TY  - JOUR
A1  - Prieske, Olaf
A1  - Demps, Marie
A1  - Lesinski, Melanie
A1  - Granacher, Urs
T1  - Combined Effects of Fatigue and Surface Instability on Jump Biomechanics in Elite Athletes
T2  - International journal of sports medicine
N2  - 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.
KW  - stretch-shortening cycle
KW  - knee joint angle
KW  - exhaustion
KW  - injury risk
KW  - gender
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/46399
SN  - 0172-4622
SN  - 1439-3964
VL  - 38
SP  - 781
EP  - 790
PB  - Thieme
CY  - Stuttgart
ER  -