Abstract
Background: Walking is often impaired in individuals with Parkinson's disease (PD). Overground locomotor training (OLT) promotes improved ambulation in this population, but its effects on walking propulsive force remain unknown. Research question: What are the effects of OLT on walking propulsive force in individuals with PD? Methods: A pre-experimental, pilot study, eleven participants (age 69.7 +/- 4.9 years) with mild to moderate PD (Hoehn & Yahr stage 1-3), completed 12 weeks of OLT. Outcomes included peak anterior ground reaction force (AGRF), AGRF rise time (RT), push-off impulse, and push-off duration; peak posterior ground reaction force (PGRF); single stance duration, center of mass (COM) to center of pressure (COP) distance at push-off; and walking speed. Pre- and post-intervention outcome differences were tested, and effect sizes were calculated. Results: Following OLT, significant differences were found for RT of the AGRF (p = .015, Cohen's d=.879), pushoff impulse (p = .026, Cohen's d=.789), push-off duration (p = .021, r = .697), single stance duration (p = .004, r = .857), and walking speed (p = .012, Cohen's d=1.18). No significant differences were found for peak AGRF, peak PGRF, or COM-COP distance. Significance: Results suggest OLT improved some aspects of walking ability in individuals with PD. Participants increased walking speed, spent less time in stance phase and push-off duration and decreased the RT of the AGRF. Participants exhibited a quicker, more powerful AGRF with no change in peak AGRF or push-off posture. The RT of the AGRF may be an important yet understudied determinant of propulsive force generation in this population.