment of isolated cartilage defects of the knee has become well established. Although various publications report technical modifications, clinical results, and cell-related issues, little is known about appropriate and optimal rehabilitation after autologous chondrocyte implantation. This article reviews the literature on rehabilitation after autologous chondrocyte implantation and presents a rehabilitation protocol that has been developed considering the best available evidence and has been successfully used for several years in a large number of patients who underwent autologous chondrocyte implantation for cartilage defects of the knee.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 367
KW - autologous chondrocyte implantation
KW - cartilage repair
KW - cartilage defect
KW - cell transplantation
KW - knee joint
KW - rehabilitation
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403170
ER -
TY - JOUR
A1 - Herold, Fabian
A1 - Theobald, Paula
A1 - Gronwald, Thomas
A1 - Rapp, Michael A.
A1 - Müller, Notger Germar
T1 - Going digital – a commentary on the terminology used at the intersection of physical activity and digital health
JF - European review of aging and physical activity
N2 - In recent years digital technologies have become a major means for providing health-related services and this trend was strongly reinforced by the current Coronavirus disease 2019 (COVID-19) pandemic. As it is well-known that regular physical activity has positive effects on individual physical and mental health and thus is an important prerequisite for healthy aging, digital technologies are also increasingly used to promote unstructured and structured forms of physical activity. However, in the course of this development, several terms (e.g., Digital Health, Electronic Health, Mobile Health, Telehealth, Telemedicine, and Telerehabilitation) have been introduced to refer to the application of digital technologies to provide health-related services such as physical interventions. Unfortunately, the above-mentioned terms are often used in several different ways, but also relatively interchangeably. Given that ambiguous terminology is a major source of difficulty in scientific communication which can impede the progress of theoretical and empirical research, this article aims to make the reader aware of the subtle differences between the relevant terms which are applied at the intersection of physical activity and Digital Health and to provide state-of-art definitions for them.
KW - Digital Health
KW - Electronic Health
KW - Mobile Health
KW - Telehealth
KW - Telemedicine
KW - Physical activity
KW - Physical training
KW - Aging
Y1 - 2022
U6 - https://doi.org/10.1186/s11556-022-00296-y
SN - 1861-6909
VL - 19
PB - Springer
CY - Berlin ; Heidelberg
ER -
TY - JOUR
A1 - Henschke, Jakob
A1 - Zecher, Mahli Megan
A1 - Mayer, Frank
A1 - Engel, Tilman
T1 - Contralateral repeated bout effect following preconditioning exercises
BT - a systematic review
JF - Sport sciences for health
N2 - Background Recent studies indicate the existence of a repeated bout effect on the contralateral untrained limb following eccentric and isometric contractions. Aims This review aims to summarize the evidence for magnitude, duration and differences of this effect following isometric and eccentric preconditioning exercises. Methods Medline, Cochrane, and Web of science were searched from January 1971 until September 2020. Randomized controlled trials, case-control studies and cross-sectional studies were identified by combining keywords and synonyms (e.g., "contralateral", "exercise", "preconditioning", "protective effect"). At least two of the following outcome parameters were mandatory for study inclusion: strength, muscle soreness, muscle swelling, limb circumference, inflammatory blood markers or protective index (relative change of aforementioned measures). Results After identifying 1979 articles, 13 studies were included. Most investigations examined elbow flexors and utilized eccentric isokinetic protocols to induce the contralateral repeated bout effect. The magnitude of protection was observed in four studies, smaller values of the contralateral when compared to the ipsilateral repeated bout effect were noted in three studies. The potential mechanism is thought to be of neural central nature since no differences in peripheral muscle activity were observed. Time course was examined in three investigations. One study showed a smaller protective effect following isometric preconditioning when compared to eccentric preconditioning exercises. Conclusions The contralateral repeated bout effect demonstrates a smaller magnitude and lasts shorter than the ipsilateral repeated bout effect. Future research should incorporate long-term controlled trials including larger populations to identify central mechanisms. This knowledge should be used in clinical practice to prepare immobilized limbs prospectively for an incremental load.
