Meaurement of the Muscle Fatigue Patterns using Electromyography Technique

Ahn, Jae Yong; Han, Jung Soo; Min, Ki Sik

Abstract

Injuries and pains of musculoskeletal joint in human body is common onset in industrialized world. However, muscle fatigue plays a very significant role in contributing causes of many pains associated with musculoskeletal joints. Based on this hypothesis, degree of muscle fatigue was investigated using electromyography measurement technique during isometric and concentric/eccentric muscle contractions. Different response of the muscle fatigue between two different muscle contractions (isometric and concentric/eccentric contractions) was examined by comparison of parameters which were median frequency, median power and RMS value. Healthy 16 young persons without previous musculoskeletal diesease history were tested with Noraxon Myosystem 2000 EMG measurement system. In this study, two different exercises were performed. First exercise was concentric/eccentric exercise. Second exercise was isometric muscle contraction. In the case of the isometric exercise, median frequency was decreased, but median power and RMS were increased. However, during the concentric/eccentric exercse, median frequency was increased, but median power and RMS were decreased. Both of those revealed that the pattern of the median frequency was W type, but median power and RMS were M type as time passed. In this study, the patterns of the muscle fatigue during concentric/eccentric exercise as well as isometric exercise were identified. It will be helpful to prevent musculoskeletal injury from over-working andexercising.