@misc{HortobagyiLesinskiFernandez‐del‐Olmoetal.2015, author = {Hortob{\´a}gyi, Tibor and Lesinski, Melanie and Fernandez-del-Olmo, Miguel and Granacher, Urs}, title = {Small and inconsistent effects of whole body vibration on athletic performance}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {627}, issn = {1866-8364}, doi = {10.25932/publishup-43199}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431993}, pages = {23}, year = {2015}, abstract = {Purpose We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Methods Systematic literature review and meta-analysis. Results Whole body vibration combined with exercise had an overall 0.3 \% acute effect on maximal voluntary leg force (-6.4 \%, effect size = -0.43, 1 study), leg power (4.7 \%, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 \%, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 \%, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 \% chronic effect on maximal voluntary leg force (14.6 \%, weighted mean effect size = 0.44, 5 studies), leg power (10.7 \%, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 \%, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 \%, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Conclusions Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance.}, language = {en} } @misc{HortobagyiLesinskiFernandezdelOlmoetal.2015, author = {Hortobagyi, Tibor and Lesinski, Melanie and Fernandez-del-Olmo, Miguel and Granacher, Urs}, title = {Small and inconsistent effects of whole body vibration on athletic performance: a systematic review and meta-analysis}, series = {European journal of applied physiology}, volume = {115}, journal = {European journal of applied physiology}, number = {8}, publisher = {Springer}, address = {New York}, issn = {1439-6319}, doi = {10.1007/s00421-015-3194-9}, pages = {1605 -- 1625}, year = {2015}, abstract = {We quantified the acute and chronic effects of whole body vibration on athletic performance or its proxy measures in competitive and/or elite athletes. Systematic literature review and meta-analysis. Whole body vibration combined with exercise had an overall 0.3 \% acute effect on maximal voluntary leg force (-6.4 \%, effect size = -0.43, 1 study), leg power (4.7 \%, weighted mean effect size = 0.30, 6 studies), flexibility (4.6 \%, effect size = -0.12 to 0.22, 2 studies), and athletic performance (-1.9 \%, weighted mean effect size = 0.26, 6 studies) in 191 (103 male, 88 female) athletes representing eight sports (overall effect size = 0.28). Whole body vibration combined with exercise had an overall 10.2 \% chronic effect on maximal voluntary leg force (14.6 \%, weighted mean effect size = 0.44, 5 studies), leg power (10.7 \%, weighted mean effect size = 0.42, 9 studies), flexibility (16.5 \%, effect size = 0.57 to 0.61, 2 studies), and athletic performance (-1.2 \%, weighted mean effect size = 0.45, 5 studies) in 437 (169 male, 268 female) athletes (overall effect size = 0.44). Whole body vibration has small and inconsistent acute and chronic effects on athletic performance in competitive and/or elite athletes. These findings lead to the hypothesis that neuromuscular adaptive processes following whole body vibration are not specific enough to enhance athletic performance. Thus, other types of exercise programs (e.g., resistance training) are recommended if the goal is to improve athletic performance.}, language = {en} } @article{LesinskiHerzSchmelcheretal.2020, author = {Lesinski, Melanie and Herz, Michael and Schmelcher, Alina and Granacher, Urs}, title = {Effects of resistance training on physical fitness in healthy children and adolescents}, series = {Sports medicine}, volume = {50}, journal = {Sports medicine}, number = {11}, publisher = {Springer}, address = {Northcote}, issn = {0112-1642}, doi = {10.1007/s40279-020-01327-3}, pages = {1901 -- 1928}, year = {2020}, abstract = {Background Over the past decades, an exponential growth has occurred with regards to the number of scientific publications including meta-analyses on youth resistance training (RT). Accordingly, it is timely to summarize findings from meta-analyses in the form of an umbrella review. Objectives To systematically review and summarise the findings of published meta-analyses that investigated the effects of RT on physical fitness in children and adolescents. Design Systematic umbrella review of meta-analyses. Data Sources Meta-analyses were identified using systematic literature searches in the databases PubMed, Web of Science, and Cochrane