stiffness of the ankle joints in spastic hemiplegia patients

对痉挛偏瘫患者踝关节被动活动时僵硬的机制进行了研究。受试者包括15例健康受试者(男7例，女8例，平均年龄41.0岁/o)和30例痉挛偏瘫患者(男16例，女14例，平均年龄55.7 y/o)。每个受试者的双踝都以每秒10度的角速度从足底前屈10度被动移动20度，瘫痪的脚踝也以每秒50度和100度的角速度背屈。测量踝关节被动运动时的扭矩、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信号。每度扭矩的变化定义为刚度。分别用Ashworth评分和SIAS(卒中损伤评估集)运动评分评定踝伸肌肌张力和瘫痪程度。被动运动10度/秒时，小腿三头肌无活动。伸膝姿势时瘫痪踝关节的僵硬程度显著增加，且在两个膝关节姿势下，瘫痪踝关节的僵硬程度均显著大于非瘫痪侧。根据小腿三头肌在50度/秒和100度/秒被动运动时伸展反射的存在，将瘫痪的踝关节分为两组，结果表明，两组的僵硬程度无显著差异。瘫痪踝关节的僵硬程度分别与Ashworth评分和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.