KW - musculoskeletal physiological phenomena
KW - muscle damage
KW - adaptation
KW - Crossover
KW - muscle soreness
KW - isometric contraction
Y1 - 2021
U6 - https://doi.org/10.1007/s11332-021-00804-0
SN - 1824-7490
SN - 1825-1234
VL - 18
IS - 1
SP - 1
EP - 10
PB - Soringer Italia
CY - Milan
ER -
TY - JOUR
A1 - Hammami, Raouf
A1 - Chaabene, Helmi
A1 - Kharrat, Fatma
A1 - Werfelli, Hanen
A1 - Duncan, Michael
A1 - Rebai, Haithem
A1 - Granacher, Urs
T1 - Acute effects of different balance exercise types on selected measures of physical fitness in youth female volleyball players
JF - BMC Sports Science, Medicine and Rehabilitation
N2 - Background
Earlier studies have shown that balance training (BT) has the potential to induce performance enhancements in selected components of physical fitness (i.e., balance, muscle strength, power, speed). While there is ample evidence on the long-term effects of BT on components of physical fitness in youth, less is known on the short-term or acute effects of single BT sessions on selected measures of physical fitness.
Objective
To examine the acute effects of different balance exercise types on balance, change-of-direction (CoD) speed, and jump performance in youth female volleyball players.
Methods
Eleven female players aged 14 years participated in this study. Three types of balance exercises (i.e., anterior, posterolateral, rotational type) were conducted in randomized order. For each exercise, 3 sets including 5 repetitions were performed. Before and after the performance of the balance exercises, participants were tested for their static balance (center of pressure surface area [CoP SA] and velocity [CoP V]) on foam and firm surfaces, CoD speed (T-Half test), and vertical jump height (countermovement jump [CMJ] height). A 3 (condition: anterior, mediolateral, rotational balance exercise type) × 2 (time: pre, post) analysis of variance was computed with repeated measures on time.
Results
Findings showed no significant condition × time interactions for all outcome measures (p > 0.05). However, there were small main effects of time for CoP SA on firm and foam surfaces (both d = 0.38; all p < 0.05) with no effect for CoP V on both surface conditions (p > 0.05). For CoD speed, findings showed a large main effect of time (d = 0.91; p < 0.001). However, for CMJ height, no main effect of time was observed (p > 0.05).
Conclusions
Overall, our results indicated small-to-large changes in balance and CoD speed performances but not in CMJ height in youth female volleyball players, regardless of the balance exercise type. Accordingly, it is recommended to regularly integrate balance exercises before the performance of sport-specific training to optimize performance development in youth female volleyball players.
KW - Postural stability
KW - Conditioning activity
KW - Short‐term effect
KW - Team sports
KW - Youth
Y1 - 2021
U6 - https://doi.org/10.1186/s13102-021-00249-5
SN - 1758-2555
VL - 13
PB - BioMed Central
CY - London
ER -
TY - GEN
A1 - Hammami, Raouf
A1 - Chaabene, Helmi
A1 - Kharrat, Fatma
A1 - Werfelli, Hanen
A1 - Duncan, Michael
A1 - Rebai, Haithem
A1 - Granacher, Urs
T1 - Acute effects of different balance exercise types on selected measures of physical fitness in youth female volleyball players
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Background
Earlier studies have shown that balance training (BT) has the potential to induce performance enhancements in selected components of physical fitness (i.e., balance, muscle strength, power, speed). While there is ample evidence on the long-term effects of BT on components of physical fitness in youth, less is known on the short-term or acute effects of single BT sessions on selected measures of physical fitness.
Objective
To examine the acute effects of different balance exercise types on balance, change-of-direction (CoD) speed, and jump performance in youth female volleyball players.
Methods
Eleven female players aged 14 years participated in this study. Three types of balance exercises (i.e., anterior, posterolateral, rotational type) were conducted in randomized order. For each exercise, 3 sets including 5 repetitions were performed. Before and after the performance of the balance exercises, participants were tested for their static balance (center of pressure surface area [CoP SA] and velocity [CoP V]) on foam and firm surfaces, CoD speed (T-Half test), and vertical jump height (countermovement jump [CMJ] height). A 3 (condition: anterior, mediolateral, rotational balance exercise type) × 2 (time: pre, post) analysis of variance was computed with repeated measures on time.
Results
Findings showed no significant condition × time interactions for all outcome measures (p > 0.05). However, there were small main effects of time for CoP SA on firm and foam surfaces (both d = 0.38; all p < 0.05) with no effect for CoP V on both surface conditions (p > 0.05). For CoD speed, findings showed a large main effect of time (d = 0.91; p < 0.001). However, for CMJ height, no main effect of time was observed (p > 0.05).
