Is adding pelvic floor muscle training to an exercise intervention more effective at improving pain in patients with non-specific low back pain? A systematic review of randomized controlled trials.

Background: Pelvic floor muscles (PFM) contribute to optimal control of the lumbopelvic spine. PFM function appears altered in some people with nonspecific low back pain (LBP).

Objective: To systematically review if adding PFM training (PFMT) to another exercise intervention can be more effective at improving pain and function in people with nonspecific LBP than without PFMT.

Data Sources: The authors conducted a literature search on Medline, Embase, CINAHL, Cochrane Central and Web of Sciences up to October 2018. ELIGIBILITY CRITERIA: (1) Participants with nonspecific LBP; (2) additional PFMT to an exercise intervention; (3) comparison to the same intervention without PFMT; (4) included minimally one planned outcome; and (5) a randomized controlled trial. Two reviewers performed screening, data extraction (primary outcome; pain severity, secondary outcome; physical function) and risk of bias assessment.

Synthesis Methods: Meta-analysis was performed using mean difference and 95% confidence intervals.

Results: Six studies were included (n=200 participants). Participants with PFMT had lower pain severity in comparison with the group without PFMT (mean difference: -0.61, 95%CI [-0.91, -0.31], P<0.0001 and low heterogeneity: I=0%). Subgroup analysis shows significant effect for interventions lasting longer than 8-weeks. No difference was found for function. Overall risk of bias was unclear.

Limitations: Small groups and high heterogenicity limit our findings.

Conclusion: There is very low-quality evidence that there is a small benefit of adding PFMT to another exercise intervention on pain severity in nonspecific LBP. Longer duration for an integrated lumbopelvic exercise program including PFMT is likely to impact pain outcomes positively.

Prospero Registration: CRD42018114601.