Abstract
Purpose of this study was to characterize side-to-side differences in quadriceps, hamstrings strength, and quadriceps activation in individuals with Parkinson disease (PD). Participants were individuals with PD (n = 17) with Unified Parkinson's Disease Rating Scale motor scores ranging from 9.5 to 61.0. Paired t tests compared strength and muscle activation between limbs for all individuals. The stronger quadriceps was 15.2% stronger (P < .001) and the stronger hamstring was 12.9% stronger (P = .001). Side-to-side differences in quadriceps activation was 18.9%, but insignificant (P = .072). No pattern explained side-to-side differences. Muscle strength asymmetry is variable, but present across a range of PD disease severity, which emphasizes the importance of a detailed clinical examination.