Differences in Concentrically and Eccentrically Determined Local Muscle Endurance of the Shoulder Musculature with Different Training Status

Abstract

Past investigations have shown that greater force occurs under eccentric stress of a muscle group than in isometric and concentric modes of exercise (1,2,5). Additional passive elastic forces are seen as the cause (2,5). Most of the available studies are concerned with large muscle groups such as knee extensors and flexors (3,9). Isokinetic strength measurements of smaller muscle groups like the shoulder musculature show only small differences in eccentric strength development compared to isometric exercises in untrained male and female individuals (6,7). It is also known that higher maximum strength capacity is evolved during eccentric stress of the shoulder musculature in sports with mainly shoulder stress (7). The decrease in maximum torque with increasing movement velocity under concentric exercise conditions can be demonstrated (2,4,6).