Hip-focused physical therapy versus spine-focused physical therapy for older adults with chronic low back pain at risk for mobility decline (MASH): a multicentre, single-masked, randomised controlled trial.

Background: Previously, we identified a population of older adults with chronic low back pain, hip pain, and hip muscle weakness who had worse 12-month low back pain and functional outcomes than age-matched adults with only low back pain, indicating an increased risk for future mobility decline. We sought to determine whether tailored, hip-focused physical therapy reduced pain and functional limitations in this high-risk population compared with non-tailored, spine-focused physical therapy.

Methods: We did a multicentre, single-masked, randomised controlled trial at three research-based sites in the USA. We recruited older adults (aged 60-85 years) with hip pain and weakness who reported moderate low back pain intensity at least half the days in the last 6 months. Patients were randomly assigned to hip-focused physical therapy or spine-focused physical therapy using permuted blocks with random block size, stratified by site and sex (ie, male or female). The primary outcomes were self-reported disability using the Quebec Back Pain Disability Scale (QBPDS) and performance-based 10-Meter Walk Test (10MWT) at 8 weeks. All analyses were done in the intention-to-treat population. Adverse events were collected by study staff via a possible adverse event reporting form and then adjudicated by site investigators. This trial was registered with ClinicalTrials.gov, NCT04009837.

Findings: Between Nov 1, 2019, and April 30, 2022, 184 participants were randomly assigned to receive hip-focused (n=91) or spine-focused physical therapy (n=93) interventions. The mean age was 70·7 (SD 6·2) years. 121 (66%) of 184 participants were women, 63 (34%) were men, and 149 (81%) were White. At 8 weeks, the mean between-group difference on the QBPDS was 4·0 (95% CI 0·5 to 7·5), favouring hip-focused physical therapy. Both groups had similar, clinically meaningful gait speed improvements (10MWT) at 8 weeks (mean difference 0·004 m/s [95% CI -0·044 to 0·052]). No serious adverse events were related to study participation.

Interpretation: Tailored hip-focused physical therapy demonstrated greater improvements in low back pain-related disability at 8 weeks. However, both hip-focused physical therapy and spine-focused physical therapy produced clinically meaningful improvements in disability and function for this high-risk population at 6 months. These findings warrant further investigation before clinical implementation.

Funding: US National Institute on Aging of the National Institutes of Health.