Library. Eligibility Criteria for Selecting Meta-analyses Meta-analyses that examined the effects of RT on physical fitness (e.g., muscle strength, muscle power) in healthy youth (<= 18 years). Results Fourteen meta-analyses were included in this umbrella review. Eleven of these meta-analyses reported between-subject effect sizes which are important to eliminate bias due to growth and maturation. RT produced medium-to-large effects on muscle strength, small-to-large effects on muscle power, small-to-medium effects on linear sprint, a medium effect on agility/change-of-direction speed, small-to-large effects on throwing performance, and a medium effect on sport-specific enhancement. There were few consistent moderating effects of maturation, age, sex, expertise level, or RT type on muscle strength and muscle power across the included meta-analyses. The analysed meta-analyses showed low-to-moderate methodological quality (AMSTAR2) as well as presented evidence of low-to-very low quality (GRADE). Conclusion This umbrella review proved the effectiveness of RT in youth on a high evidence level. The magnitude of effects varies according to the respective outcome measure and it appears to follow the principle of training specificity. Larger effect sizes were found for strength-related outcome measures. Future studies should consistently report data on participants' maturational status. More research is needed with prepubertal children and girls, irrespective of their maturational status.}, language = {en} } @article{LesinskiPrieskeHelmetal.2017, author = {Lesinski, Melanie and Prieske, Olaf and Helm, Norman and Granacher, Urs}, title = {Effects of Soccer Training on Anthropometry, Body Composition, and Physical Fitness during a Soccer Season in Female Elite Young Athletes: A Prospective Cohort Study}, series = {Frontiers in physiology}, volume = {8}, journal = {Frontiers in physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2017.01093}, pages = {13}, year = {2017}, abstract = {The objectives of this study were to (i) describe soccer training (e.g., volume, types), anthropometry, body composition, and physical fitness and (0 compute associations between soccer training data and relative changes of anthropometry, body composition, and physical fitness during a soccer season in female elite young athletes. Seasonal training (i.e., day-to-day training volume/types) as well as variations in anthropometry (e.g., body height/mass), body composition (e.g., lean body/fat mass), and physical fitness (e.g., muscle strength/power, speed, balance) were collected from 17 female elite young soccer players (15.3 +/- 0.5 years) over the training periods (i.e., preparation, competition, transition) of a soccer season that resulted in the German championship title in under-17 female soccer. Training volume/types, anthropometrics, body composition, and physical fitness significantly varied over a soccer season. During the two preparation periods, higher volumes in resistance and endurance training were performed (2.00 <= d <= 18.15; p < 0.05), while higher sprint and tactical training volumes were applied during the two competition periods (2.22 <= d <= 11.18; p < 0.05). Body height and lean body mass increased over the season (2.50 <= d <= 3.39; p < 0.01). In terms of physical fitness, significant performance improvements were found over the soccer season in measures of balance, endurance, and sport-specific performance (2.52 <= d <= 3.95; p < 0.05). In contrast, no statistically significant changes were observed for measures of muscle power/endurance, speed, and change-of-direction speed. Of note, variables of muscle strength (i.e., leg extensors) significantly decreased (d = 2.39: p < 0.01) over the entire season. Our period specific sub analyses revealed significant performance improvements during the first round of the season for measures of muscle power/endurance, and balance (0.89 <= d <= 4.01; p < 0.05). Moreover, change-of-direction speed significantly declined after the first round of the season, i.e., transition period (d = 2.83; p < 0.01). Additionally, significant medium-to-large associations were observed between training and anthropometrics/body composition/physical fitness (-0.541 <= r <= 0.505). Soccer training and/or growth/maturation contributed to significant variations in anthropometry, body composition, and physical fitness outcomes throughout the different training periods over the course of a soccer season in female elite young soccer players. However, changes in components of fitness were inconsistent (e.g., power, speed, strength). Thus, training volume and/or types should be carefully considered in order to develop power-, speed- or strength-related fitness measures more efficiently throughout the soccer season.