Abstract

The purpose of this study was to assess dynamic muscle activity during isotonic, variable-resistance, and isokinetic exercises. Ten subjects were tested on free weight, Nautilus, and Cybex equipment. Electromyographic (EMG) activity of the vastus medialis, semimembranosus, biceps brachii, and triceps was measured. Results show that isokinetic exercise maintained a steady muscle activity for all muscle groups. Isotonic exercise produced an unexpected steady pattern in the semimembranosus, and variable-resistance exercise produced a changing pattern in the vastus medialis. This study demonstrates that muscle activity can vary in different muscles using variable-resistance and isotonic exercises, but isokinetic exercise has a consistent effect in all muscles tested. Verf.-Referat