Reaction and movement times in patients with hemiparesis for unilateral and bilateral elbow flexion

Abstract

Background and Purpose. This work was designed to study the effects of bilateral elbow flexion on the reaction and movement times of the impaired upper extremity of patients with hemiparesis. Subjects. The subjects consisted of an experimental group of patients with hemiparesis (n=25) and a control group of age-matched healthy volunteers (n=26). Methods. Each subject performed three sets of 16 elbow flexion trials. Two of these sets required unilateral movements, one for each upper extremity. The third set of movements required simultaneous elbow flexions of both upper extremities. In each trial, subjects were instructed to flex their elbows in response to an auditory signal from a supported initial position of 150 degrees through a goal orientation of 120 degrees. 'Reaction time' was defined as the time between the auditory signal and movement initiation. 'Movement time' was defined as the time between movement initiation and the completion of 30 degrees of elbow flexion. Results. When subjects were asked to bilaterally flex their elbows, the reaction and movement times increased in both extremities. Conclusion and Discussion. It was speculated that in patients with hemiparesis, movement time of the nonparetic extremity in the bilateral task is limited by the rate of performance of the paretic extremity. The decrease in speed of these performance-determining variables in the bilateral task warrants consideration during physical therapy intervention for patients with hemiparesis.