“Stepping Up” Activity Poststroke: Ankle-Positioned Accelerometer Can Accurately Record Steps During Slow Walking

TLDR

Physical activity is low after stroke, and although activity monitors can motivate exercise, most are inaccurate at slow walking speeds. This study evaluated the accuracy of a single accelerometer in measuring steps of community‑dwelling stroke survivors. In a cross‑sectional design, 43 participants wore waist and ankle accelerometers while walking at seven speeds (0.3–0.9 m/s) and their step counts were compared to video recordings, though some could not complete the faster speeds. The waist‑mounted device had >10 % error at all but the fastest speeds and often recorded zero steps at 0.3–0.5 m/s, whereas the ankle‑mounted device maintained ≤10 % error from 0.4 to 0.9 m/s, suggesting ankle placement provides accurate feedback for slow post‑stroke walking.

Abstract

Background As physical activity in people poststroke is low, devices that monitor and provide feedback of walking activity provide motivation to engage in exercise and may assist rehabilitation professionals in auditing walking activity. However, most feedback devices are not accurate at slow walking speeds. Objective This study assessed the accuracy of one accelerometer to measure walking steps of community-dwelling individuals poststroke. Design This was a cross-sectional study. Methods Two accelerometers were positioned on the nonparetic waist and ankle of participants (N=43), and walking steps from these devices were recorded at 7 speeds (0.3–0.9 m/s) and compared with video recordings (gold standard). Results When positioned at the waist, the accelerometer had more than 10% error at all speeds, except 0.8 and 0.9 m/s, and numerous participants recorded zero steps at 0.3 to 0.5 m/s. The device had 10% or less error when positioned at the ankle for all speeds between 0.4 and 0.9 m/s. Limitations Some participants were unable to complete the faster walking speeds due to their walking impairments and inability to maintain the requested walking speed. Conclusions Although not recommended by the manufacturer, positioning the accelerometer at the ankle (compared with the waist) may fill a long-standing need for a readily available device that provides accurate feedback for the altered and slow walking patterns that occur with stroke.