Benefits of short-term training with vibrotactile biofeedback of trunk sway on balance control in multiple sclerosis

Background and aims: Patients with multiple sclerosis (MS) suffer from diminished balance control. We examined whether 4 sessions of training with vibrotactile biofeedback (VTfb) of trunk sway could improve their balance control and provide a carry-over effect. Methods: Baseline trunk sway was first measured for 15 MS patients. Then they received head mounted VTfb of trunk sway which was directionally active when trunk sway exceeded limits set using the baseline assessments. Stance and gait tasks were trained 2 times weekly for 2 weeks with VTfb. Assessments with VTfb were performed at the end of each week. Two weeks later balance was assessed without VTfb to determine if a carry-over effect was present. Results: Assessments with VTfb showed a significant decrease in trunk sway after 1 and 2 weeks of VTfb training (p<0.02). Carry-over improvements were also present (p<0.02). The greatest effects were found for tests of standing eyes closed stance on foam which resulted in a 59% decreased pitch sway angle (p=0.002) with VTfb and a 51% reduction (p=0.03) carry-over effect. Conclusions: This study indicates that balance control in MS patients improves rapidly after one week of training with VTfb and more slowly subsequently. The carry-over effect lasted at least 2 weeks. Future studies should determine, with more weeks of VTfb training, the time course of the slower balance and carry-over improvements following the first rapid improvement in balance control. We conclude that training with VTfb of trunk sway significantly improves balance control in MS patients, and could possibly reduce falls.