Effects of foam rolling on hip pain in patients with hip osteoarthritis: a retrospective propensity-matched cohort study

Background Foam rolling is a self-applied massage using a foam roller that has gained popularity for treatment of muscle soreness. However, its efficacy for improving hip pain in patients with hip osteoarthritis remains unclear. Objective To investigate the effects of foam rolling on hip pain in patients with hip osteoarthritis. Methods In this retrospective propensity-matched cohort study, medical records of outpatients between January 2017 and March 2019 were reviewed. Of these, 115 patients with hip osteoarthritis were divided into foam rolling or non-foam rolling groups based on home exercises. Both groups were propensity-score matched (1:1) for age, sex, body mass index, Kellgren and Lawrence grade, and visual analog scale (VAS) of hip pain at baseline. The primary outcome was the hip pain-VAS. Effects of interventions on the hip pain-VAS were examined using a split-plot design variance analysis. Results After matching, both groups comprised 37 patients each. No significant differences were observed in baseline characteristics and outcome measurements between the matched groups. A statistically significant interaction was seen between the effects of time and group for hip pain-VAS (F [1, 72] = 31.874, interaction:P< .001, eta(2) = 0.307). Hip pain-VAS was improved more effectively in the foam rolling group than those in the non-foam rolling group (P< .001). Thirty-four (92%) patients in the foam rolling group, compared to 15 (41%) in the non-foam rolling group, showed a >= 32% (minimal clinically important difference) improvement in hip pain-VAS. Conclusion These results suggested that foam rolling was an effective intervention for improving hip pain in patients with hip osteoarthritis.