Citation

De Ridder R, De Blaiser C. Gait Posture 2019; 70: 30-32.

Affiliation

Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.

Copyright

(Copyright © 2019, Elsevier Publishing)

DOI

10.1016/j.gaitpost.2019.02.009

PMID

30798092

Abstract

BACKGROUND: The use of activity trackers has been proposed in rehabilitation where resuming physical activity is deemed crucial, e.g. after total knee arthroplasty (TKA). As patients initially often walk with crutches, it is of importance that clinicians can rely on the information provided by activity trackers. RESEARCH QUESTION: To determine concurrent validity of 2 activity trackers for step count, positioned on different locations on the body during gait with crutches.

METHODS: Thirty healthy participants performed normal gait and gait with one crutch and two crutches over a distance of 400 m while wearing a Garmin Vivofit 3 and Nokia Go on both wrists and both sides at the waist (only Nokia Go). The gold standard was manual step count. Inter-device reliability (within brand) was assessed by calculating Intraclass Correlation Coëfficients (ICC) and concurrent validity was determined by performing paired sample t-tests, ICC and Bland-Altman Plots with % bias and 95% CI Limits of Agreement (LoA).

RESULTS: During normal gait, both the Nokia and Garmin showed good to excellent inter-device reliability (ICC > 0.75). Both devices showed concurrent validity compared to manual step count, with slightly better results for the Garmin compared to the Nokia at the wrist (% bias = respectively 0.0% and -1.4% with 95% CI LoA: respectively -1.7%;1.7% and -8.6%;5.8%; ICC: respectively 0.995 and 0.859). During gait with crutches, however, overall 95% CI of LoA were beyond clinically acceptable differences and ICC values with the gold standard were poor. Therefore, notwithstanding a sometimes reported small average % bias, validity of the activity trackers for step count during gait with crutches was not established, independent of tracker position. SIGNIFICANCE: Activity trackers showed no concurrent validity when monitoring step count during gait with crutches. This should be taken into account when implementing this technology in e.g. post-operative goal setting in patients with TKA.

Copyright © 2019 Elsevier B.V. All rights reserved.

Language: en

Keywords

Concurrent validity; Gait; Rehabilitation; Reliability; Wearable sensor technology