Reliability of gait analysis using wearable sensors in patients with knee osteoarthritis.

The aim of this study was to determine the test-retest reliability of linear acceleration waveforms collected at the low back, thigh, shank, and foot during walking, in a cohort of knee osteoarthritis patients, by applying two separate sensor attitude correction methods (static attitude correction and dynamic attitude correction). Linear acceleration data were collected on the subjects׳ most affected limb during treadmill walking on two separate days. Results reveal all attitude corrected acceleration waveforms displayed high repeatability, with coefficient of multiple determination values ranging from 0.82 to 0.99. Overall, mediolateral accelerations and the thigh sensor demonstrated the lowest reliabilities, but interaction effects revealed only mediolateral accelerations at the thigh and foot sensors were different than other axes and sensor locations. Both attitude correction methods led to improved reliability of linear acceleration waveforms. These findings suggest that while all sensor locations and axes display acceptable reliability in a clinical knee osteoarthritis population, the back and shank locations, and the vertical and anteroposterior acceleration directions, are most reliable.