Novel continuous passive motion device for self-treatment of chronic lower back pain: a randomised controlled study

Abstract Objective To evaluate the efficacy of a novel, angular, continuous passive motion device for self-treatment at home in patients with mild-to-moderate, non-specific, chronic low back pain (LBP). Design Prospective, randomised, waiting-list-controlled (WLC) trial. Setting Recruitment and assessment were conducted at the Koren Centre for Physical Therapy. Self-treatment was performed at home. Participants Thirty-six patients with a score ≤6 on the numeric rating scale (NRS) for pain were enrolled. Twenty-eight patients completed treatment. Interventions Participants were randomised to receive the Kyrobak (Radiancy, Hod-hasharon, Israel) at enrolment [immediate treatment (IT) group] or 3 weeks later (WLC group). Self-treatment was prescribed for 10 minutes, one to three times per day, for 3 weeks. The treatment period was followed by a 3-week follow-up period. Main outcome measures Primary outcome was self-reported pain level (NRS). Results Three weeks of self-treatment with the Kyrobak reduced pain levels significantly in the IT group compared with the WLC group {mean [standard deviation (SD)] ΔNRS score from baseline to post-treatment: IT group, 1.4 (1.5), 95% confidence interval (CI) 0.5 to 2.3; WLC group, −0.1 (2.2), 95% CI −1.1 to 1.2; effect mean difference 1.5}. This benefit was maintained over the follow-up period [from baseline to end of follow-up, mean (SD) ΔNRS score 1.1 (1.8), 95% CI 0.4 to 1.8]. Multi-linear regression analysis found that higher baseline pain resulted in greater pain reduction ( P = 0.003). Eighty-three percent of participants with a baseline NRS score >4.35 (threshold determined by logistic regression, P = 0.01) achieved the minimal important change criterion of ΔNRS score ≥2. Daily NRS score reduced gradually over the treatment period [regression slope −0.052 (0.01), 95% CI −0.07 to −0.03]. Conclusions Preliminary evidence suggests that the Kyrobak may be beneficial for short-term relief of non-specific, chronic LBP, particularly in participants with a moderate level of pain. A longer treatment period may lead to a further reduction in pain.