@article{HelmPrieskeMuehlbaueretal.2020, author = {Helm, Norman and Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Retzlaff, Matthias and Granacher, Urs}, title = {Associations between trunk muscle strength and judo-specific pulling performances in judo athletes}, series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, volume = {34}, journal = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, number = {1}, publisher = {Thieme}, address = {Stuttgart}, issn = {0932-0555}, doi = {10.1055/a-0677-9608}, pages = {18 -- 27}, year = {2020}, abstract = {Background: Good trunk stability is an important prerequisite for the mobility of the upper and lower limbs during sport-specific movements. Therefore, trunk muscle strength may represent an important performance determinant for judo-specific movements. This study aimed at evaluating statistical correlations between trunk muscle strength and kinetic parameters during judo-specific pulling movements in judo players. Method: Twenty-one male sub-elite judo players aged 22 +/- 4 years with a mean training volume of 15 +/- 4 hours per week participated in this study. Peak isokinetic torque (PIT) of the trunk flexors (PITFlex), extensors (PITEx) and rotators (PITRot) was tested using an isokinetic dynamometer (IsoMed 2000). In addition, two kinetic parameters (mechanical work [W], maximal force [F-max]) were analysed using the judo-specific measurement and information system JERGo (c). For this purpose, athletes were asked to do their judo-specific pulling movements while standing and with a dynamic change of position (i.e. Morote-seoi-nage). Results: Regarding pulling movements while standing, significant correlations (0.62 <= r(P) <= 0.72) were found between isokinetic tests (PITFlex, PITEx, PITRot) and mechanical work during judo-specific movement. Further, significant correlations (0.59 <= r(P) <= 0.65) were detected between isokinetic tests (PITEx, PITRot) and judo-specific pulling movements (Fmax). Regarding pulling movements with a change of position, significant correlations (0.47 <= r(P) <= 0.88) were observed between isokinetics (PITFlex, PITEx, PITRot) and the kinetic pulling parameters (W, Fmax), irrespective of the examined arm. No significant differences in magnitude of correlation coefficients were found between PIT of the trunk flexors, extensors, and rotators and judo-specific movements. Further, the regression analysis indicated that PIT of the trunk extensors is the single best predictor for mechanical work during pulling movements while standing (46.9 \%). Trunk rotator PIT is the single best predictor for mechanical work during pulling movements with a change of position (69.4 \%). Conclusions: Findings from this study indicate that trunk muscle strength, particularly trunk rotator PIT is associated with kinetic pulling variables during pulling movements with a change of position. This implies that the development of trunk rotator strength could have an impact on pulling movements with a change of position (i.e. Morote-seoi-nage) in judo athletes.}, language = {de} } @article{HortobagyiLesinskiGaebleretal.2015, author = {Hortob{\´a}gyi, Tibor and Lesinski, Melanie and G{\"a}bler, Martijn and VanSwearingen, Jessie M. and Malatesta, Davide and Granacher, Urs}, title = {Effects of three types of exercise interventions on healthy old adults' gait speed}, series = {Sports medicine}, volume = {45}, journal = {Sports medicine}, publisher = {Springer}, address = {Berlin}, issn = {1179-2035}, doi = {10.1007/s40279-015-0371-2}, pages = {1627 -- 1643}, year = {2015}, abstract = {Background: Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear. Purpose: Our objective was to determine the effects of strength, power, coordination, and multimodal exercise training on healthy old adults' habitual and fast gait speed. Methods: We performed a computerized systematic literature search in PubMed and Web of Knowledge from January 1984 up to December 2014. Search terms included 'Resistance training', 'power training', 'coordination training', 'multimodal training', and 'gait speed (outcome term). Inclusion criteria were articles available in full text, publication period over past 30 years, human species, journal articles, clinical trials, randomized controlled trials, English as publication language, and subject age C65 years. The methodological quality of all eligible intervention studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. We computed weighted average standardized mean differences of the intervention-induced adaptations in gait speed using a random-effects model and tested for overall and individual intervention effects relative to no-exercise controls. Results: A total of 42 studies (mean PEDro score of 5.0 +/- 1.2) were included in the analyses (2495 healthy old adults; age 74.2 years [64.4-82.7]; body mass 69.9 +/- 4.9 kg, height 1.64 +/- 0.05 m, body mass index 