Conclusions
Overall, our results indicated small-to-large changes in balance and CoD speed performances but not in CMJ height in youth female volleyball players, regardless of the balance exercise type. Accordingly, it is recommended to regularly integrate balance exercises before the performance of sport-specific training to optimize performance development in youth female volleyball players.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 713
KW - Postural stability
KW - Conditioning activity
KW - Short‐term effect
KW - Team sports
KW - Youth
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-517477
SN - 1866-8364
IS - 713
ER -
TY - JOUR
A1 - Hagoort, Iris
A1 - Vuillerme, Nicolas
A1 - Hortobágyi, Tibor
A1 - Lamoth, Claudine J. C.
T1 - Outcome-dependent effects of walking speed and age on quantitative and qualitative gait measures
JF - Gait & posture
N2 - Background: Walking speed predicts many clinical outcomes in old age. However, a comprehensive assessment of how walking speed affects accelerometer based quantitative and qualitative gait measures in younger and older adults is lacking. Research question: What is the relationship between walking speed and quantitative and qualitative gait outcomes in younger and older adults? Methods: Younger (n = 27, age: 21.6) and older participants (n = 27, age: 69.5) completed 340 steps on a treadmill at speeds of 0.70 to a maximum of 1.75 m.s(-1). We used generalized additive mixed models to determine the relationship between walking speed and quantitative (stride length, stride time, stride frequency and their variability) and qualitative (stride regularity, stability, smoothness, symmetry, synchronization, predictability) gait measures extracted from trunk accelerations. Results: The type of relationship between walking speed and the majority of gait measures (quantitative and qualitative) was characterized as logarithmic, with more prominent speed-effects at speeds below 1.20 m.s(-1). Changes in quantitative measures included shorter strides, longer stride times, and a lower stride frequency, with more variability at lower speeds independent of age. For qualitative measures, we found a decrease in gait symmetry, stability and regularity in all directions with decreasing speeds, a decrease in gait predictability (Vertical, V, anterior-posterior, AP) and stronger gait synchronization (AP-mediolateral, ML, AP-V), and direction dependent effects of gait smoothness, which decreased in V direction, but increased in AP and ML directions with decreasing speeds. We found outcome-dependent effects of age on the quantitative and qualitative gait measures, with either no differences between age-groups, age-related differences that existed regardless of speed, and age-related differences in the type of relationship with walking speed. Significance: The relationship between walking speed and quantitative and qualitative gait measures, and the effects of age on this relationship, depends on the type of gait measure studied.
KW - Gait quality and quantity
KW - Aging
KW - Walking speed
KW - Treadmill
KW - Generalized
KW - additive mixed models
Y1 - 2022
U6 - https://doi.org/10.1016/j.gaitpost.2022.01.001
SN - 0966-6362
SN - 1879-2219
VL - 93
SP - 39
EP - 46
PB - Elsevier
CY - Clare
ER -
TY - GEN
A1 - Granacher, Urs
A1 - Hortobágyi, Tibor
T1 - Exercise to improve mobility in healthy aging
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 897
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-432419
SN - 1866-8372
IS - 897
ER -
TY - JOUR
A1 - El-Ashker, Said
A1 - Chaabene, Helmi
A1 - Negra, Yassine
A1 - Prieske, Olaf
A1 - Granacher, Urs
T1 - Cardio-Respiratory Endurance Responses Following a Simulated 3 x 3 Minutes Amateur Boxing Contest in Elite Level Boxers
JF - Sports
N2 - This study aimed at examining physiological responses (i.e., oxygen uptake [VO2] and heart rate [HR]) to a semi-contact 3 x 3-min format, amateur boxing combat simulation in elite level male boxers. Eleven boxers aged 21.4 +/- 2.1 years (body height 173.4 +/- 3.7, body mass 74.9 +/- 8.6 kg, body fat 12.1 +/- 1.9, training experience 5.7 +/- 1.3 years) volunteered to participate in this study. They performed a maximal graded aerobic test on a motor-driven treadmill to determine maximum oxygen uptake (VO2max), oxygen uptake (VO2AT) and heart rate (HRAT) at the anaerobic threshold, and maximal heart rate (HRmax). Additionally, VO2 and peak HR (HRpeak) were recorded following each boxing round. Results showed no significant differences between VO2max values derived from the treadmill running test and VO2 outcomes of the simulated boxing contest (p > 0.05, d = 0.02 to 0.39). However, HRmax and HRpeak recorded from the treadmill running test and the simulated amateur boxing contest, respectively, displayed significant differences regardless of the boxing round (p < 0.01, d = 1.60 to 3.00). In terms of VO2 outcomes during the simulated contest, no significant between-round differences were observed (p = 0.19, d = 0.17 to 0.73). Irrespective of the boxing round, the recorded VO2 was >90% of the VO2max. Likewise, HRpeak observed across the three boxing rounds were >= 90% of the HRmax. In summary, the simulated 3 x 3-min amateur boxing contest is highly demanding from a physiological standpoint. Thus, coaches are advised to systematically monitor internal training load for instance through rating of perceived exertion to optimize training-related adaptations and to prevent boxers from overreaching and/or overtraining.
