髌腱末端病运动员膝关节动作反应的变化特征

The characteristics of knee movement response in athletes with patellar tendinopathy

目的:通过对股四头肌收缩过程中的电机械应答现象分析,探讨髌腱末端病运动员膝关节动作反应特征。方法:选择单侧膝关节患有髌腱末端病(PT)的男性运动员11例,分别在屈膝30°、60°和90°条件下,进行膝关节最大伸膝力量(MVC)、动作反应时(TRT)和股四头肌sEMG的测试,比较PT侧和对侧膝关节的TRT和股四头肌的反应前时(PMT)、电机械延迟(EMD)以及sEMG积分值的变化。结果:屈膝30°、60°和90°时,PT侧膝关节TRT均较对侧延长(P<0.05),PT侧膝关节在屈膝30°时的股内侧肌PMT和屈膝90°时的股外侧肌PMT,与对侧比较均延长(P<0.05);PT侧膝关节股内侧肌、股外侧肌和股直肌的EMD与对侧比较均延长,且以股内侧肌EMD变化最为显著。结论:髌腱末端病股四头肌存在肌电激发和收缩时间延迟现象,股四头肌收缩非同步化增加是引起膝关节动作反应迟缓和力量下降的主要因素。

Objective：To investigate the characteristics of knee movement response of athletes with patellar tendinopathy（PT） by analysing the quadriceps electromechanical response during isokinetic contractions.Method：Eleven athletes with unilateral PT participated the study.The indexes,such as maximal voluntary contractions（MVC）,total reaction time（TRT） and sEMG of quadriceps,were tested at the knee angles of 30°,60° and 90°.The TRT and quadriceps pre-motor time （PMT）,electromechanical delay （EMD）,and iEMG of knee with PT were compared with those of knee without PT.Result：The knee TRT with PT was longer than that without PT,at the knee angles of 30°、60° and 90°（P0.05）;PMT of vastus medialis and vastus lateral with PT was longer than that without PT（P0.05）;EMD of vastus medialis,vastus lateral and rectus femoris with PT was longer than that without PT,the changes of EMD of vastus medialis were most significant.Conclusion：Onset of EMG and muscle contraction delayed in quadriceps with PT,increasing of asynchronization of quadriceps contraction was a key factor in the delay of response and low force in extension of knee joint.