stiffness of the ankle joints in spastic hemiplegia patients

研究痉挛性偏瘫患者踝关节被动运动时发生僵硬的机制。受试者包括15名健康受试者（7名男性和8名女性;平均年龄41.0岁）和30名痉挛性偏瘫患者（16名男性和14名女性;平均年龄55.7岁），处于休息仰卧位，膝关节屈曲0度或80度。每个受试者的两个踝关节被动移动20度，从10度的跖屈，角速度为10度/秒的等速运动机KINCOM-500 H ^<TM>和瘫痪的踝关节也背屈50和100度/秒。测量踝关节被动运动过程中的扭矩、踝关节的角度位置以及胫骨前肌和小腿三头肌的表面肌电图。将每度扭矩的变化定义为刚度。分别采用Ashworth量表和SIAS（stroke impairment assessment set）运动评分评估踝伸肌张力和瘫痪程度，小腿三头肌在10 °/s被动运动时无活动。膝关节伸直位时，瘫痪侧踝关节的僵硬度显著增加，在两个膝关节位置中，瘫痪侧踝关节的僵硬度显著大于非瘫痪侧。根据小腿三头肌在50 °/s和100 °/s被动运动时是否出现牵张反射，将踝关节瘫痪者分为两组，结果表明两组的僵硬度无显著差异。瘫痪踝关节僵硬度与Ashworth量表和SIAS运动评分显著相关。

The mechanism of stiffness that occurs during passive movement of the ankle in patients with spastic hemiplegia was investigated. The subjects consisting of 15 healthy subjects (7 males and 8 females ; mean age 41.0 y/o) and 30 spastic hemiplegic patients (16males and 14 females ; mean age 55.7 y/o) were positioned in a resting supine position with the knees at either 0 or 80 degrees of flexion. Both ankles of each subject were passively moved 20 degrees, from 10 degrees of plantar flexion at an angular velocity of 10 degrees per second by an isokinetic maschine KINCOM-500H^<TM> and the paralyzed ankles were also dorsiflexed at 50 and 100 degrees per second. The torque during passive movement of the ankle was measured together with the angular position of the ankle and surface EMGs of the tibialis anterior and triceps surae muscles. The change in torque per degree was defined as the stiffness. The muscle tone of the ankle extensors and the grade of palsy were evaluated using the Ashworth scale and SIAS (stroke impairment assessment set) motor score respectively.There was no activity in the triceps surae muscles during passive movement at 10 degrees per second. The stiffness in paralyzed ankles significantly increased in the extended knee position, and in both knee positions, the stiffness in paralyzed ankles was significantly greater than in the non-paralyzed side. Those subjects with paralyzed ankles were divided into two groups according to the presence of the stretch reflex in the triceps surae muscles during passive movement at 50 and 100 degrees per second, results indicated that there was no significant difference in the stiffness between the two. The stiffness in paralyzed ankles significantly correlated with the Ashworth scale and SIAS motor score respectively.