인간의 수행 요소인 국소 근육의 피로는 만성적인 손상을 초래한다. 이 연구는 근전도의 진폭(amplitude)과 근력(muscle force)에서 피로의 영향을 WL과 NWL로 비교하여 조사하였다. 손목 굽힘근의 근력은 시간이 흐름에 따라 WL과 NWL 모두에서 감소되었다. 그러나, WL과 NWL는 시간 경과에 따른 근전도 진폭에서는 차이를 보였다. WL의 근전도 진폭에서는 운동 후 48분에 가장 높은 변화를 보였다. 이를 통하여 근전도의 진폭파 근력이

Skeletal muscle fatigue is often associated with diminished athletic performance and inability to maintain an expected force output as a function of time. The purpose of this study was to compare the effect of duration of exercise on skeletal muscle fatigue between Weight Lifters(WL) and Non-Weight Lifters(NWL). There were twelve normal healthy adult volunteers, ranging in age from 18 to 35 years. The group consisted of six NWL and six WL. Randomized cross-over design was set up and work-rest cycle was 8 minutes work and 1 minute rest based on 15% MVC. Muscle fatigue was measured by the amount of force produced by the wrist flexor muscle and EMG amplitude over time. Repeated measures ANOVAs() were used to determine two types of subjects(WL, NWL) during four different duration of exercises(16, 32, 48, 64 minutes). The force decreased over time in NWL and WL, but there was no significant difference(F=2.83, p>0.05). However, the EMG amplitude increased in WL(0.8200) and NWL(0.6348). The WL exhibited an increase in EMG at the end of the period, especially at 48 minutes of exercises than did the NWL(F=9.58, p<.05). This suggests the WL were able to adjust to prolonged effort with adaptations in neural effect over time, resulting in higher EMG amplitude. That is, WL may be able to learn to recruit more motor units with training. It is important to the degree of neuromuscular fatigue and the time needed for recovery may differ considerably between WL and NWL, there is a need to plan proper strength training or rehabilitation protocols to match with the requirements in different characteristics of groups.

• Paul S. Sung(성어거스턴대학 물리치료 박사 과정) | 성수원