KW - aerobic metabolism
KW - physiological strain
KW - striking combat sports
KW - elite athletes
Y1 - 2018
U6 - https://doi.org/10.3390/sports6040119
SN - 2075-4663
VL - 6
IS - 4
PB - MDPI
CY - Basel
ER -
TY - GEN
A1 - El-Ashker, Said
A1 - Chaabene, Helmi
A1 - Negra, Yassine
A1 - Prieske, Olaf
A1 - Granacher, Urs
T1 - Cardio-Respiratory endurance responses following a simulated 3 x 3 minutes amateur boxing contest in elite level boxers
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - This study aimed at examining physiological responses (i.e., oxygen uptake [VO2] and heart rate [HR]) to a semi-contact 3 x 3-min format, amateur boxing combat simulation in elite level male boxers. Eleven boxers aged 21.4 +/- 2.1 years (body height 173.4 +/- 3.7, body mass 74.9 +/- 8.6 kg, body fat 12.1 +/- 1.9, training experience 5.7 +/- 1.3 years) volunteered to participate in this study. They performed a maximal graded aerobic test on a motor-driven treadmill to determine maximum oxygen uptake (VO2max), oxygen uptake (VO2AT) and heart rate (HRAT) at the anaerobic threshold, and maximal heart rate (HRmax). Additionally, VO2 and peak HR (HRpeak) were recorded following each boxing round. Results showed no significant differences between VO2max values derived from the treadmill running test and VO2 outcomes of the simulated boxing contest (p > 0.05, d = 0.02 to 0.39). However, HRmax and HRpeak recorded from the treadmill running test and the simulated amateur boxing contest, respectively, displayed significant differences regardless of the boxing round (p < 0.01, d = 1.60 to 3.00). In terms of VO2 outcomes during the simulated contest, no significant between-round differences were observed (p = 0.19, d = 0.17 to 0.73). Irrespective of the boxing round, the recorded VO2 was >90% of the VO2max. Likewise, HRpeak observed across the three boxing rounds were >= 90% of the HRmax. In summary, the simulated 3 x 3-min amateur boxing contest is highly demanding from a physiological standpoint. Thus, coaches are advised to systematically monitor internal training load for instance through rating of perceived exertion to optimize training-related adaptations and to prevent boxers from overreaching and/or overtraining.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 675
KW - aerobic metabolism
KW - physiological strain
KW - striking combat sports
KW - elite athletes
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472338
SN - 1866-8364
IS - 675
ER -
TY - JOUR
A1 - Dobberke, Jeanette
A1 - Baritello, Omar
A1 - Hadzic, Miralem
A1 - Völler, Heinz
A1 - Eichler, Sarah
A1 - Salzwedel, Annett
T1 - Test-retest reliability of center of pressure measures for postural control assessment in older cardiac patients
JF - Gait & posture : official journal of Gait and Clinical Movement Analysis Society (GCMAS) and European Society of Movement Analysis in Adults and Children (ESMAC)
N2 - Background
Elderly patients are a growing population in cardiac rehabilitation (CR). As postural control declines with age, assessment of impaired balance is important in older CR patients in order to predict fall risk and to initiate counteracting steps. Functional balance tests are subjective and lack adequate sensitivity to small differences, and are further subject to ceiling effects. A quantitative approach to measure postural control on a continuous scale is therefore desirable. Force plates are already used for this purpose in other clinical contexts, therefore could be a promising tool also for older CR patients. However, in this population the reliability of the assessment is not fully known.
Research question
Analysis of test-retest reliability of center of pressure (CoP) measures for the assessment of postural control using a force plate in older CR patients.
