Validity of the StepWatch Step Activity Monitor: preliminary findings for use in persons with Parkinson disease and multiple sclerosis.

Background: One goal for older adults with Parkinson disease (PD) and multiple sclerosis (MS) is community ambulation; however, the best way for clinicians to measure this has not been established. Self-report questionnaires rely on the participant's cognitive function and reporting accuracy, while the association between clinical timed walk tests and community ambulation may not be strong. Progress toward the identification of an appropriate clinical tool to measure strides in PD and MS populations is hampered by the lack of meaningful research and reference standards in this area.