不同训练经历者六周负重蹲起训练后股四头肌和腘绳肌最大用力时表面肌电振幅变化的对比研究

Comparison of the IEMG Amplitude of Quadriceps and Hamstring before and after 6-week Dynamic Resistance Training in Trained and Untrained Individuals

目的:通过对比有无训练经历者抗阻训练前后表面肌电振幅的变化,探讨力量训练后神经适应的方式。方法:有训练经历组(TG)、无训练经历组(UG)各8人,均为青年男性。进行6周杠铃负重蹲起训练,比较受试者训练前后的负重蹲起1RM重量和完成1RM时股四头肌和腘绳肌表面肌电振幅平均积分。结果:训练后两组受试者1RM重量(kg)均显著增加(UG:121.7±9.0vs179.4±18.8;TG:165.6±16.4vs220.6±17.2)。与训练前比较,训练后完成负重蹲起1RM时股四头肌表面肌电振幅均值(mV)均有所降低,股外侧肌:0.78±0.33vs0.57±0.34(UG),0.92±0.38vs0.65±0.13(P<0.05,TG);股直肌:0.73±0.21vs0.65±0.21(UG),0.79±0.18vs0.65±0.22(P<0.05,TG);股内侧肌:0.72±0.33vs0.72±0.29(UG),0.87±0.23vs0.71±0.22(TG)。结论:训练后最大力量增加的神经适应的主要方式可能并非仅是运动单位募集数量的增加,而是各运动单位之间的活动更为精确协同;最大力量可能是在神经冲动适宜条件下产生的。

Objective To compare the IEMG amplitude of quadriceps and hamstring in trained and untrained individuals before and after dynamic resistance training. Methods Eight untrained （UG） and 8 trained （TG） young male volunteers took part in 8RM weight barbell squats training, twice a week for 6 weeks. Surface IEMG amplitude of quadriceps and hamstring during 1RM knee extension was recorded before and after training. Results After 6 weeks of training, the 1RM weight （kg） increased significantly： 121.7±9.0 vs 179.4±18.8 in UG and 165.6±16.4 vs 220.6±17.2 in TG, respectively. The average surface IEMG amplitude（mV） of quadriceps during IRM barbell squatting declined as followed： 0.78±0.33 vs 0.57±0.34 in UG and 0.92±0.38 vs 0.65±0.13 in TG for vastus lateralis （P〈0.05）; 0.73±0.21 vs 0.65±0.21 in UG and 0.79±0.18 vs 0.65±0.22 in TG for rectus femoris （P〈0.05）;and 0.72±0.33 vs 0.72±0.29 in UG, and 0.87±0.23 vs 0.71±0.22 in TG for vastus medialis, respectively. Conclusion Nerve adaption increases muscle strength after resistance training, which probably attributes to the improvement of cooperation in motion units.