Disorders of posture, balance, and gait in Parkinson's disease.

Disorders of movement function related to posture, balance, and gait are common occurrences for many persons with Parkinson's disease. Numerous studies have identified a broad variety and heterogeneous distribution of postural and locomotor changes. These alterations are often associated with diminished functional ability, poor prognosis, and frequent falls. Present pharmacologic management appears to have a limited influence on postural instability and associated falls, and, despite anecdotal information, there is scant information on the therapeutic effectiveness of physical interventions aimed at enhancing these functions. Future advances would likely be facilitated by: (1) determining the nature and extent of the specific involvement of postural and locomotor control mechanisms; (2) coalescing findings on motor control processes with clinical information to develop rehabilitation approaches that target specific motor manifestations; and (3) conducting long-term clinical trials to demonstrate the efficacy of interventions.