@article{PrieskeDempsLesinskietal.2017, author = {Prieske, Olaf and Demps, Marie and Lesinski, Melanie and Granacher, Urs}, title = {Combined Effects of Fatigue and Surface Instability on Jump Biomechanics in Elite Athletes}, series = {International journal of sports medicine}, volume = {38}, journal = {International journal of sports medicine}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0043-111894}, pages = {781 -- 790}, year = {2017}, abstract = {The present study aimed to examine the effects of fatigue and surface instability on kinetic and kinematic jump performance measures. Ten female and 10 male elite volleyball players (18 +/- 2 years) performed repetitive vertical double-leg box jumps until failure. Pre and post fatigue, jump height/performance index, ground reaction force and knee flexion/valgus angles were assessed during drop and countermovement jumps on stable and unstable surfaces. Fatigue, surface condition, and sex resulted in significantly lower drop jump performance and ground reaction force (p0.031, 1.1d3.5). Additionally, drop jump knee flexion angles were significantly lower following fatigue (p=0.006, d=1.5). A significant fatiguexsurfacexsex interaction (p=0.020, d=1.2) revealed fatigue-related decrements in drop jump peak knee flexion angles under unstable conditions and in men only. Knee valgus angles were higher on unstable compared to stable surfaces during drop jumps and in females compared to males during drop and countermovement jumps (p0.054, 1.0d1.1). Significant surfacexsex interactions during countermovement jumps (p=0.002, d=1.9) indicated that knee valgus angles at onset of ground contact were significantly lower on unstable compared to stable surfaces in males but higher in females. Our findings revealed that fatigue and surface instability resulted in sex-specific knee motion strategies during jumping in elite volleyball players.}, language = {en} } @misc{LesinskiMuehlbauerGranacher2017, author = {Lesinski, Melanie and M{\"u}hlbauer, Thomas and Granacher, Urs}, title = {Concurrent validity of the Gyko inertial sensor system for the assessment of vertical jump height in female sub-elite youth soccer players}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-400967}, pages = {9}, year = {2017}, abstract = {Background: The aim of the present study was to verify concurrent validity of the Gyko inertial sensor system for the assessment of vertical jump height. - Methods: Nineteen female sub-elite youth soccer players (mean age: 14.7 ± 0.6 years) performed three trials of countermovement (CMJ) and squat jumps (SJ), respectively. Maximal vertical jump height was simultaneously quantified with the Gyko system, a Kistler force-plate (i.e., gold standard), and another criterion device that is frequently used in the field, the Optojump system. - Results: Compared to the force-plate, the Gyko system determined significant systematic bias for mean CMJ (-0.66 cm, p < 0.01, d = 1.41) and mean SJ (-0.91 cm, p < 0.01, d = 1.69) height. Random bias was ± 3.2 cm for CMJ and ± 4.0 cm for SJ height and intraclass correlation coefficients (ICCs) were "excellent" (ICC = 0.87 for CMJ and 0.81 for SJ). Compared to the Optojump device, the Gyko system detected a significant systematic bias for mean CMJ (0.55 cm, p < 0.05, d = 0.94) but not for mean SJ (0.39 cm) height. Random bias was ± 3.3 cm for CMJ and ± 4.2 cm for SJ height and ICC values were "excellent" (ICC = 0.86 for CMJ and 0.82 for SJ). - Conclusion: Consequently, apparatus specific regression equations were provided to estimate true vertical jump height for the Kistler force-plate and the Optojump device from Gyko-derived data. Our findings indicate that the Gyko system cannot be used interchangeably with a Kistler force-plate and the Optojump device in trained individuals. It is suggested that practitioners apply the correction equations to estimate vertical jump height for the force-plate and the Optojump system from Gyko-derived data.}, language = {en} } @misc{LesinskiHortobagyiMuehlbaueretal.2015, author = {Lesinski, Melanie and Hortobagyi, Tibor and M{\"u}hlbauer, Thomas and Gollhofer, Albert and Granacher, Urs}, title = {Dose-Response Relationships of Balance Training in Healthy Young Adults: A Systematic Review and Meta-Analysis}, series = {Sports medicine}, volume = {45}, journal = {Sports medicine}, number = {4}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-014-0284-5}, pages = {557 -- 576}, year = {2015}, abstract = {Background Balance training (BT) has been used for the promotion of balance and sports-related skills as well as for prevention and rehabilitation of lower extremity sport injuries. However, evidence-based dose-response relationships in BT parameters have not yet been established. Objective The objective of this systematic literature review and meta-analysis was to determine