EFFECT OF FATIGUE ON ELECTOR SPINAE MUSCLES ON TRUNK POSTURAL KINEMATICS AND ELECTROMYOGRAPHYIC ACTIVITIS DURING REPETITIVE BACK SQUAT

Abstract

The aim of the present study was to demonstrate the change of the trunk posture and electromyographic (EMG) activities of elector spinae muscle and lower extremity muscles during repetitive squat motion in two different conditions with or without the back muscle fatigue task. The results demonstrated that forward trunk inclination was significantly increased during the no-fatigue condition. In addition, the forward trunk inclination appeared to be greater in the pre-fatigue condition than the non-fatigue condition. In addition, the EMG activities in the erector spinae muscles were significantly increased in the non-fatigue condition, but not in the EMG activities in the pre-fatigue condition. Appropriate muscle strength must be necessary for squat exercise to maximize the training effects and to avoid lower back injuries.