Different visual stimuli affect muscle activation at the knee during sidestepping.

Journal of Sports Sciences
Volume 37, 2019 - Issue 10, Pages 1123-1128
DOI: 10.1080/02640414.2018.1545276

Marcus J.C. Lee^a,b, David G. Lloyd^a,c, Brendan S. Lay^a, Paul D. Bourke^a Jacqueline A. Alderson^a,d.

^aSchool of Sport Science, Exercise & Health, The University of Western Australia, Crawley, Western Australia, Australia
^bSingapore Sport Institute, Sport Singapore, Singapore
^cCentre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Queensland, Australia
^dSports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand

Abstract

Increasing knee stability via appropriate muscle activation could reduce anterior cruciate ligament (ACL) injury risk during unplanned sidestepping. High-level athletes may activate their knee muscles differently from low-level athletes when responding to quasi-game realistic versus non game-realistic stimuli. Eleven high-level and 10 low-level soccer players responded to a non game-realistic arrow-planned condition (AP), a quasi game-realistic one-defender scenario (1DS) and two-defender scenario (2DS), and an arrow-unplanned condition (AUNP), that imposed increasing time constraints to sidestep. Activation from eight knee muscles during sidestepping was measured during pre-contact and weight-acceptance. Knee flexor-extensor co-activation ratios were established. Muscle activation levels increased by approximately 27% solely in the 1DS in both sidestepping phases. In the 2DS, the shift from a flexor dominant co-activation strategy in pre-contact toward extensor dominance in weight-acceptance commenced earlier for the high-level players. Quasi game-realistic information allowed for anticipatory increases in knee muscle activation regardless of expertise levels but only when the time demands to respond were low (1DS). High-level players were better at interpreting complex game- realistic information (2DS) to activate their knee extensors earlier in preparation for single-leg landing during weight-acceptance.

Keywords

Sidestep; cutting; EMG; ACL; injury; biomechanics

Prepress PDF of paper