COMPARATIVE ANALYSIS OF MUSCLE ACTIVITIES DURING RESISTANCE EXERCISES USING VARIABLE AND ELASTIC LOADS

Abstract

Over the last few decades, many resistance training devices and methods have been deve'loped for the purpose of increasing strength~ One of the most popular devices being used is variable resistance training (VRT) device (Baechle & Groves, 1992). This type of exercise machines has a major advantage that, by altering the shapes of cams, the resistance profiles at different joint positions can match the strength curve (maximum torque-angle curve) of a joint motion. Despite this advantage, the method has not been perfected and there are arguments against its effectiveness (Garhammer, 1989; Ward, 1993). The major disadvantages of this device are the relatively high cost and large space required. The elastic band exercise device such as elastic tubing is getting popular in recent years, especially in rehabilitation settings. To a certain extent, an elastic exercise device has characteristics similar to a variable resistance-training device. The major advantages of this device are its safety, inexpensiveness, and compact design. To evaluate the stresses placed on different upper arm muscles during a biceps curl using selected home exercise devices, it was the purpose of this study to examine the electromyographic (EMG) activities of the pectoralis major, biceps brachii, triceps brachii, and brachioradialis muscles during biceps curls using a VRT device and an elastic tubing.