膝关节角度对屈伸肌共同收缩及伸膝力矩的影响  

The effect of knee joint angle on coactivation of agonist and antagonist muscles and torque generation in knee extension

作　　者：李嘉祁 徐艳文[2] 张卓[3] 张奇[4] Kari Chow 

机构地区：[1]龙岗中心医院康复医学科,深圳518123 [2]广东省工伤康复中心 [3]香港理工大学康复科学系 [4]中国康复研究中心物理治疗科

出　　处：《中华物理医学与康复杂志》2007年第6期405-408,共4页Chinese Journal of Physical Medicine and Rehabilitation

摘　　要：目的应用表面电极肌电图(EMG)测量膝关节在不同角度做开放链最大等长伸膝时屈膝肌的共同兴奋能力,比较不同角度膝屈伸肌的共同兴奋水平。方法12名健康在校大学生参与测试。每名受试者在Cybex测试仪上髋关节屈曲90°,单侧膝关节分别于屈膝10,60和90°时各做1组开放链的最大等长伸膝动作。使用表面电极EMG测量每次膝关节伸展时股四头肌与腘绳肌的电信号。在每次伸膝的同时用Cy- bex测量股四头肌的最大伸膝力矩。结果所有角度下股四头肌的最大等长收缩均伴腘绳肌的共同兴奋。平均最大伸膝力矩出现在屈膝60°(P<0.05)。结论膝关节在屈膝60°时可产生最大等长伸膝力矩,开放链的伸膝肌等长收缩伴有屈膝肌的共同兴奋。Objective To investigate the coactivation ability of knee flexors during open kinetic chain （OKC） maximal isometric knee extensor contraction at different joint angles with EMG, and to compare the activation levels of knee extensors and flexors at different joint angles. Methods Ten health pros-graduated students were recruited to participate the project. Each subject was asked to perform maximum voluntary isomeric knee extension at three different knee flexion angles with hip fixed at 80° flexion individually on Cybex Norm Isokinetic Testing and Rehabilitation System. A surface electromyography system with preamplfied bipolar circular surface electrodes attached on quadriceps and hamstrings muscle was used to collect and measure electric signal and muscle activities of quadriceps and hamstring. Results Coactivation of the hamstring was found by the EMG measurement during the knee extension at any one of the tested joint angles and each trail. One-way ANOVA with post-hoc testing indicated that the mean torque of quadriceps with knee at 60 and 90 was significantly greater at 30 （ P 〈 0.05）. The highest mean activation level of quadriceps was appeared at 60 of knee extension （ P 〈 0.05）. Conclusion The results showed that the greatest MVIC-torque of quadriceps occurred at a knee angle of 60 degree extension. Co-activation of quadriceps and hamstring at certain angles can help to maintain the stability of knee joint. However, no significant relationship of MVIC-EMG and MVIC-torque of quadriceps was found in our study. Further investigation of the relationship between torque and EMG under different hip joint angles is suggested. For co-activation of quadriceps and hamstrings, subjects with ACL deficient should also be involved for comparison.

关 键 词：膝关节 开放链 共同兴奋 表面肌电图 

分 类 号：R49[医药卫生—康复医学]