dose-response relationships in BT parameters that lead to improvements in balance in young healthy adults with different training status. Data Sources A computerized systematic literature search was performed in the electronic databases PubMed, Web of Knowledge, and SPORTDiscus from January 1984 up to May 2014 to capture all articles related to BT in young healthy adults. Study Eligibility Criteria A systematic approach was used to evaluate the 596 articles identified for initial review. Only randomized controlled studies were included if they investigated BT in young healthy adults (16-40 years) and tested at least one behavioral balance performance outcome. In total, 25 studies met the inclusion criteria for review. Study Appraisal and Synthesis Methods Studies were evaluated using the physiotherapy evidence database (PEDro) scale. Within-subject effect sizes (ESdw) and between-subject effect sizes (ESdb) were calculated. The included studies were coded for the following criteria: training status (elite athletes, sub-elite athletes, recreational athletes, untrained subjects), training modalities (training period, frequency, volume, etc.), and balance outcome (test for the assessment of steady-state, proactive, and reactive balance). Results Mean ESdb demonstrated that BT is an effective means to improve steady-state (ESdb = 0.73) and proactive balance (ESdb = 0.92) in healthy young adults. Studies including elite athletes showed the largest effects (ESdb = 1.29) on measures of steady-state balance as compared with studies analyzing sub-elite athletes (ESdb = 0.32), recreational athletes (ESdb = 0.69), and untrained subjects (ESdb = 0.82). Our analyses regarding dose-response relationships in BT revealed that a training period of 11-12 weeks (ESdb = 1.09), a training frequency of three (mean ESdb = 0.72) or six (single ESdb = 1.84) sessions per week, at least 16-19 training sessions in total (ESdb = 1.12), a duration of 11-15 min for a single training session (ESdb = 1.11), four exercises per training session (ESdb = 1.29), two sets per exercise (ESdb = 1.63), and a duration of 21-40 s for a single BT exercise (ESdb = 1.06) is most effective in improving measures of steady-state balance. Due to a small number of studies, dose-response relationships of BT for measures of proactive and reactive balance could not be qualified. Limitations The present findings must be interpreted with caution because it is difficult to separate the impact of a single training modality (e.g., training frequency) from that of the others. Moreover, the quality of the included studies was rather limited, with a mean PEDro score of 5. Conclusions Our detailed analyses revealed effective BT parameters for the improvement of steady-state balance. Thus, practitioners and coaches are advised to consult the identified dose-response relationships of this systematic literature review and meta-analysis to implement effective BT protocols in clinical and sports-related contexts. However, further research of high methodological quality is needed to (1) determine dose-response relationships of BT for measures of proactive and reactive balance, (2) define effective sequencing protocols in BT (e.g., BT before or after a regular training session), (3) discern the effects of detraining, and (4) develop a feasible and effective method to regulate training intensity in BT.}, language = {en} } @misc{LesinskiHortobagyiMuehlbaueretal.2016, author = {Lesinski, Melanie and Hortobagyi, Tibor and M{\"u}hlbauer, Thomas and Gollhofer, Albert and Granacher, Urs}, title = {Dose-Response Relationships of Balance Training in Healthy Young Adults: A Systematic Review and Meta-Analysis (vol 45, pg 557, 2015)}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-016-0499-8}, pages = {455 -- 455}, year = {2016}, language = {en} } @misc{GebelLesinskiBehmetal.2018, author = {Gebel, Arnd and Lesinski, Melanie and Behm, David George and Granacher, Urs}, title = {Effects and dose-response relationship of balance training on balance performance in Youth}, series = {Sports medicine}, volume = {48}, journal = {Sports medicine}, number = {9}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-018-0926-0}, pages = {2067 -- 2089}, year = {2018}, abstract = {Background Effects and dose-response relationships of balance training on measures of balance are well-documented for healthy young and old adults. However, this has not been systematically studied in youth. Objectives The objectives of this systematic review and meta-analysis were to quantify effects of balance training (BT) on measures of static and dynamic balance in healthy children and adolescents. Additionally, dose-response relations for BT modalities (e.g. training period, frequency, volume) were quantified through the analysis of controlled trials. Data Sources A computerized systematic