Acceleration-based motion analysis as a tool for rehabilitation: exploration in simulated functional knee limited walking conditions.

OBJECTIVE: The aim of this study was to investigate the ability of acceleration-based gait analysis to differentiate between normal gait and different simulated functional knee limitations of increasing severity.
DESIGN: Gait of 48 healthy subjects was measured under four different walking conditions. Gait parameters (e.g., speed and asymmetry) were derived from trunk accelerations. Subjects walked a 20-m distance under four conditions: normal, simulated limited knee extension, simulated limited knee flexion, and simulated arthrodesis. The functional knee limitations were simulated using an adjustable knee brace on the right leg.
RESULTS: Acceleration-based gait analysis detected acute gait changes (i.e., speed, step length, step duration, cadence, vertical displacement, asymmetry, and irregularity) during the simulated functional knee limitations with high repeatability. The degree of change depended on the severity of the limitation, with the more severe limitations producing bigger changes in gait and the relative changes comparing well with literature values measured with laboratory-based motion analysis.
CONCLUSIONS: Acceleration-based gait analysis is sensitive for different walking conditions. The easy and fast use, the production of objective gait characteristics, and the ability to differentiate functional knee limitations suggest its suitability for clinical rehabilitation.