The aim of the study was to find the difference in the lengths of the muscular spindle and tendon when performing a semi-squat and a deep squat. The study involved 5 men who are professionally engaged in powerlifting. Graphs of the dependence of the length of the "muscle-tendon" system are constructed from the time of performing exercises for the rectus femoris muscle for all participants. It was revealed that four participants had an increase in the length of the rectus femoris muscle on both legs with a deep squat, compared with a semi–squat, and one had a decrease. An asymmetry in the indicators between the left and right legs was revealed in a participant who previously had a patellar injury.
biomechanics, sports, video analysis, OpenSim, Qualisys, semi-squat, deep squat
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