literature search was conducted in the electronic databases PubMed and Web of Science from January 1986 until June 2017 to identify articles related to BT in healthy trained and untrained children and adolescents. Study Eligibility Criteria A systematic approach was used to evaluate articles that examined the effects of BT on balance outcomes in youth. Controlled trials with pre- and post-measures were included if they examined healthy youth with a mean age of 6-19 years and assessed at least one measure of balance (i.e. static/dynamic steady-state balance, reactive balance, proactive balance) with behavioural (e.g. time during single-leg stance) or biomechanical (e.g. centre of pressure displacements during single-leg stance) test methods. Study Appraisal and Synthesis Methods The included studies were coded for the following criteria: training modalities (i.e. training period, frequency, volume), balance outcomes (i.e. static and dynamic balance) as well as chronological age, sex (male vs. female), training status (trained vs. untrained), setting (school vs. club), and testing method (biomechanical vs. physical fitness test). Weighted mean standardized mean differences (SMDwm) were calculated using a random-effects model to compute overall intervention effects relative to active and passive control groups. Between-study heterogeneity was assessed using I 2 and chi(2) statistics. A multivariate random effects meta-regression was computed to explain the influence of key training modalities (i.e. training period, training frequency, total number of training sessions, duration of training sessions, and total duration of training per week) on the effectiveness of BT on measures of balance performance. Further, subgroup univariate analyses were computed for each training modality. Additionally, dose-response relationships were characterized independently by interpreting the modality specific magnitude of effect sizes. Methodological quality of the included studies was rated with the help of the Physiotherapy Evidence Database (PEDro) Scale. Results Overall, our literature search revealed 198 hits of which 17 studies were eligible for inclusion in this systematic review and meta-analysis. Irrespective of age, sex, training status, sport discipline and training method, moderate to large BT-related effects were found for measures of static (SMDwm = 0.71) and dynamic (SMDwm = 1.03) balance in youth. However, our subgroup analyses did not reveal any statistically significant effects of the moderator variables age, sex, training status, setting and testing method on overall balance (i.e. aggregation of static and dynamic balance). BT-related effects in adolescents were moderate to large for measures of static (SMDwm = 0.61) and dynamic (SMDwm = 0.86) balance. With regard to the dose-response relationships, findings from the multivariate random effects meta-regression revealed that none of the examined training modalities predicted the effects of BT on balance performance in adolescents (R-2 = 0.00). In addition, results from univariate analysis have to be interpreted with caution because training modalities were computed as single factors irrespective of potential between-modality interactions. For training period, 12 weeks of training achieved the largest effect (SMDwm = 1.40). For training frequency, the largest effect was found for two sessions per week (SMDwm = 1.29). For total number of training sessions, the largest effect was observed for 24-36 sessions (SMDwm = 1.58). For the modality duration of a single training session, 4-15 min reached the largest effect (SMDwm = 1.03). Finally, for the modality training per week, a total duration of 31-60 min per week (SMDwm = 1.33) provided the largest effects on overall balance in adolescents. Methodological quality of the studies was rated as moderate with a median PEDro score of 6.0. Limitations Dose-response relationships were calculated independently for training modalities (i.e. modality specific) and not interdependently. Training intensity was not considered for the calculation of dose-response relationships because the included studies did not report this training modality. Further, the number of included studies allowed the characterization of dose-response relationships in adolescents for overall balance only. In addition, our analyses revealed a considerable between-study heterogeneity (I-2 = 66-83\%). The results of this meta-analysis have to be interpreted with caution due to their preliminary status. Conclusions BT is a highly effective means to improve balance performance with moderate to large effects on static and dynamic balance in healthy youth irrespective of age, sex, training status, setting and testing method. The examined training modalities did not have a moderating effect on balance performance in healthy adolescents. Thus, we conclude that an additional but so far unidentified training modality may have a major effect on balance performance that was not assessed in our analysis. Training intensity could be a promising candidate. However, future studies are needed to find appropriate methods to assess BT intensity.