Training procedures and biofeedback methods to achieve controlled partial weight bearing: an assessment.

Limiting weight bearing to a prescribed level is clinically desirable when patients use crutches or canes or wear prostheses. Several training methods currently being used in clinical settings were tested. These included the use of bathroom scales, and several more sophisticated feedback systems, to train normal subjects to limit weight bearing on a protected limb to a target load. It was found that such training was of limited value since subjects, during training and after, often exceeded target loads by 50% or more. Any retained learning was found to diminish rapidly on the first and second days after training. Even when using continuous auditory feedback, overshoot of the target load seemed inevitable due to the time lag between auditory perception and motor response, and the rapid rate of loading of the extremity.