Relationship Between Hypertonicity and Tendon Reflex

The purpose of this study was to investigate the relationship between clinical classification and quantitative measurements using electromyography (EMG) during tendon tap. Fifteen hemiplegic patients and six patients with parkinsonism were studied. Eleven healthy subjects were measured as controls.The clinical classification as a qualitative evaluation was performed based on the response to stretch of biceps brachii using manual operation. A manner of hypertonicity was classified as spasticity, rigido-spasticity, lead pipe rigidity and cog-wheel rigidity. Otherwise, a grade of hypertonicity was classified by using Ashworth Scale. The measurement of tendon reflex was performed by manual tap utilizing a hand-held electronic reflex hammer.EMG signals from biceps brachii during tendon tap were analyzed using personal computer and signal processing software. Integrated EMG (I-EMG) and duration of T-wave induced by tendon tap were compared with qualitative and quantitative classification. Ⅰ-EMG of T-wave in hypertonicity showed significant increase in contrast with normal controls(p< 0.05). Significant relationship between T-wave and qualitative and quantitative classification, however, was not revealed. It can be concluded that there were some kind of differences in neural circuits between clinical evaluation of hypertonicity and examination of T-wave