Methods
156 CR patients (> 75 years) were enrolled. CoP measures (path length (PL), mean velocity (MV), and 95% confidence ellipse area (95CEA)) were analyzed twice with an interval of two days in between (bipedal narrow stance, eyes open (EO) and closed (EC), three trials for each condition, 30 s per trial), using a force plate. For test-retest reliability estimation absolute differences (& UDelta;: T0-T1), intraclass correlation coefficients (ICC) with 95% confidence intervals, standard error of measurement and minimal detectable change were calculated.
Results
Under EO condition ICC were excellent for PL and MV (0.95) and good for 95CEA (0.88) with & UDelta; of 10.1 cm (PL), 0.3 cm/sec (MV) and 1.5 cm(2 )(95CEA) respectively. Under EC condition ICC were excellent (> 0.95) for all variables with larger & UDelta; (PL: 21.7 cm; MV: 0.7 cm/sec; 95CEA: 2.4 cm(2))
Significance
In older CR patients, the assessment of CoP measures using a force plate shows good to excellent test retest reliability.
KW - Cardiac rehabilitation
KW - Older patients
KW - Postural control
KW - Test-retest
KW - reliability
KW - Force plate
Y1 - 2022
U6 - https://doi.org/10.1016/j.gaitpost.2021.12.011
SN - 0966-6362
SN - 1879-2219
VL - 92
SP - 359
EP - 363
PB - Elsevier Science
CY - Amsterdam
ER -
TY - GEN
A1 - De Souza Silveira, Raul
A1 - Carlsohn, Anja
A1 - Langen, Georg
A1 - Mayer, Frank
A1 - Scharhag-Rosenberger, Friederike
T1 - Reliability and day-to-day variability of peak fat oxidation during treadmill ergometry
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Background:
Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fat peak ) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fat peak as well as its actual velocity (V PFO ) during treadmill ergometry. Our purpose was therefore, to assess the reliability and day-to-day variability of V PFO and Fat peak during treadmill ergometry running.
Methods:
Sixteen recreational athletes (f = 7, m = 9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m 2 ) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO 2peak ) and the velocities at the aerobic threshold (V LT ) and respiratory exchange ratio (RER) of 1.00 (V RER ) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70 % V LT ) followed by 5 stages of 6 min with equal increments (stage 1 = V LT , stage 5 = V RER ). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify V PFO and subsequently Fat peak . The reproducibility and variability of variables was verified with an int raclass correlation coef ficient (ICC), Pearson ’ s correlation coefficient, coefficient of variation (CV) an d the mean differences (bias) ± 95 % limits of agreement (LoA).
Results:
ICC, Pearson ’ s correlation and CV for V PFO and Fat peak were 0.98, 0.97, 5.0 %; and 0.90, 0.81, 7.0 %, respectively. Bias ± 95 % LoA was − 0.3 ± 0.9 km/h for V PFO and − 2±8%ofVO 2peak for Fat peak.
Conclusion:
In summary, relative and absolute reliability indicators for V PFO and Fat peak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 423
KW - peak fat oxidation
KW - reliability
KW - variability
KW - running
KW - treadmill ergometry
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407334
IS - 423
ER -
TY - JOUR
A1 - Davies, Michael J.
A1 - Drury, Benjamin
A1 - Ramirez-Campillo, Rodrigo
A1 - Chaabene, Helmi
A1 - Moran, Jason
T1 - Effect of plyometric training and biological maturation on jump and change of direction ability in female youth
JF - Journal of strength and conditioning research : the research journal of the NSCA / National Strength & Conditioning Association
N2 - Biological maturation has been shown to affect male youths' responses to plyometric training (PT). However, to date, no researcher has examined the effect of maturation on the effects of PT in female youth. We undertook the first controlled intervention study to examine this, focusing on adaptive responses to countermovement jump (CMJ), reactive strength index (RSI), and change of direction (COD) performance in groups of female youth divided by maturation status (years from peak height velocity [PHV]). The training program lasted 7 weeks with subjects undertaking 2 sessions of PT per week. In the mid-PHV group, there was a small increase (effect size; 90% confidence interval = 0.40; -0.23 to 1.03) in CMJ performance. No changes were observed in the post-PHV group (0.02; -0.68 to 0.72). For RSI, there was a moderate increase in the mid-PHV group (0.94; 0.29-1.59) with only a trivial increase in the post-PHV group (0.06; -0.65 to 0.76). The intervention exerted no positive effect on COD performance in any group. Plyometric training seems to enhance CMJ and RSI in female youth, although the magnitude of adaptation could be affected by maturation status. A twice-per-week program of multidirectional jumping and hopping, with bilateral and unilateral components, can be used as a preparatory precursor to physical education classes or recreational sport.
