Efficacy of pulsed electromagnetic field on pain and physical function in patients with low back pain: A systematic review and meta-analysis

Objective To assess the effectiveness of pulsed electromagnetic field (PEMF) on pain and physical function in patients with low back pain. Data sources A search of PubMed, Embase, Cochrane Library, and Web of Science was conducted up to December 2021. Methods We included randomized controlled trials that investigated the effectiveness of PEMF in patients with low back pain. The primary outcome was pain intensity and the secondary outcome was physical function, both were evaluated by assessment scales. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated for the summary statistics analysis. The registration number of this systematic review in PROSPERO is CRD42020213829. Results Fourteen trials involving 618 participants were included. The PEMF treatment showed more significant pain alleviation than placebo or other therapy alone in patients with low back pain (SMD = -1.01, 95% CI -1.42 to -0.6, P < 0.001, I-2 = 31%; SMD = -0.36, 95% CI -0.62 to -0.11, P = 0.005, I-2 = 37%, respectively.) In addition, a significant difference in pain alleviation was observed in patients with chronic low back pain (SMD = -0.6, 95%CI - 0.94 to -0.25, p < 0.001, I-2 = 67%), whereas no significant difference was observed in patients with acute low back pain (SMD = -0.46, 95%CI - 0.99 to 0.07, p = 0.09, I-2 = 0%). PEMF did not improve physical function compared with the control treatment (SMD = -0.45, 95% CI - 0.98 to 0.07, p = 0.09, I-2 = 86%). Conclusion PEMF is beneficial for alleviating pain in patients with chronic low back pain despite having no advantage in improving physical function.