【作者】 陆俊杰；

【导师】 王国祥；

【作者基本信息】 苏州大学 ， 运动人体科学， 2010， 硕士

【摘要】 研究目的:股四头肌是伸膝装置的主要结构,股四头肌的肌力平衡对髌股关节接触应力和分布状态以及髌骨运动轨迹等均有较大影响。本研究采用等速测力系统与肌电图技术,对膝关节在不同运动模式,股四头肌疲劳前后的表面肌电图和动作反应时变化进行分析,目的为进一步揭示股四头肌在膝关节运动中的作用规律提供理论依据。研究方法:受试者为12名男性青年,利用CON-TREX等速肌力测试系统,对受试者在不同运动模式进行疲劳测试,同时对股直肌、股内侧肌、股外侧肌进行表面肌电信号的采集与记录,分析股四头肌在不同运动模式疲劳前后动作反应时及其表面肌电图的iEMG和MF变化。研究结果:(1)股四头肌疲劳后的iEMG和MF均明显低于疲劳前水平,统计学分析呈显著性差异(p<0.05或p<0.01);(2)不同运动模式疲劳后股四头肌各肌肉RT值变大(p<0.01),向心疲劳模式疲劳后即刻10s比疲劳前增加了81.08ms,离心疲劳模式疲劳后即刻10s比疲劳前增加了81.71ms,等长疲劳模式疲劳后即刻10s比疲劳前增加了67.82ms;(3)不同运动模式疲劳后股四头肌各肌肉PMT值变大(p<0.01),股内侧肌离心疲劳模式疲劳后PMT增幅最大,即刻10s比疲劳前增加了110.03ms,股直肌等长疲劳模式疲劳后PMT增幅最小,即刻10s比疲劳前增加了79.91ms;(4)不同运动模式疲劳后股四头肌各肌肉EMD值变小(p<0.01),等长疲劳模式疲劳后股内侧肌的EMD值降幅最大,在3min时段下降了39.54ms,等长疲劳模式疲劳后股直肌的EMD值降幅最小,在10min时段下降了13.81ms。研究结论:(1)股四头肌疲劳导致膝关节伸膝力量下降状态下、以股内侧肌表面肌电图的iEMG和MF变化最为明显;(2)伸膝运动时股四头肌群中股内侧肌产生动作电位时间,明显快于股外侧肌和股直肌;(3)股四头肌RT的延长,主要是受PMT的影响。更多还原

【Abstract】 Objective: Quadriceps femoris are the main knee extensors. Muscle balance of them has a great impact on the contact stress and the distribution state of the patellofemoral joint, and on patella trajectory as well. In this study, effects of different fatigue modes on reaction time and sEMG, are investigated, In order to provide a theoretical basis for further revealing the quadriceps activity patterns of the knee joint.Methods: The knees of 12 male subjects were tested in this study. The CON-TREX isokinetic dynamometer and the biovision system were synchronously used to collect peak torque, the angle of the joint and sEMG of rectus femoris(RF), vastus medialis (VM) and vastus lateralis (VL) during the different fatigue modes. The action time, iEMG and median frequency(MF) of sEMG were the dependent variables before and after the exercise .Results: (1) During exercise, iEMG and MF of the quadriceps decreased significantly(P <0.05orP <0.01).(2) The RT of quadriceps femoris are higher significantly after than before exercise, 81.08ms higher immediately after than before concentric exercise (p < 0.01), 81.71ms higher immediately after than before eccentric exercise, 67.82ms higher immediately after than before isometric exercise. (3) The PMT of quadriceps muscle increases significantly after exercise (p < 0.01) . The Vastus medialis’is 110.03ms more higher after than before eccentric exercise, The Rectus femoris’is 79.91ms higher after than before isometric exercise, but the growth is the smallest(.4) The EMD of the quadriceps decreased after exercise (p < 0.01). The Vastus medialis’is 39.54ms lower within 3min after than before isometric exercise, and the decline is the highest. The Rectus femoris’is 13.81ms lower within 10min after than before isometric exercise, and the decline is the lowest.Conclusion:(1) iEMG and MF of Vastus medialis muscle of sEMG change most obviously among the quadriceps after than before exercise(.2) During the extension of the knee joint, the generation of action potential in Vastus medialis muscle is earliest among the quadriceps.(3) The RT of the quadriceps is mainly dependent on PMT.更多还原