Visual Biofeedback Training Method Using a Photoelastic Imaging System (A Clinical Application for Restoring and Stabilizing a Standing Position of Hemiplegic Patients)

Abstract

The efficiency of visual biofeedback (VFB) training method using a photoelastic imaging system on restoring and stabilizing a standing position of stroke patients was investigated. As a stroke group, seven hemiplegics were selected with the mean of 57 year-old. Twelve age-matched healthy subjects were selected as controls. The subjects were asked to stand upright on the photoelastic apparatus and to gaze at a marker 1.5M distant on the wall. Then, VFB training was performed for ten minutes by self recognition of his own pressure patterns which were produced by photoelastic system and were monitored on a TV screen. The patterns were photographed in each different condition such as in a standing position with eyes open or closed before and after 10-minute-training with VFB, and were comparatively analysed. The results showed that (1) the ratio of affected side to unaffected derlnded by the number of first fringes produced increased significantly after VFB up to the control level, (2) the ratio of body weight loading on the affected side to unaffected was significantly increased after VFB, and (3) the position of center of contact pressure on the longitudinal axis of an affected sole was found to be significantly more posteriorly sifted than in the control and was remained unchanged after VFB. In conclusion, the VFB method using a photoelastic imaging system may be useful to enhance visual-contact motor balancing functions in patients with hemiplegics and also to study a restoring process of neurological impairment leading to a postural problem. © 1995, The Japan Society of Mechanical Engineers. All rights reserved.