The Effects of Auditory Cues on Gait Mechanics in Parkinson's Disease

The purpose of this study is to determine how using auditory cues of a metronome and music at various frequencies impacts the gait mechanics in people with Parkinson's disease when walking over ground and on a treadmill. The investigators will enroll a total of 40 participants: 30 subjects with a diagnosis of Parkinson's disease (10 in Stage 1, 10 in Stage 2, and 10 in Stage 3) and 10 unimpaired subjects. Participants will complete 7 different treadmill walking conditions and overground walking conditions while the investigators measure step length, cadence, gait speed, and variability of movement.