The effects of exercise on balance in persons with Parkinson's disease: a systematic review across the disability spectrum.

Parkinson's disease is a progressive neurodegenerative disorder that affects neurophysiologic function, movement abilities, and quality of life (QOL). Research examining the effects of exercise has suggested benefits related to a variety of outcomes; however, no reviews have synthesized research findings across the spectrum of disability. This project sought to systematically review studies that examined the impact of exercise interventions on balance outcomes for people with Parkinson's disease, within the categories defined by the World Health Organization in the International Classification of Functioning, Disability, and Health (ICF) model.