ESTIMATED MUSCLE FORCES ANALYZES DURING CONCENTRIC-ECCENTRIC SHOULDER EXTERNAL AND INTERNAL ROTATION

Abstract

The purpose of this study was to analyze the muscle force production during eccentric/concentric shoulder internal and external rotation with 90° of abduction. Six male subjects performed five repetitions of maximal concentric and eccentric contractions rotation without interval, with a mean angular speed of 60°/sec. A biomechanical model was implemented to estimate muscle force and moment. Infraspinatus, supraspinatus and teres minor presented the larger peak moment values during external rotation (concentric and eccentric). Subscapularis, pectoralis major and teres minor presented the larger peak moment values during internal rotation (concentric and eccentric). The eccentric contraction allowed larger peak muscle forces and moments and the correspondent angles were altered, if compared to concentric conditions. The results presented are useful as guidelines for shoulder rehabilitation programs.