TY  - JOUR
A1  - Lesinski, Melanie
A1  - Prieske, Olaf
A1  - Borde, Ron
A1  - Beurskens, Rainer
A1  - Granacher, Urs
T1  - Effects of Different Footwear Properties and Surface Instability on Neuromuscular Activity and Kinematics During Jumping
JF  - Journal of strength and conditioning research : the research journal of the NSCA
N2  - 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.
KW  - shoe
KW  - drop jump
KW  - EMG
KW  - knee
KW  - biomechanics
Y1  - 2018
U6  - https://doi.org/10.1519/JSC.0000000000002556
SN  - 1064-8011
SN  - 1533-4287
VL  - 32
IS  - 11
SP  - 3246
EP  - 3257
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  -