Effect of the WISH-type Hip Brace on Postural Control in Patients with Osteoarthritis of the Hip: Evaluation using the Cross Test

Background: The WISH-type S-form brace, a type of hip brace, has been shown to improve hip function, functional mobility and gait biomechanics in patients with osteoarthritis of the hip. Aims: The effects of the brace on postural control were evaluated. Methods: The Cross test using a force plate was performed. Results: The hip brace showed a direct beneficial effect of improving the maximum excursions of the center of pressure in both the medial-lateral and anterior-posterior directions. The performance in the Cross test of patients using the brace improved in the later phase, indicating an indirect effect of the brace. Interestingly, the brace also exerted a direct effect on the muscle strength of the braced leg in both hip flexion and adduction. Conclusions: Augmentation of the power output of the adductor and flexor muscles by the brace may support the moment required for resistance against the upper body mass leaning on the braced side and backward, which may allow the excursions to be augmented.