Knee bracing for medial compartment osteoarthritis: effects on proprioception and postural control.

OBJECTIVE To evaluate the effects of a functional knee brace specifically designed for patients with varus gonarthrosis on measures of proprioception and postural control. SUBJECTS Fourteen men and six women (aged 59+/-9 yr) with measurable varus alignment and osteoarthritis of the knee medial compartment. METHODS Proprioception was assessed in the sitting position using an isokinetic dynamometer and was quantified as the ability to replicate target knee-joint angles. Postural control was assessed with a force platform using tests of single-limb standing balance performed, while the patient was standing on a stable surface and standing on foam, and was quantified as the total length of the path of the centre of pressure. All tests were performed with and without the patient's own custom-fit valgus brace. RESULTS Proprioception was significantly improved following application of the brace [mean difference=0.7 degrees, 95% confidence interval (CI)=0.2 to 1.1 degrees ). Postural control was not significantly affected by the use of the brace during the stable surface test (mean difference=2.6 cm, 95% CI=-4.3 to 9.5 cm) or the foam surface test (mean difference=0.9 cm, 95% CI=-7.5 to 9.4 cm). CONCLUSION Although enhanced proprioception may be partially responsible for reported improvements with the use of a brace, the present findings call into question the functional importance of the small changes observed.