}, language = {en} } @misc{LesinskiPrieskeGranacher2016, author = {Lesinski, Melanie and Prieske, Olaf and Granacher, Urs}, title = {Effects and dose-response relationships of resistance training on physical performance in youth athletes: a systematic review and meta-analysis}, series = {British journal of sports medicine : the journal of sport and exercise medicine}, volume = {50}, journal = {British journal of sports medicine : the journal of sport and exercise medicine}, publisher = {BMJ Publishing Group}, address = {London}, issn = {0306-3674}, doi = {10.1136/bjsports-2015-095497}, pages = {781 -- 795}, year = {2016}, abstract = {Objectives To quantify age, sex, sport and training type-specific effects of resistance training on physical performance, and to characterise dose-response relationships of resistance training parameters that could maximise gains in physical performance in youth athletes. Design Systematic review and meta-analysis of intervention studies. Data sources Studies were identified by systematic literature search in the databases PubMed and Web of Science (1985-2015). Weighted mean standardised mean differences (SMDwm) were calculated using random-effects models. Eligibility criteria for selecting studies Only studies with an active control group were included if these investigated the effects of resistance training in youth athletes (6-18 years) and tested at least one physical performance measure. Results 43 studies met the inclusion criteria. Our analyses revealed moderate effects of resistance training on muscle strength and vertical jump performance (SMDwm 0.8-1.09), and small effects on linear sprint, agility and sport-specific performance (SMDwm 0.58-0.75). Effects were moderated by sex and resistance training type. Independently computed dose-response relationships for resistance training parameters revealed that a training period of >23 weeks, 5 sets/exercise, 6-8 repetitions/set, a training intensity of 80-89\% of 1 repetition maximum (RM), and 3-4 min rest between sets were most effective to improve muscle strength (SMDwm 2.09-3.40). Summary/conclusions Resistance training is an effective method to enhance muscle strength and jump performance in youth athletes, moderated by sex and resistance training type. Dose-response relationships for key training parameters indicate that youth coaches should primarily implement resistance training programmes with fewer repetitions and higher intensities to improve physical performance measures of youth athletes.}, language = {en} } @misc{LesinskiHortobagyiMuehlbaueretal.2016, author = {Lesinski, Melanie and Hortobagyi, Tibor and M{\"u}hlbauer, Thomas and Gollhofer, Albert and Granacher, Urs}, title = {Effects of Balance Training on Balance Performance in Healthy Older Adults: A Systematic Review and Meta-analysis (vol 45, pg 1721, 2015)}, series = {Sports medicine}, volume = {46}, journal = {Sports medicine}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-016-0500-6}, pages = {457 -- 457}, year = {2016}, language = {en} } @article{LesinskiPrieskeBordeetal.2018, author = {Lesinski, Melanie and Prieske, Olaf and Borde, Ron and Beurskens, Rainer and Granacher, Urs}, title = {Effects of Different Footwear Properties and Surface Instability on Neuromuscular Activity and Kinematics During Jumping}, series = {Journal of strength and conditioning research : the research journal of the NSCA}, volume = {32}, journal = {Journal of strength and conditioning research : the research journal of the NSCA}, number = {11}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1064-8011}, doi = {10.1519/JSC.0000000000002556}, pages = {3246 -- 3257}, year = {2018}, abstract = {The purpose of this study was to examine sex-specific effects of different footwear properties vs. barefoot condition during the performance of drop jumps (DJs) on stable and unstable surfaces on measures of jump performance, electromyographic (EMG) activity, and knee joint kinematics. Drop jump performance, EMG activity of lower-extremity muscles, as well as sagittal and frontal knee joint kinematics were tested in 28 healthy male (n = 14) and female (n = 14) physically active sports science students (23 6 2 years) during the performance of DJs on stable and unstable surfaces using different footwear properties (elastic vs. minimal shoes) vs. barefoot condition. Analysis revealed a significantly lower jump height and performance index (Delta 7-12\%; p < 0.001; 2.22 <= d = 2.90) during DJs on unstable compared with stable surfaces. This was accompanied by lower