KW - girls
KW - exercise
KW - sport
KW - athlete
Y1 - 2021
U6 - https://doi.org/10.1519/JSC.0000000000003216
SN - 1064-8011
SN - 1533-4287
VL - 35
IS - 10
SP - 2690
EP - 2697
PB - Lippincott Williams & Wilkins
CY - Philadelphia
ER -
TY - GEN
A1 - Chaabene, Helmi
A1 - Prieske, Olaf
A1 - Lesinski, Melanie
A1 - Sandau, Ingo
A1 - Granacher, Urs
T1 - Short-term seasonal development of anthropometry, body composition, physical fitness, and sport-specific performance in young olympic weightlifters
T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - The aim of this study is to monitor short-term seasonal development of young Olympic weightlifters’ anthropometry, body composition, physical fitness, and sport-specific performance. Fifteen male weightlifters aged 13.2 ± 1.3 years participated in this study. Tests for the assessment of anthropometry (e.g., body-height, body-mass), body-composition (e.g., lean-body-mass, relative fat-mass), muscle strength (grip-strength), jump performance (drop-jump (DJ) height, countermovement-jump (CMJ) height, DJ contact time, DJ reactive-strength-index (RSI)), dynamic balance (Y-balance-test), and sport-specific performance (i.e., snatch and clean-and-jerk) were conducted at different time-points (i.e., T1 (baseline), T2 (9 weeks), T3 (20 weeks)). Strength tests (i.e., grip strength, clean-and-jerk and snatch) and training volume were normalized to body mass. Results showed small-to-large increases in body-height, body-mass, lean-body-mass, and lower-limbs lean-mass from T1-to-T2 and T2-to-T3 (∆0.7–6.7%; 0.1 ≤ d ≤ 1.2). For fat-mass, a significant small-sized decrease was found from T1-to-T2 (∆13.1%; d = 0.4) and a significant increase from T2-to-T3 (∆9.1%; d = 0.3). A significant main effect of time was observed for DJ contact time (d = 1.3) with a trend toward a significant decrease from T1-to-T2 (∆–15.3%; d = 0.66; p = 0.06). For RSI, significant small increases from T1-to-T2 (∆9.9%, d = 0.5) were noted. Additionally, a significant main effect of time was found for snatch (d = 2.7) and clean-and-jerk (d = 3.1) with significant small-to-moderate increases for both tests from T1-to-T2 and T2-to-T3 (∆4.6–11.3%, d = 0.33 to 0.64). The other tests did not change significantly over time (0.1 ≤ d ≤ 0.8). Results showed significantly higher training volume for sport-specific training during the second period compared with the first period (d = 2.2). Five months of Olympic weightlifting contributed to significant changes in anthropometry, body-composition, and sport-specific performance. However, hardly any significant gains were observed for measures of physical fitness. Coaches are advised to design training programs that target a variety of fitness components to lay an appropriate foundation for later performance as an elite athlete.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 685
KW - strength
KW - monitoring
KW - young athletes
KW - weight training
KW - somatic variables
KW - periodization
KW - training load
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472609
SN - 1866-8364
IS - 685
ER -
TY - JOUR
A1 - Chaabene, Helmi
A1 - Negra, Yassine
A1 - Moran, Jason
A1 - Prieske, Olaf
A1 - Sammoud, Senda
A1 - Ramirez-Campillo, Rodrigo
A1 - Granacher, Urs
T1 - Plyometric training improves not only measures of linear speed, power, and change-of-direction speed but also repeated sprint ability in young female handball players
JF - Journal of strength and conditioning research : the research journal of the NSCA
