COMPARISON OF ELECTROMYOGRAPHIC ACTIVITY BETWEEN ACTIVE AND PASSIVE MUSCLE TRAINING MOVEMENT

Abstract

Passive Repeatedly Plyometric (PRP) training machine was developed on the scientific of neuromuscular system such as recruited more motor units, stretch reflex, storage elastic energy and so on. It used a motor to drive a cam, and the cam can control trainee's movement passively and repeatedly. So it has some advantages to control the training load, speed of muscle contraction, and length of muscle contraction during training. Some researches have demonstrated that PRP was an efficient strength training approach, and it could significantly improve strength and power than traditional weight training (Liu et ai, 2001). Moreover, Wang et al (2001) and Wen et al (2001) found out that EMG activity in PRP were significantly higher than in traditional weight training. In fact, trainee must push the bar upward with maximum strength during PRP training. So muscles of trainee accomplished isometric contraction, and then concentric and eccentric contraction passively with maximum muscle strength. In other word, the trainee's muscles should follow isokinetic contraction way during PRP training. EMG activity was unclear in this case so far. Therefore, the purpose of this study was to investigate the EMG activity among PRP with and without maximum isometric contraction during training, as well as active muscle contraction by free weight training.