}, language = {en} } @article{LesinskiMuehlbauerBueschetal.2013, author = {Lesinski, Melanie and M{\"u}hlbauer, Thomas and Buesch, Dirk and Granacher, Urs}, title = {Acute Effects of Postactivation Potentiation on Strength and Speed Performance in Athletes}, series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, volume = {27}, journal = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation}, number = {3}, publisher = {Thieme}, address = {Stuttgart}, issn = {0932-0555}, doi = {10.1055/s-0033-1335414}, pages = {147 -- 155}, year = {2013}, abstract = {Background: The contractile history of a muscle or a muscle group can result in an acute enhancement of subsequent muscle force output. This phenomenon is referred to as postactivation potentiation (PAP) and it was frequently substantiated in original research manuscripts, systematic literature reviews, and meta-analyses. However, there is a lack in the literature regarding precise dose-response relations. This literature review describes the main determinants of PAP effects and additionally presents the state of the art regarding the acute effects of PAP protocols on measures of strength, power, and speed in subelite and elite athletes of different sport disciplines. Furthermore, an attempt is made to demonstrate evidence-based information concerning the design of effective PAP protocols. Methods: Our literature search included the electronic databases Pubmed, SportDiscus, and Google Scholar (1995 - March 2013). In total, 23 studies met the inclusionary criteria for review. Results: Findings from our literature review indicate that various conditioning activities produce acute PAP effects in subelite and particularly elite athletes. More specifically, conditioning activities that are characterised by multiple sets, moderate to high intensities (60 - 84 \% of the one repetition maximum), and rest intervals of 7 - 10 min. following the conditioning activity have the potential to induce short-term improvements in muscle force output and sports performance. Conclusion: It is recommended that subelite and particularly elite athletes from strength, power, and speed disciplines apply specifically tailored conditioning activities during the acute preparation process for competition to induce performance enhancing PAP effects.}, language = {de} } @article{ThielePrieskeLesinskietal.2020, author = {Thiele, Dirk and Prieske, Olaf and Lesinski, Melanie and Granacher, Urs}, title = {Effects of Equal Volume Heavy-Resistance Strength Training Versus Strength Endurance Training on Physical Fitness and Sport-Specific Performance in Young Elite Female Rowers}, series = {Frontiers in Physiology}, volume = {11}, journal = {Frontiers in Physiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-042X}, doi = {10.3389/fphys.2020.00888}, pages = {12}, year = {2020}, abstract = {Strength training is an important means for performance development in young rowers. The purpose of this study was to examine the effects of a 9-week equal volume heavy-resistance strength training (HRST) versus strength endurance training (SET) in addition to regular rowing training on primary (e.g., maximal strength/power) and secondary outcomes (e.g., balance) in young rowers. Twenty-six female elite adolescent rowers were assigned to an HRST (n = 12; age: 13.2 ± 0.5 yrs; maturity-offset: +2.0 ± 0.5 yrs) or a SET group (n = 14; age: 13.1 ± 0.5 yrs; maturity-offset: +2.1 ± 0.5 yrs). HRST and SET comprised lower- (i.e., leg press/knee flexion/extension), upper-limbs (i.e., bench press/pull; lat-pull down), and complex exercises (i.e., rowing ergometer). HRST performed four sets with 12 repetitions per set at an intensity of 75-95\% of the one-repetition maximum (1-RM). SET conducted four sets with 30 repetitions per set at 50-60\% of the 1-RM. Training volume was matched for overall repetitions × intensity × training per week. Pre-post training, tests were performed for the assessment of primary [i.e., maximal strength (e.g., bench pull/knee flexion/extension 1-RM/isometric handgrip test), muscle power (e.g., medicine-ball push test, triple hop, drop jump, and countermovement jump), anaerobic endurance (400-m run), sport-specific performance (700-m rowing ergometer trial)] and secondary outcomes [dynamic balance (Y-balance test), change-of-direction (CoD) speed (multistage shuttle-run test)]. Adherence rate was >87\% and one athlete of each group dropped out. Overall, 24 athletes completed the study and no test or training-related injuries occurred. Significant group × time interactions were observed for maximal strength, muscle power, anaerobic endurance, CoD speed, and sport-specific performance (p ≤ 0.05; 0.45 ≤ d ≤ 1.11). Post hoc analyses indicated larger gains in maximal strength and muscle power following HRST (p ≤ 0.05; 1.81 ≤ d ≤ 3.58) compared with SET (p ≤ 0.05; 1.04 ≤ d ≤ 2.30). Furthermore, SET (p ≤ 0.01; d = 2.08) resulted in larger gains in sport-specific performance compared with HRST (p < 0.05; d = 1.3). Only HRST produced significant pre-post improvements for anaerobic endurance and CoD speed (p ≤ 0.05; 1.84 ≤ d ≤ 4.76). In conclusion, HRST in addition to regular rowing training was more effective than SET to improve selected measures of physical fitness (i.e., maximal strength, muscle power, anaerobic endurance, and CoD speed) and SET was more effective than HRST to enhance sport-specific performance gains in female elite young rowers.}, language = {en} } @article{ChaabeneLesinskiBehmetal.2020, author = {Chaabene, Helmi and Lesinski, Melanie and Behm, David George and Granacher, Urs}, title = {Performance- and healthrelated benefits of youth resistance training}, series = {Sports Orthopaedics and Traumatology}, volume = {36}, journal = {Sports Orthopaedics and Traumatology}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, pages = {10}, year = {2020}, abstract = {Performance- and healthrelated benefits of yoThere is ample evidence that youth resistance training (RT) is safe, joyful, and effective for different markers of performance (e.g., muscle strength, power, linear sprint speed) and health (e.g., injury prevention). Accordingly, the first aim of this narrative review is to present and discuss the relevance of muscle strength for youth physical development. The second purpose is to report evidence on the effectiveness of RT on muscular fitness (muscle strength, power, muscle endurance), on movement skill performance and injury prevention in youth. There is evidence that RT is effective in enhancing measures of muscle fitness in children and adolescents, irrespective of sex. Additionally, numerous studies indicate that RT has positive effects on fundamental movement skills (e.g., jumping, running, throwing) in youth regardless of age, maturity, training status, and sex. Further, irrespective of age, sex, and training status, regular exposure to RT (e.g., plyometric training) decreases the risk of sustaining injuries in youth. This implies that RT should be a meaningful element of youths' exercise programming. This has been acknowledged by global (e.g., World Health Organization) and national (e.g., National Strength and Conditioning Association) health- and performance-related organizations which is why they recommended to perform RT as an integral part of weekly exercise programs to promote muscular strength, fundamental movement skills, and to resist injuries in youth.uth resistance training}, language = {en} } @article{WallentaGranacherLesinskietal.2016, author = {Wallenta, Christopher and Granacher, Urs and Lesinski, Melanie and Schuenemann, C. and M{\"u}hlbauer, Thomas}, title = {Effects of Complex Versus Block Strength Training on the Athletic Performance of Elite Youth Soccer Players}, series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\~A}\ivention, Rehabilitation}, volume = {30}, journal = {Sportverletzung, Sportschaden : Grundlagen, Pr{\~A}\ivention, Rehabilitation}, publisher = {Thieme}, address = {Stuttgart}, issn = {0932-0555}, doi = {10.1055/s-0041-106949}, pages = {31 -- 37}, year = {2016}, abstract = {Hintergrund: Kraft und Schnelligkeit stellen bedeutsame leistungsdeterminierende Faktoren im Fußball dar. Durch Komplextraining (Kombination aus Kraft- und plyometrischen {\"U}bungen in einer Trainingseinheit) lassen sich Kraft- und Schnelligkeitswerte von Athleten steigern. Unklar ist jedoch, ob ein Komplextraining (KT) gegen{\"u}ber einem herk{\"o}mmlichen blockweisen Krafttraining (BT) zu gr{\"o}ßeren sportmotorischen Leistungssteigerungen f{\"u}hrt. Das Ziel der Studie war es, die Effekte von KT versus BT auf Variablen der Kraft, Schnelligkeit und Gewandtheit von Nachwuchsleistungsfußballern zu untersuchen. Methode: Zus{\"a}tzlich zum regul{\"a}ren Fußballtraining (ca. 6 × pro Woche, je 60 - 90 