A biofeedback study of postural sway.

An experiment was performed to control postural sway under auditory and visual feedback signals using a new apparatus. The subjects of 52 healthy high school girls were divided into 13 small groups. Each small group had four subjects who were assigned to one of the following four groups; 1) visual feedback group, 2) auditory feedback group, 3) auditory and visual feedback group, and 4) control group. Comparisons were made as to the duration of the green lamp being on, which indicated sway stayed around the initial central gravity. The results showed that auditory and visual feedback groups had a significant increase in the duration as compared to other three groups. With regard to the changes in the areas of postural sway, the largest increase was seen in the auditory and visual group. While the three feedback groups showed downward curves, the control group showed an upward one. Thus it is suggested that postural sway can be voluntarily controlled by a combination of an auditory feedback procedure and a visual feedback procedure, but not by either of them independently.