26.4 +/- 1.9 kg/m(2), and gait speed 1.22 +/- 0.18 m/s). The search identified only one power training study, therefore the subsequent analyses focused only on the effects of resistance, coordination, and multimodal training on gait speed. The three types of intervention improved gait speed in the three experimental groups combined (n = 1297) by 0.10 m/s (+/- 0.12) or 8.4 \% (+/- 9.7), with a large effect size (ES) of 0.84. Resistance (24 studies; n = 613; 0.11 m/s; 9.3 \%; ES: 0.84), coordination (eight studies, n = 198; 0.09 m/s; 7.6 \%; ES: 0.76), and multimodal training (19 studies; n = 486; 0.09 m/s; 8.4 \%, ES: 0.86) increased gait speed statistically and similarly. Conclusions: Commonly used exercise interventions can functionally and clinically increase habitual and fast gait speed and help slow the loss of gait speed or delay its onset.}, language = {en} } @article{PrieskeDalagerLooksetal.2021, author = {Prieske, Olaf and Dalager, Tina and Looks, Vanessa and Golle, Kathleen and Granacher, Urs}, title = {Physical fitness and psycho-cognitive performance in the young and middle-aged workforce with primarily physical versus mental work demands}, series = {Journal of public health : from theory to practice : official organ of the Deutscher Verband f{\"u}r Gesundheitswissenschaften Public Health e.V. (DVGPH)}, volume = {29}, journal = {Journal of public health : from theory to practice : official organ of the Deutscher Verband f{\"u}r Gesundheitswissenschaften Public Health e.V. (DVGPH)}, number = {1}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {2198-1833}, doi = {10.1007/s10389-019-01099-9}, pages = {75 -- 84}, year = {2021}, abstract = {Aim The purpose of this study was to examine physical fitness and psycho-cognitive performance and their associations in young and middle-aged workers with primarily physical versus mental work demands. Subjects and methods Healthy young and middle-aged workers (73 men, age = 33 +/- 7 years; 75 women, age = 35 +/- 9 years) were recruited from German small-to-medium-sized enterprises (< 250 employees) and classified into groups with primarily mental (MD) or physical demands (PD) at work. Participants were tested for cardiorespiratory fitness, trunk flexor/extensor muscular endurance, handgrip strength, balance, leg muscle power, perceived stress, cognitive performance, and work ability. Results Ninety-four workers were allocated to the MD (53\% females) and 54 to the PD (46\% females) groups. The MD group showed significantly better balance, trunk extensor muscular endurance, and cognitive performance (p < 0.035, 0.35 <= d <= 0.55) and less stress compared with the PD group (p < 0.023, d = 0.38). Group-specific Spearman rank correlation analysis (r(S)) revealed significant small-to-medium-sized correlations between physical fitness and cognitive performance (- 0.205 <= r(S) <= 0.434) in the MD and PD groups. Significant small-to-medium-sized correlations were found for physical fitness and stress/work ability (0.211 <= r(S) <= 0.301) in the MD group only. Further, associations of trunk extensor muscular endurance and work ability were significantly higher in the MD group (r(S) = 0.240) compared with the PD group (r(S) = - 0.141; z = 2.16, p = 0.031). Conclusions MD workers showed better physical fitness measures (balance, trunk extensor muscular endurance) and cognitive performance and lower levels of perceived stress compared with PD workers. Small-to-medium-sized associations between physical fitness and psycho-cognitive performance measures indicate that gains in physical fitness may at least partly contribute to psycho-cognitive performance and/or vice versa, particularly in MD workers.}, language = {en} } @article{AhmadiHeratAlizadehetal.2021, author = {Ahmadi, Hamid and Herat, Nehara and Alizadeh, Shahab and Button, Duane C. and Granacher, Urs and Behm, David G.}, title = {Effect of an inverted seated position with upper arm blood flow restriction on measures of elbow flexors neuromuscular performance}, series = {PLOS ONE / Public Library of Science}, volume = {16}, journal = {PLOS ONE / Public Library of Science}, number = {5}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0245311}, pages = {19}, year = {2021}, abstract = {Purpose The objective of the investigation was to determine the concomitant effects of upper arm blood flow restriction (BFR) and inversion on elbow flexors neuromuscular responses. Methods Randomly allocated, 13 volunteers performed four conditions in a within-subject design: rest (control, 1-min upright position without BFR), control (1-min upright with BFR), 1-min inverted (without BFR), and 1-min inverted with BFR. Evoked and voluntary contractile properties, before, during and after a 30-s maximum voluntary contraction (MVC) exercise intervention were examined as well as pain scale. Results Inversion induced significant pre-exercise intervention