thigh/shank muscle activities (Delta 11-28\%; p < 0.05; 0.99 <= d = 2.16) and knee flexion angles (Delta 5-8\%; p < 0.05; 1.02 <= d = 2.09). Furthermore, knee valgus angles during DJs were significantly lower when wearing shoes compared with barefoot condition (Delta 22-32\%; p < 0.01; 1.38 <= d = 3.31). Sex-specific analyses indicated higher knee flexion angles in females compared with males during DJs, irrespective of the examined surface and footwear conditions (Delta 29\%; p < 0.05; d = 0.92). Finally, hardly any significant footwear-surface interactions were detected. Our findings revealed that surface instability had an impact on DJ performance, thigh/shank muscle activity, and knee joint kinematics. In addition, the single factors "footwear" and "sex" modulated knee joint kinematics during DJs. However, hardly any significant interaction effects were found. Thus, additional footwear-related effects can be neglected when performing DJs during training on different surfaces.}, language = {en} } @article{LesinskiPrieskeBeurskensetal.2017, author = {Lesinski, Melanie and Prieske, Olaf and Beurskens, Rainer and Behm, David George and Granacher, Urs}, title = {Effects of drop height and surface instability on neuromuscular activation during drop jumps}, series = {Scandinavian journal of medicine \& science in sports}, volume = {27}, journal = {Scandinavian journal of medicine \& science in sports}, publisher = {Wiley}, address = {Hoboken}, issn = {0905-7188}, doi = {10.1111/sms.12732}, pages = {1090 -- 1098}, year = {2017}, abstract = {The purpose of this study was to examine whether drop height-induced changes in leg muscle activity during drop jumps (DJ) are additionally modulated by surface condition. Twenty-four healthy participants (23.7 +/- 1.8years) performed DJs on a force plate on stable, unstable, and highly unstable surfaces using different drop heights (i.e., 20cm, 40cm, 60cm). Electromyographic (EMG) activity of soleus (SOL), gastrocnemius (GM), tibialis anterior (TA) muscles and coactivation of TA/SOL and TA/GM were analyzed for time intervals 100ms prior to ground contact (preactivation) and 30-60ms after ground contact [short latency response (SLR)]. Increasing drop heights resulted in progressively increased SOL and GM activity during preactivation and SLR (P<0.01; 1.01 d 5.34) while TA/SOL coactivation decreased (P<0.05; 0.51 d 3.01). Increasing surface instability produced decreased activities during preactivation (GM) and SLR (GM, SOL) (P<0.05; 1.36 d 4.30). Coactivation increased during SLR (P<0.05; 1.50 d 2.58). A significant drop heightxsurface interaction was observed for SOL during SLR. Lower SOL activity was found on unstable compared to stable surfaces for drop heights 40cm (P<0.05; 1.25 d 2.12). Findings revealed that instability-related changes in activity of selected leg muscles are minimally affected by drop height.}, language = {en} } @article{LesinskiPrieskeBeurskensetal.2017, author = {Lesinski, Melanie and Prieske, Olaf and Beurskens, Rainer and Behm, David George and Granacher, Urs}, title = {Effects of Drop-height and Surface Instability on Jump Performance and Knee Kinematics}, series = {International journal of sports medicine}, volume = {39}, journal = {International journal of sports medicine}, number = {1}, publisher = {Thieme}, address = {Stuttgart}, issn = {0172-4622}, doi = {10.1055/s-0043-117610}, pages = {50 -- 57}, year = {2017}, abstract = {The purpose of this study was to examine the combined effects of drop-height and surface condition on drop jump (DJ) performance and knee joint kinematics. DJ performance, sagittal and frontal plane knee joint kinematics were measured in jump experienced young male and female adults during DJs on stable, unstable and highly unstable surfaces using different drop-heights (20, 40, 60 cm). Findings revealed impaired DJ performance (Δ5-16\%; p<0.05; 1.43≤d≤2.82), reduced knee valgus motion (Δ33-52\%; p<0.001; 2.70≤d≤3.59), and larger maximum knee flexion angles (Δ13-19\%; p<0.01; 1.74≤d≤1.75) when using higher (60 cm) compared to lower drop-heights (≤40 cm). Further, lower knee flexion angles and velocity were found (Δ8-16\%; p<0.01; 1.49≤d≤2.38) with increasing surface instability. When performing DJs from high (60 cm) compared to moderate drop-heights (40 cm) on highly unstable surfaces, higher knee flexion velocity and maximum knee valgus angles were found (Δ15-19\%; p<0.01; 1.50≤d≤1.53). No significant main and/or interaction effects were observed for the factor sex. In conclusion, knee motion strategies were modified by the factors 'drop-height' and/or 'surface instability'. The combination of high drop-heights (>40 cm) together with highly unstable surfaces should be used cautiously during plyometrics because this may increase the risk of injury due to higher knee valgus stress.}, language = {en} }