min.) f{\"u}hrten 18 m{\"a}nnliche Nachwuchsleistungsfußballer {\"u}ber sechs Wochen (2 × pro Woche, je 30 min.) entweder ein progressives KT (n = 10, Alter: 18,5 ± 2,2 Jahre) oder BT (n = 8, Alter: 18,1 ± 1,6 Jahre) durch. Vor und nach dem Training wurden Tests zur Erfassung der Kraft (Einer-Wiederholungs-Maximum [EWM] Kniebeuge), der Sprungkraft (Hockstrecksprung [HSS]), der Schnelligkeit (30-m-Sprint) und der Gewandtheit (T-Test) durchgef{\"u}hrt. Es wurden parameterfreie Verfahren zur Bestimmung von Unterschieden innerhalb (Wilcoxon-Test) und zwischen (Mann-Whitney-U-Test) den beiden Gruppen gerechnet. Ergebnisse: Sowohl KT als auch BT sind sichere (keine trainings- aber sechs spielbedingte Verletzungen) und geeignete (Trainingsteilnahme in KT und BT: \&\#8805; 80 \%) Trainingsmaßnahmen in Erg{\"a}nzung zum regul{\"a}ren Fußballtraining. Die statistische Analyse ergab signifikante Verbesserungen vom Pr{\"a}- zum Posttest f{\"u}r die KT-Gruppe im EWM (p = 0,043) und im HSS (p = 0,046) sowie f{\"u}r die BT-Gruppe in der Sprintzeit {\"u}ber 5 m (p = 0,039) und 10 m (p = 0,026). Zudem zeigten sich f{\"u}r beide Gruppen signifikante Verbesserungen im T-Test (KT: p = 0,046; BT: p = 0,027). Der Gruppenvergleich (KT vs. BT) {\"u}ber die Zeit (Post- minus Pr{\"a}test) offenbarte keine bedeutsamen Unterschiede. Schlussfolgerung: Sowohl sechsw{\"o}chiges KT als auch BT f{\"u}hrten zu signifikanten Verbesserungen sportmotorischer Leistungen bei Nachwuchsleistungsfußballern. Allerdings konnten keine zus{\"a}tzlich leistungssteigernden Effekte von KT im Vergleich zu BT ermittelt werden. In zuk{\"u}nftigen Studien sollte gepr{\"u}ft werden, ob die beobachteten testspezifischen Ver{\"a}nderungen, d. h. Verbesserung der Kraft/Sprungkraft in der KT-Gruppe und Verbesserung der Schnelligkeit in der BT-Gruppe der gew{\"a}hlten {\"U}bungsanordnung geschuldet sind oder einen generellen Effekt darstellen. Background: Muscle strength and speed are important determinants of soccer performance. It has previously been shown that complex training (CT, combination of strength and plyometric exercises within a single training session) is effective to enhance strength and speed performance in athletes. However, it is unresolved whether CT is more effective than conventional strength training that is delivered in one single block (BT) to increase proxies of athletic performance. Thus, the aim of the present study was to investigate the effects of CT versus BT on measures of muscle strength/power, speed, and agility in elite youth soccer players. Methods: Eighteen male elite youth soccer players conducted six weeks (2 sessions/week, 30 min, each) of progressive CT (n = 10, age: 18,5 +/- 2.2 years) or BT (n=8, age: 18.1 +/- 1.6 years) in addition to their regular soccer training (approx. 6 sessions/week, 60-90 min, each). Before and after training, tests were conducted for the assessment of strength (one -repetition maximum [1RM] squat), power (countermovement jump [CMJ]), speed (30-m linear sprint), and agility (T test). Non-parametric analyses were used to calculate differences within (Wilcoxon test) and between (Mann-Whitney-U test) groups. Results: Both CT and BT proved to be safe (i.e. no training-related, but six match -related injuries reported) and feasible (i.e. attendance rate of 80\% in both groups) training regimens when implemented in addition to regular soccer training. The statistical analysis revealed significant improvements from pre-training to post-training tests for the CT group in 1 RM squat (p =0.043) and CMJ height (p =0,046). For the BT -group, significantly enhanced sprint times were observed over 5 m (p = 0.039) and 10 m (p = 0.026), Furthermore, both groups significantly improved their t test time (CT: p =0.046; BT: p =0.027). However, group comparisons (CT vs. BT) over time (post-training minus pre-training test) did not show any significant differences. Conclusion: Six weeks of CT and BT resulted in significant improvements in proxies of athletic performance. Yet CT did not produce any additional effects compared to BT. Future research is needed to examine whether the observed test-specific changes, i.e. improvements in strength/power for the CT-group and improvements in speed for the BT-group, are due to the applied configuration of strength, plyometric, and sprint exercises or if they rather indicate a general training response.}, language = {de} } @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} } @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} }