Effect of ankle disk training combined with tactile stimulation to the leg and foot on functional instability of the ankle.

Twenty-two university students with unilateral functional instability of the ankle participated in this study. They were randomly assigned to one of two experimental groups. Subjects in both groups were trained to stand on the affected limb on an ankle disk. In group 1, two pieces of 1-cm wide nonelastic adhesive tape were applied to the skin around the lateral malleolus from the distal third of the lower leg to the sole of the foot before the training sessions. Subjects in group 2 participated in the training sessions without the application of the adhesive tape. Training was performed for 10 minutes a day, five times per week, for a period of 10 weeks. Subjects were tested for postural sway while standing on the affected limb before, during, and after the training period. In group 1, postural sway values decreased significantly after 4 weeks compared with the pretraining performance, and they were within the normal range after not more than 6 weeks of training. In group 2, the values did not improve significantly compared with the pretraining performance until after 6 weeks of training, and they were not within the normal range until after 8 weeks of training. The findings suggest that the 2-week earlier correction of postural sway in group 1 was due to an increased afferent input from skin receptors that were stimulated by the traction of the adhesive tape.