Targeted Ankle Proprioceptive Training Improves Balance, Gait, and Functional Mobility in Chronic Stroke Survivors: A Multicenter Randomized Controlled Trial with Longitudinal Follow-Up

Abstract Background: Ankle proprioceptive impairment is a key predictor of persistent balance and gait deficits following stroke, with strong cross-sectional associations particularly to inversion proprioception. However, causality, longitudinal progression, and efficacy in moderate-to-severe or non-ambulatory chronic cases remain unestablished. Objective: This multicenter randomized controlled trial aimed to evaluate the causal effects of targeted ankle proprioceptive training on balance, gait, and functional mobility in chronic stroke survivors across severity levels, including long-term retention and proprioceptive trajectories across stroke stages. Methods: 140 chronic stroke participants (mean age 58.4 ± 11.2 years; 18–72 months post-stroke) were randomized to 12 weeks of targeted proprioceptive training (n=70; robotic-assisted discrimination plus weight-bearing tasks emphasizing inversion) or standard rehabilitation (n=70). Primary outcome: weight-bearing ankle proprioception (Active Movement Extent Discrimination Apparatus, AMEDA). Secondary outcomes: Berg Balance Scale (BBS), Timed Up and Go (TUG), 10-meter walk test, Fugl-Meyer Lower Extremity, and Functional Ambulation Category. Assessments occurred at baseline, post-intervention, and 6-month follow-up. A longitudinal subsample (n=42) tracked proprioceptive changes from acute to chronic phases. Results: The intervention yielded significant, clinically meaningful improvements in inversion proprioception (affected side Δ=0.21 AUC), balance (BBS +12.4 points), gait speed (+0.32 m/s), and mobility (all p