ILIOPSOAS MUSCLE ACTIVITIES IN HEMIPLEGIC GAIT

从偏瘫步态的时间因素观察，认为步态速度的提高可能依赖于步态周期中站立期的缩短，尤其是双加速站立期的缩短。两个结构被认为在这一时期有重要作用;它们是代表膝关节伸展机制的下肢反重力肌肉的作用，以及引发下肢摆动的髂腰肌的作用。偏瘫步态的肌电图研究表明：1）髂腰肌在整个步行周期中与对照组一样呈阶段性活动，可能与偏瘫步态中双加速期延长无关; 2）臀中肌、股外侧肌、内侧腘绳肌在正常步行周期中呈动态活动，与下肢协调运动有关。在偏瘫步态中，这一时期的异常不适当活动被认为是影响双加速期的一个因素;（3）小腿三头肌也被认为是双加速期延长的一个因素，由于缺乏动力性放电而干扰了最佳的膝关节屈曲和髋关节屈曲;（4）改善偏瘫患者的双加速期或步行能力，下肢的支撑系统必须集中，而不是在本研究开始时假设的不适当的髂腰肌活动。

From the observation of time factor in hemiplegic gait, it was thought that the improvement of the gait speed might be dependent on the shortening of the stance phase of gait cycle, especially on the double accelerating stance period. Two structures were thought to have important roles for this period ; they were the role of anti-gravity muscles of the lower limb that represents the knee extension mechanism, and the role of the iliopsoas muscle that initiates swing of the lower limb. From EMG study of hemiplegic gait, followings were revealed1) Iliopsoas muscle showed phasic activity like the control group through the walking cycle, so that this muscle may not concern with prolongation of double accelerating period seen in hemiplegic gait.2) Gluteus medius, vastus lateralis, medial hamstrings showed dynamic muscle activities contributing to coordinative lower limb motion in normal walking cycle. In hemiplegic gait, their abnormal inappropriate activities in this period were thought as a factor that prolongs double accelerating period.3) Triceps surae was also thought as a factor of prolonged double accelerating period, disturbing optimal knee and hip flexion due to lack of dynamic discharge.4) Improving the double accelerating period or the walking capability in hemiplegic patients, supporting system of the lower limb must be focused rather than inappropriate iliopsoas activity which was hypothesized at the beginning of this research.