Biomechanical analysis of gait in patients with painful osteoarthritis of the hip treated with WISH-type hip brace

Background A hip brace, the WISH-type S-form brace, improved hip function scores markedly in patients with painful hip osteoarthritis (OA). To evaluate the biomechanical effects of the brace, gait analysis using a force plate was performed. Methods For the gait of seven patients with this hip brace, characteristic parameters calculated from three-dimensional (i.e., vertical, forward, and medial) components of the floor reaction force were analyzed using a flat force plate. Results Gait analyses revealed several tendencies: a shorter time for one step, a stronger step, and a shift of the center of gravity of the body to the contralateral side. In particular, stronger vertical reaction force at the first peak in the early stance and earlier switch from backward to forward reaction force vectors were observed as effects of the hip brace, with statistically significant difference. Conclusions These biomechanical assessments suggest that abnormal gait in hip OA may be closer to normal gait in patients using this brace, although the deceleration and weighing-off effects, which are indicators useful for observing gait recovery, did not reach significance.