Parkinsonism and Related Disorders

Nearly all patients with Parkinson’s disease (PD) experience gait problems, often already in early disease stages, with clear worsening as the disease progresses. It would be helpful to have a simple and objective tool to quantify gait, both in the laboratory setting and in the patient’s own home environment. This could facilitate clinical decision making, or can be used as outcome measure in clinical trials. It is currently possible to provide very detailed assessments in the gait laboratory, for example using motion analysis systems. While accurate, such evaluations are also expensive, and not necessarily reflective of real-life performance. Moreover, the gait laboratory only documents walking impairments, but does not investigate the subject’s actual walking behavior. To address these limitations, ambulatory gait monitors have been introduced to quantify movements of the limbs or trunk during a prolonged time in daily life. In healthy subjects, ambulatory monitors can record spatiotemporal gait parameters such as stride cycles, numbers of left and right steps, step length and walking speed over ground walking [1]. Later work also concentrated on applying activity monitors in patients with PD [2–4]. However, none of these studies evaluated the ability of activity monitors to estimate walking distances in patients with PD. We therefore evaluated the ability of a simple activity monitor (based on tri-axial accelerometers) to estimate walking distance in PD.