The power of instruction on retropulsion: A pilot randomized controlled trial of therapeutic exercise focused on ankle joint movement in Parkinson’s disease

INTRODUCTION: Although retropulsion is a serious complication of Parkinson’s disease (PD), it is unknown whether ankle joint movement patterns can be targeted to treat retropulsion. The primary aim of this study was to investigate the effectiveness of therapeutic exercise focused on instructions regarding ankle joint movement on retropulsion in PD. METHODS: Twenty patients with moderate PD were randomly allocated to the experimental intervention (INSTR) or control groups. The INSTR group received a 2-week therapeutic exercise program (40 min/day, five times/week) that involved repeated backward pulls on the shoulders with instructions to land on the toes as a response, and the control group received the same intervention without the instructions. The primary outcome was the difference in changes from baseline in the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS part III) score between the study groups at weeks 1 and 2. RESULTS: The improvement in the MDS-UPDRS part III scores was significantly greater for the INSTR group in the week 1 (p = 0.033, (p)η(2) = 0.241) and week 2 (p = 0.004, (p)η(2) = 0.401) assessments. However, the provision of instructions to land on the toes as a backward response induced improvement in the only scores related to the backward response, and no significant between-group differences were observed in the other outcomes. CONCLUSION: The 2-week therapeutic exercise program with instructions to treat retropulsion improved the backward response. TRIAL REGISTRATION: UMIN-CTR, UMIN000042722.