Split-Belt Treadmill for Falls, Gait Asymmetry, and Freezing in Parkinson's Disease

Background: Individuals with Parkinson's disease (PD) can adapt to new gait patterns on a split-belt treadmill (SBTM), a tool previously used to rehabilitate gait asymmetry because of stroke. Objectives: The goal was to determine whether SBTM rehabilitation is superior to conventional "tied" treadmill (TM) in reducing falls, freezing of gait (FOG), and improving gait asymmetry. Methods: Twenty-eight participants with idiopathic PD and treatment-resistant FOG underwent 18 sessions of SBTM and TM training. Primary outcome was the incidence of falls 3 months after training, and secondary measures included spatiotemporal gait variables (treadmill and over-ground), motor scores, and performance on FOG and balance questionnaires. Results: Treadmill training improved falls regardless of intervention (SBTM: P < 0.05; TM: P < 0.01), although benefits were not sustained at 3 months. SBTM did not meet the a priori 20% superiority threshold for falls prevention. Asymmetry index, temporal asymmetry, and stance time (P <= 0.01 in both groups) reduced after training. Swing time increased after training with both interventions (P <= 0.01). FOG and ABC scores also improved (P <= 0.01 in both groups), however, these improvements were not sustained at 3 months. Cadence and over-ground asymmetry index improved with both interventions (P <= 0.01), although only reduced cadence was sustained at 3 months (P = 0.05). Other over-ground parameters including gait velocity, stride length, double-support time improved with TM training only. Conclusions: SBTM was not superior to TM training in improving incidence of falls. Both interventions improved FOG and spatiotemporal gait parameters, although TM training translated better to over-ground walking.