Development of a rehabilitation apparatus to actuate upper extremity passive motion

An apparatus that can induce upper extremity passive motion in stroke patients was developed with the goal of providing rehabilitation for these individuals. The rehabilitation device consists of a robotic arm controlled by a computer interface and programmed to effect passive extension and flexion of the patient's elbow and fingers. The load imposed on the upper limb and fingers was analysed. A high-speed video camera captured the trajectory of the subject's arms and a kinetic model based on the arm structure was employed to analyse the trajectory. Results showed that the range of motion (ROM) of the subjects' elbows was between 77-158 degrees (about 80 degrees ROM) and the average range of movement from extension to flexion of the fingers was approximately 3 cm. The average loading moment on the shoulder and elbow was below 12 N-m. By varying the angular position and angular velocity of the robotic arm, the programme reproduced the motions of different arm functions. Thus, the present study shows that the apparatus provides safe and effective simultaneous rehabilitation of both the elbow and fingers, and that the use of this device may benefit patients undergoing rehabilitation in a clinical setting.