decreases in elbow flexors MVC (21.1\%, Z2p = 0.48, p = 0.02) and resting evoked twitch forces (29.4\%, Z2p = 0.34, p = 0.03). The 30-s MVC induced significantly greater pre- to post-test decreases in potentiated twitch force (Z2p = 0.61, p = 0.0009) during inversion (75\%) than upright (65.3\%) conditions. Overall, BFR decreased MVC force 4.8\% (Z2p = 0.37, p = 0.05). For upright position, BFR induced 21.0\% reductions in M-wave amplitude (Z2p = 0.44, p = 0.04). There were no significant differences for electromyographic activity or voluntary activation as measured with the interpolated twitch technique. For all conditions, there was a significant increase in pain scale between the 40-60 s intervals and post-30-s MVC (upright< inversion, and without BFR< BFR). Conclusion The concomitant application of inversion with elbow flexors BFR only amplified neuromuscular performance impairments to a small degree. Individuals who execute forceful contractions when inverted or with BFR should be cognizant that force output may be impaired.}, language = {en} } @article{GebelLehmannGranacher2020, author = {Gebel, Arnd and Lehmann, Tim and Granacher, Urs}, title = {Balance task difficulty affects postural sway and cortical activity in healthy adolescents}, series = {Experimental brain research}, volume = {238}, journal = {Experimental brain research}, number = {5}, publisher = {Springer}, address = {New York}, issn = {0014-4819}, doi = {10.1007/s00221-020-05810-1}, pages = {1323 -- 1333}, year = {2020}, abstract = {Electroencephalographic (EEG) research indicates changes in adults' low frequency bands of frontoparietal brain areas executing different balance tasks with increasing postural demands. However, this issue is unsolved for adolescents when performing the same balance task with increasing difficulty. Therefore, we examined the effects of a progressively increasing balance task difficulty on balance performance and brain activity in adolescents. Thirteen healthy adolescents aged 16-17 year performed tests in bipedal upright stance on a balance board with six progressively increasing levels of task difficulty. Postural sway and cortical activity were recorded simultaneously using a pressure sensitive measuring system and EEG. The power spectrum was analyzed for theta (4-7 Hz) and alpha-2 (10-12 Hz) frequency bands in pre-defined frontal, central, and parietal clusters of electrocortical sources. Repeated measures analysis of variance (rmANOVA) showed a significant main effect of task difficulty for postural sway (p < 0.001; d = 6.36). Concomitantly, the power spectrum changed in frontal, bilateral central, and bilateral parietal clusters. RmANOVAs revealed significant main effects of task difficulty for theta band power in the frontal (p < 0.001, d = 1.80) and both central clusters (left: p < 0.001, d = 1.49; right: p < 0.001, d = 1.42) as well as for alpha-2 band power in both parietal clusters (left: p < 0.001, d = 1.39; right: p < 0.001, d = 1.05) and in the central right cluster (p = 0.005, d = 0.92). Increases in theta band power (frontal, central) and decreases in alpha-2 power (central, parietal) with increasing balance task difficulty may reflect increased attentional processes and/or error monitoring as well as increased sensory information processing due to increasing postural demands. In general, our findings are mostly in agreement with studies conducted in adults. Similar to adult studies, our data with adolescents indicated the involvement of frontoparietal brain areas in the regulation of postural control. In addition, we detected that activity of selected brain areas (e.g., bilateral central) changed with increasing postural demands.}, language = {en} } @article{AzadianMajlesiJafarnezhadgeroetal.2020, author = {Azadian, Elaheh and Majlesi, Mahdi and Jafarnezhadgero, Amir Ali and Granacher, Urs}, title = {The impact of hearing loss on three-dimensional lower limb joint torques during walking in prepubertal boys}, series = {Journal of bodywork and movement therapies}, volume = {24}, journal = {Journal of bodywork and movement therapies}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1360-8592}, doi = {10.1016/j.jbmt.2019.10.013}, pages = {123 -- 129}, year = {2020}, abstract = {Introduction: In children, the impact of hearing loss on biomechanical gait parameters is not well understood. Thus, the objectives of this study were to examine three-dimensional lower limb joint torques in deaf compared to age-matched healthy (hearing) children while walking at preferred gait speed. Methods: Thirty prepubertal boys aged 8-14 were enrolled in this study and divided into a group with hearing loss (deaf group) and an age-matched healthy control. Three-dimensional joint torques were analyzed during barefoot walking at preferred speed using Kistler force plates and a Vicon motion capture system. Results: Findings revealed that boys