The effect of adding grade B hip mobilization to a muscle strengthening home exercise programme on pain, function, and range of movement in adults with symptomatic early-stage hip osteoarthritis: A pilot study for a randomized controlled trial

Abstract Objective A pilot study to investigate whether the addition of grade B mobilization to a muscle strengthening home exercise programme improves outcomes for patients with symptomatic early-stage hip osteoarthritis. Methods Twenty-three patients were randomized into either a home exercise group (n = 12) or grade B mobilization group (n = 11). Both groups carried out a muscle strengthening home exercise programme for 6 weeks. In addition, the grade B mobilization group received 6 weekly sessions of grade B hip mobilization (passive stretching techniques) and carried out stretches at home. Outcome measures included the visual analogue scale for pain, the Lower Extremity Functional Scale and goniometric measurement of hip flexion and medial rotation at baseline (week 1) and after the 6-week treatment period (week 7). Results Twenty-one participants (91%) completed the trial. Both groups showed improvement in all outcome measures. The change in pre-/post-treatment scores was significantly greater in the grade B mobilization group for pain (t(19) = 2.378, P = 0.03, large effect size d = 1.02) and passive hip flexion (t(19) = −4.192, P = 0.001, large effect size d = 1.80). No significant difference was found for function (t(19) = 0.444, P = 0.662, small effect size d = 0.20) or passive hip medial rotation (t(19) = −1.053, P = 0.305, moderate effect size d = 0.46). However, these results are inconclusive as this pilot study was underpowered. Discussion A worthwhile benefit may exist from the addition of grade B mobilization to a muscle strengthening home exercise programme, particularly with pain and passive hip flexion. This warrants further investigation. Although this pilot study demonstrated a feasible design, recommendations have been made for its development.