N2 - This study examined the effects of an 8-week plyometric training (PT) program on components of physical fitness in young female handball players. Twenty-one female adolescent handball players were assigned to an experimental group (EG, n = 12; age = 15.9 +/- 0.2 years) or an active control group (CG, n = 9, age = 15.9 +/- 0.3 years). While EG performed plyometric exercises in replacement of some handball-specific drills, CG maintained the regular training schedule. Baseline and follow-up tests were performed for the assessment of linear speed (i.e., 5-, 10-, and 20-m time), change-of-direction (CoD) speed (i.e., T-test time), muscle power (i.e., countermovement jump [CMJ] height and reactive strength index [RSI]), and repeated sprint ability (RSA) (RSA total time [RSA(total)], RSA best time [RSA(best)], and RSA fatigue index [RSA(FI)]). Data were analyzed using magnitude-based inferences. Within-group analyses for the EG revealed moderate-to-large improvements for the 5-m (effect size [ES] = 0.81 [0.1-1.5]), 10-m sprint time (ES = 0.84 [0.1-1.5]), RSI (ES = 0.75 [0.1-1.4]), RSA(FI) (ES = 0.65 [0.0-1.3]), and T-test time (ES = 1.46 [0.7-2.2]). Trivial-to-small ES was observed for RSA(best) (ES = 0.18 [-0.5 to 0.9]), RSA(total) (ES = 0.45 [-0.2 to 1.1]), 20-m sprint time (ES = 0.56 [-0.1 to 1.2]), and CMJ height (ES = 0.57 [-0.1 to 1.3]). For the CG, within-group analyses showed a moderate performance decline for T-test time (ES = -0.71 [-1.5 to 0.1]), small decreases for 5-m sprint time (ES = -0.46 [-1.2 to 0.3]), and a trivial decline for 10-m (ES = -0.10 [-0.9 to 0.7]) and 20-m sprint times (ES = -0.16 [-0.9 to 0.6]), RSA(total) (ES = 0.0 [-0.8 to 0.8]), and RSA(best) (ES = -0.20 [-0.9 to 0.6]). The control group achieved trivial-to-small improvements for CMJ height (ES = 0.10 [-0.68 to 0.87]) and RSI (ES = 0.30 [-0.5 to 1.1]). In conclusion, a short-term in-season PT program, in replacement of handball-specific drills, is effective in improving measures of physical fitness (i.e., linear/CoD speed, jumping, and RSA) in young female handball players.
KW - stretch-shortening cycle
KW - physical fitness
KW - young athletes
Y1 - 2021
U6 - https://doi.org/10.1519/JSC.0000000000003128
SN - 1064-8011
SN - 1533-4287
VL - 35
IS - 8
SP - 2230
EP - 2235
PB - Lippincott Williams & Wilkins
CY - Philadelphia
ER -
TY - JOUR
A1 - Busch, Aglaja
A1 - Trounson, Karl M.
A1 - Browne, Peter
A1 - Robertson, Sam
T1 - Effects of lower limb light-weight wearable resistance on running biomechanics
JF - Journal of biomechanics : affiliated with the American Society of Biomechanics, the European Society of Biomechanics, the International Society of Biomechanics, the Japanese Society for Clinical Biomechanics and Related Research and the Australian and New Zealand Society of Biomechanics
N2 - Wearable resistance allows individualized loading for sport specific movements and can lead to specific strength adaptations benefiting the athlete. The objective was to determine biomechanical changes during running with lower limb light-weight wearable resistance. Fourteen participants (age: 28 +/- 4 years; height: 180 +/- 8 cm; body mass: 77 +/- 6 kg) wore shorts and calf sleeves of a compression suit allowing attachment of light loads. Participants completed four times two mins 20-m over-ground shuttle running bouts at 3.3 m*s(-1) alternated by three mins rest. The first running bout was unloaded and the other three bouts were under randomised loaded conditions (1%, 3% and 5% additional loading of the individual body mass). 3D motion cameras and force plates recorded kinematic and kinetic data at the midpoint of each 20-m shuttle. Friedman-test for repeated measures and linear mixed effect model analysis were used to determine differences between the loading conditions (alpha = 0.05). Increased peak vertical ground reaction force (2.7 N/kg to 2.74 N/kg), ground contact time (0.20 s to 0.21 s) and decreased step length (1.49 m to 1.45 m) were found with additional 5 % body mass loading compared to unloaded running (0.001 > p < 0.007). Marginally more knee flexion and hip extension and less plantarflexion was seen with higher loading. Differences in the assessed parameters were present between each loading condition but accompanied by subject variability. Further studies, also examining long term effects, should be conducted to further inform use of this training tool.
KW - Kinematic
KW - Kinetic
KW - Weighted running
KW - External loading
KW - 3D motion
KW - capture
Y1 - 2022
U6 - https://doi.org/10.1016/j.jbiomech.2021.110903
SN - 0021-9290
SN - 1873-2380
VL - 130
PB - Elsevier Science
CY - New York, NY [u.a.]
ER -