Effects of a hip brace on biomechanics and pain in people with femoroacetabular impingement

Abstract

Objectives: This study evaluates whether hip bracing in patients with femoroacetabular impingement (FAI) (a) immediately reduces range of hip internal rotation, flexion, adduction, and pain during functional tasks; and (b) improves patient-reported outcomes when worn daily over 4 weeks.

Design: Within-participant design followed by a case series.

Methods: Twenty-five adults with symptomatic FAI underwent 3D kinematic assessment with and without a hip brace during single-leg squat, double-leg squat, stair ascent, and stair descent. A subset of this population (n=17) continued to wear the brace daily for 4-weeks. A linear mixed statistical model was used to assess pain and kinematic differences between the braced and unbraced conditions at baseline testing. Patient-reported outcomes (NRS pain, iHot-33 and HAGOS questionnaires) at 4-weeks were compared to baseline using paired t-tests.

Results: Bracing resulted in significant but small reductions in peak hip flexion ranging between 5.3° (95% CI 0.8°-9.7°) and 5.6° (95% CI 1.1°-10.0°), internal rotation ranging between 2.5° (95% CI 0.6°-4.4°) and 6.4° (95% CI 4.5°-8.2°), and adduction ranging between 2.2° (95% CI 0.5°-3.8°) and 3.3° (95% CI 1.6°-5.0°) during all tasks, except flexion during single-leg squat, compared with the unbraced condition; pain was not significantly improved with the brace. Bracing over four weeks did not significantly change patient-reported outcomes.

Conclusions: Bracing subtly limited impinging hip movements during functional tasks, but did not immediately reduce pain or improve patient-reported clinical outcomes after 4 weeks in a young adult cohort with long-standing FAI.

Keywords: Biomechanics; Brace; Conservative therapy; FAI; Femoroacetabular impingement; Orthosis.