자연과학편 : 속도 및 부하 조건에 따른 슬관절 신전근의 단축성 수축과 신장성 수축시 근육활동 형태에 대한 근전도 분석 = Muscle Activity Patterns During Concentric and Eccentric Contractions of The Knee Extensor on Different Speed and Load Conditions

다국어 초록 (Multilingual Abstract)

The purpose of this study was to investigate the muscle activity patterns during concentric and eccentric contraction of the knee extensor muscle(m. rectus femoris) and to determine how the muscle activity patterns change as the angular speeds(60, 120, 180˚/sec) and loads(30 & 60% max load) are varied. Ten healthy university students(male) performed the concentric and eccentric movements with a leg extention machine. The EMG activity was recorded from the m. rectus femoris with a Lafayette Instrument EMG Model 76409 and pairs of surface electrodes at a sampling rate of 1000 ㎐. The EMG data was scaled based on the standardized EMG values(MVC) on m. rectus femoris and a ANOVA Repeated Measures & Sheffee’ test(p<.05) was employed for statistic analysis. The results revealed that the IEMG activity of concentric muscle contraction on 30% max load increased with increasing knee angular velocity from 60˚/sec to 120˚/sec & 180˚/sec(p<.05). but eccentric contraction did not. The concentric contraction had higher IEMG activity than eccentric contraction on every conditions(p<.05). The IEMG activity during eccentric contractions at 120˚/sec and 180˚/sec was greater in the 60% max load than in the 30% max load (p<.05).In conclusion, the results indicated that speed is not a significant factor in influencing the IEMG activity in eccentric muscle contractions. Also, the data supports that the eccentric muscle contraction at 60-180˚/sec have less IEMG activity than concentric muscle contractions and the loads had greater effects on the eccentric contraction than on the concentric contraction.