Article

Wearable, consumer-grade activity trackers have become widely
available as a means of monitoring physical activity in the form of step counts.
However, step counts may not be accurate in persons with Parkinson disease (PD)
due to atypical gait characteristics. Objective:
This study aimed to investigate
the accuracy of 4 consumer-grade activity trackers in individuals with PD while
ambulating during continuous and discontinuous walking tasks. Design: This study
used a cross-sectional design. Methods: Thirty-three persons with PD (Hoehn &
Yahr stages 1-3) donned 4 models of activity trackers on the less affected side
of their bodies. Participants performed 2 continuous walking tasks (2-minute walk
tests at comfortable and fast speeds) and 2 discontinuous walking tasks (a
simulated household course and an obstacle negotiation course) in an outpatient
setting. Bland-Altman plots and intraclass correlation coefficients [ICC(2,1)]
were computed as a measure of agreement between actual steps taken (reference
standard: video recording) and steps recorded by each tracker. Results: The
accuracy of the activity trackers varied widely, with ICCs ranging from -0.03 to
0.98. Overall, the most accurate device across all tasks was the Fitbit Zip, and
the least accurate was the Jawbone Up Move during the simulated household course.
All activity trackers were more accurate for continuous walking tasks compared
with discontinuous walking tasks. Waist-mounted devices were more accurate than
wrist-mounted devices with continuous tasks. Bland-Altman plots revealed that all
activity trackers underestimated step counts. Limitations: All walking tasks were
measured over relatively short distances. Conclusions: In persons with
mild-to-moderate PD, waist-worn activity trackers may be prescribed to monitor
bouts of continuous walking with reasonable accuracy; however, activity trackers
have little utility in monitoring discontinuous walking common in household
settings.

Langue : ANGLAIS