A study published online April 12 in the Journal of Disability and Rehabilitation determined that despite the potential of altered gait for people with lower-limb amputations, some consumer-grade wrist-worn activity monitors can accurately track over-ground walking.
Thirty-two participants with lower-limb prostheses (age = 49.7 ± 14.0 years, height = 176.1 ± 11.6 cm, weight = 87.8 ± 21.1 kg) were fitted with a Polar Loop, Fitbit Flex, MOVEBAND, Garmin Vivofit, and a Fitbit Charge on their right and left wrists as well as an Omron HJ-113 pedometer on the right and left hip. Participants walked 140m at a self-selected pace on an indoor flat surface.
The study showed no significant differences between any of the respective right and left monitors. When comparing step counts with actual step counts, Polar Loop, Fitbit Flex, and MOVEBAND were significantly lower than actual step counts, the study found. No significant differences, however, existed between the remaining monitors and actual step counts. Omron incurred the least error (0.6 percent), followed by Garmin Vivofit (1.3 percent) and the Fitbit Charge (3.6 percent). The greatest errors were found in the MOVEBAND (21.4 percent) and Polar Loop (13.1 percent), the study found.
A Bland-Altman plot suggested that the Garmin Vivofit appeared to have the least error along with tightest agreement among the wrist-worn activity monitors. The Garmin Vivofit also seemed to be the best option followed by the Fitbit Charge when considering wrist-worn activity monitors for assessing step counts in those using lower-limb prostheses, the study found.