Effect of Weight-Shifting Practice Using Auditory Feedback on Postural Control in Patients With Body Lateropulsion: A Single-Case Experimental Design

Body lateropulsion (BL) is a postural control disorder commonly associated with unilateral brainstem or cerebellar lesions. Patients with BL exhibit a tendency to lean toward one side and experience difficulty maintaining stable standing and walking. Although exercises focused on visual or somatosensory cues have been proposed, no standardized interventions have been established. Auditory feedback has emerged as a promising new approach, as it can complement visual and somatosensory inputs to improve balance. This single-case study investigated whether incorporating auditory feedback into standing weight-shifting exercises could enhance postural control in patients with BL. A man in his 60s with BL following a left cerebellar hemorrhage participated in an ABA (A: control phase, B: intervention phase) single-case study design. Each phase (A1, B, A2) lasted seven days, with weight-shifting exercises performed daily. During the A1 and A2 phases, the patient performed weight-shifting exercises without auditory feedback. In the B phase, auditory feedback was incorporated using a shoe-based load meter. Primary outcomes included center of pressure (COP) measures, COP velocity, perimeter area, and mediolateral COP position, recorded under eyes-open and eyes-closed conditions. Secondary outcomes included the Scale for the Assessment and Rating of Ataxia (SARA), the Berg Balance Scale (BBS), and subjective visual vertical (SVV). Compared to the A1 phase, the B phase demonstrated significant improvements in COP velocity, perimeter area, and mediolateral COP position. These improvements were maintained after auditory feedback was removed in the A2 phase. Although ataxia and balance ability improved over time, the changes did not exceed the minimal detectable change (MDC) or the minimal clinically important difference (MCID). The SVV deviation showed slight improvement but remained outside the normal range. Incorporating auditory feedback into weight-shifting exercises improved postural stability in a patient with BL. These findings suggest that auditory cues may facilitate proprioceptive reweighting and motor learning in postural control, independently of improvements in vestibular function or visual vertical perception. Further studies with larger sample sizes are needed to validate these results and elucidate the underlying mechanisms.