Abstract
Introduction
Wearable sensors are promising tools for fast clinical gait evaluations in individuals with osteoarthritis (OA) of the knee and hip. However, gait assessments with wearable sensor are often limited to relatively simple straight-ahead walking paradigms. Parameters reflecting more complex and relevant aspects of gait, including dual-tasking, turning, and compensatory upper body motion are often overlooked in literature. The aim of this study was to investigate turning, dual-task performance, and upper body motion in individuals with knee or hip OA in addition to spatiotemporal gait parameters, taking shared covariance between gait parameters into account.
Methods
Gait was compared between individuals with unilateral knee (n=25) or hip (n=26) OA scheduled for joint replacement, and healthy controls (n=27). For 2 minutes, subjects walked back-and-forth a 6 meter trajectory making 180 degree turns, with and without a secondary cognitive task. Gait parameters were collected using four inertial measurement units on feet, waist, and trunk. To test if turning, dual-tasking, and upper body motion had added value above common spatiotemporal parameters, a factor analysis was conducted. Standardized mean differences were computed for the comparison between knee or hip OA and healthy controls. One gait parameter was selected per gait domain based on factor loading and effect size for the comparison between OA groups and healthy controls.
Results
Four independent domains of gait were obtained: speed-spatial, speed-temporal, dual task cost, and upper body motion. Turning parameters were part of the speed-temporal domain. From the gait domains that were obtained, stride length (speed-spatial) and cadence (speed-temporal) had the strongest factor loadings and effect sizes for both knee and hip OA, and lumbar sagittal range of motion (upper body motion) for hip OA only. Although dual-task cost was an independent domain, it was not sensitive to knee or hip OA.
Conclusions
Stride length, cadence, and lumbar sagittal range of motion were non-redundant and sensitive gait parameters, representing (compensatory) gait adaptations in individuals with knee or hip OA. Turning or dual-task parameters had limited additional value for evaluating gait in knee and hip OA, although dual-task cost constituted a separate gait domain. These findings hold promise for objective gait assessments in the clinic using wearable sensors. Future steps should include testing responsiveness of these gait domains to interventions aiming to improve mobility, including knee and hip arthroplasty.
