Biomechanical Consequences of Motion-Restricting Lower Extremity Orthoses

A motion-capture study was performed to quantify changes in gait biomechanics associated with the use of locked knee-ankle-foot orthoses and rigid ankle-foot orthoses. Ground clearance, hip hiking, vaulting, circumduction, and temporospatial symmetry were compared for six able bodied subjects in four conditions: unbraced (control case), locked knee orthosis, locked knee-ankle-foot orthosis, and rigid ankle-foot orthosis. The results demonstrated significant increases in compensatory motions and gait asymmetry across all braced conditions, with the greatest changes seen in the KAFO case. Hip hiking was the most common gait strategy adopted across test cases, followed by circumduction, and then vaulting. Generalization of results was made difficult by heterogeneity of compensatory strategies adopted across test subjects. However, the data presented in this work and the method described herein may help to guide informed design and quantitative evaluation of future options in lower extremity bracing technology.Clinical Relevance- This work presents quantitative characterization of gait compensations in KAFO and AFO walking and describes a method for future assessments.