with hearing loss showed lower joint torques in ankle evertors, knee flexors, abductors and internal rotators as well as in hip internal rotators in both, the dominant and non-dominant lower limbs (all p < 0.05; d = 1.23-7.00; 14-79\%). Further, in the dominant limb, larger peak ankle dorsiflexor (p < 0.001; d = 1.83; 129\%), knee adductor (p < 0.001; d = 3.20; 800\%), and hip adductor torques (p < 0.001; d = 2.62; 350\%) were found in deaf participants compared with controls. Conclusion: The observed altered lower limb torques during walking are indicative of unstable gait in children with hearing loss. More research is needed to elucidate whether physical training (e.g., balance and/or gait training) has the potential to improve walking performance in this patient group. (C) 2019 Elsevier Ltd. All rights reserved.}, language = {en} } @article{JafarnezhadgeroFatollahiGranacher2022, author = {Jafarnezhadgero, Amir Ali and Fatollahi, Amir and Granacher, Urs}, title = {Eight weeks of exercising on sand has positive effects on biomechanics of walking and muscle activities in individuals with pronated feet}, series = {Sports : open access journal}, volume = {10}, journal = {Sports : open access journal}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2075-4663}, doi = {10.3390/sports10050070}, pages = {16}, year = {2022}, abstract = {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.}, language = {en} } @article{WerfelliHammamiSelmietal.2021, author = {Werfelli, Hanen and Hammami, Raouf and Selmi, Mohamed Amine and Selmi, Walid and Gabrilo, Goran and Clark, Cain C. T. and Duncan, Michael and Sekulic, Damir and Granacher, Urs and Rebai, Haithem}, title = {Acute Effects of Different Plyometric and Strength Exercises on Balance Performance in Youth Weightlifters}, series = {Frontiers in Physiology}, volume = {12}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2021.716981}, pages = {9}, year = {2021}, abstract = {Background: High-intensity muscle actions have the potential to temporarily improve the performance which has been denoted as postactivation performance enhancement. Objectives: This study determined the acute effects of different stretch-shortening (fast vs. low) and strength (dynamic vs. isometric) exercises executed during one training session on subsequent balance performance in youth weightlifters. Materials and Methods: Sixteen male and female young weightlifters, aged 11.3±0.6years, performed four strength exercise conditions in randomized order, including dynamic strength (DYN; 3 sets of 3 repetitions of 10 RM) and isometric strength exercises (ISOM; 3 sets of maintaining 3s of 10 RM of back-squat), as well as fast (FSSC; 3 sets of 3 repetitions of 20-cm drop-jumps) and slow (SSSC; 3 sets of 3 hurdle jumps over a 20-cm obstacle) stretch-shortening cycle protocols. Balance performance was tested before and after each of the four exercise conditions in bipedal stance on an unstable surface (i.e., BOSU ball with flat side facing up) using two dependent variables, i.e., center of pressure surface area (CoP SA) and velocity (CoP V). Results: There was a significant effect of time on CoP SA and CoP V [F(1,60)=54.37, d=1.88, p<0.0001; F(1,60)=9.07, d=0.77, p=0.003]. In addition, a statistically significant effect of condition on CoP SA and CoP V [F(3,60)=11.81, d=1.53, p<0.0001; F(3,60)=7.36, d=1.21, p=0.0003] was observed. Statistically significant condition-by-time interactions were found for the balance parameters CoP SA (p<0.003, d=0.54) and CoP V (p<0.002, d=0.70). Specific to contrast analysis, all specified hypotheses were tested and demonstrated that FSSC yielded significantly greater improvements than all other conditions in CoP SA and CoP V [p<0.0001 (d=1.55); p=0.0004 (d=1.19), respectively]. In addition, FSSC yielded significantly greater improvements compared with the two conditions for both balance parameters [p<0.0001 (d=2.03); p<0.0001 (d=1.45)]. Conclusion: Fast stretch-shortening cycle exercises appear to be more effective to improve short-term balance performance in young weightlifters. Due to the importance of balance for overall competitive achievement in weightlifting, it is recommended that young weightlifters implement dynamic plyometric exercises in the fast stretch-shortening cycle during the warm-up to improve their balance performance.}, language = {en} } @article{KasmiZouhalHammamietal.2021, author = {Kasmi, Sofien and Zouhal, Hassane and Hammami, Raouf and Clark, Cain Craig Truman and Hackney, Anthony C. and Hammami, Amri and Chtara, Moktar and Chortane, Sabri Gaied and Ben Salah, Fatma Zohra and Granacher, Urs and Ben Ounis, Omar}, title = {The Effects of Eccentric and Plyometric Training Programs and Their Combination on Stability and the Functional Performance in the Post-ACL-Surgical Rehabilitation Period of Elite Female Athletes}, series = {Frontiers in physiology}, volume = {12}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne, Schweiz}, issn = {1664-042X}, doi = {10.3389/fphys.2021.688385}, pages = {1 -- 11}, year = {2021}, abstract = {Background: The standard method to treat physically active patients with anterior cruciate ligament (ACL) rupture is ligament reconstruction surgery. The rehabilitation training program is very important to improve functional performance in recreational athletes following ACL reconstruction. Objectives: The aims of this study were to compare the effects of three different training programs, eccentric training (ECC), plyometric training (PLYO), or combined eccentric and plyometric training (COMB), on dynamic balance (Y-BAL), the Lysholm Knee Scale (LKS), the return to sport index (RSI), and the leg symmetry index (LSI) for the single leg hop test for distance in elite female athletes after ACL surgery. Materials and Methods: Fourteen weeks after rehabilitation from surgery, 40 elite female athletes (20.3 ± 3.2 years), who had undergone an ACL reconstruction, participated in a short-term (6 weeks; two times a week) training study. All participants received the same rehabilitation protocol prior to the training study. Athletes were randomly assigned to three experimental groups, ECC (n = 10), PLYO (n = 10), and COMB (n = 10), and to a control group (CON: n = 10). Testing was conducted before and after the 6-week training programs and included the Y-BAL, LKS, and RSI. LSI was assessed after the 6-week training programs only. Results: Adherence rate was 100\% across all groups and no training or test-related injuries were reported. No significant between-group baseline differences (pre-6-week training) were observed for any of the parameters. Significant group-by-time interactions were found for Y-BAL (p < 0.001, ES = 1.73), LKS (p < 0.001, ES = 0.76), and RSI (p < 0.001, ES = 1.39). Contrast analysis demonstrated that COMB yielded significantly greater improvements in Y-BAL, LKS, and RSI (all p < 0.001), in addition to significantly better performances in LSI (all p < 0.001), than CON, PLYO, and ECC, respectively. Conclusion: In conclusion, combined (eccentric/plyometric) training seems to represent the most effective training method as it exerts positive effects on both stability and functional performance in the post-ACL-surgical rehabilitation period of elite female athletes.}, language = {en} } @article{SariatiZouhalHammamietal.2021, author = {Sariati, Dorsaf and Zouhal, Hassane and Hammami, Raouf and Clark, Cain Craig Truman and Nebigh, Ammar and Chtara, Moktar and Hackney, Anthony C. and Souissi, Nizar and Granacher, Urs and Ben Ounis, Omar}, title = {Association Between Mental Imagery and Change of Direction Performance in Young Elite Soccer Players of Different Maturity Status}, series = {Frontiers in Psychology}, volume = {12}, journal = {Frontiers in Psychology}, publisher = {Frontiers Research Foundation}, address = {Lausanne, Schweiz}, issn = {1664-1078}, doi = {10.3389/fpsyg.2021.665508}, pages = {1 -- 9}, year = {2021}, abstract = {Previous studies have not considered the potential influence of maturity status on the relationship between mental imagery and change of direction (CoD) speed in youth soccer. Accordingly, this cross-sectional study examined the association between mental imagery and CoD performance in young elite soccer players of different maturity status. Forty young male soccer players, aged 10-17 years, were assigned into two groups according to their predicted age at peak height velocity (PHV) (Pre-PHV; n = 20 and Post-PHV; n = 20). Participants were evaluated on soccer-specific tests of CoD with (CoDBall-15m) and without (CoD-15m) the ball. Participants completed the movement imagery questionnaire (MIQ) with the three- dimensional structure, internal visual imagery (IVI), external visual imagery (EVI), as well as kinesthetic imagery (KI). The Post-PHV players achieved significantly better results than Pre-PHV in EVI (ES = 1.58, large; p < 0.001), CoD-15m (ES = 2.09, very large; p < 0.001) and CoDBall-15m (ES = 1.60, large; p < 0.001). Correlations were significantly different between maturity groups, where, for the pre-PHV group, a negative very large correlation was observed between CoDBall-15m and KI (r = -0.73, p = 0.001). For the post-PHV group, large negative correlations were observed between CoD-15m and IVI (r = -0.55, p = 0.011), EVI (r = -062, p = 0.003), and KI (r = -0.52, p = 0.020). A large negative correlation of CoDBall-15m with EVI (r = -0.55, p = 0.012) and very large correlation with KI (r = -0.79, p = 0.001) were also observed. This study provides evidence of the theoretical and practical use for the CoD tasks stimulus with imagery. We recommend that sport psychology specialists, coaches, and athletes integrated imagery for CoD tasks in pre-pubertal soccer players to further improve CoD related performance.}, language = {en} }