The relationship between urinary incontinence, pelvic floor muscle strength and lower abdominal muscle activation among women with low back pain

Purpose: This study aims to compare pelvic floor muscles (PFM) strength and lower abdominal muscle activation in women with low back pain (LBP) and urinary incontinence (UI) or without UI. Methods: Fifty-four women with LBP were assessed. PFM strength was assessed using the modified Oxford scale and lower abdominal muscle activation was evaluated using a pressure biofeedback unit. Lumbar disability and pain intensity were evaluated by self-reported questionnaires. The Mann-Whitney U-test was used to compare the two groups. A correlation analysis was performed between PFM strength and lower abdominal muscle activation and self-reported measures. Results: Our results showed that 31 presented with UI and 23 without. No statistically significant difference was found between groups in PFM strength (median values; with UI = 3; without UI = 3; p = .61) and in lower abdominal muscle activation capacity (median values; with UI = 9mmHg; without UI = 6mmHg; p = .40). PFM weakness was found in both groups. No significant correlation between the strength of PFM and other variables was found. Conclusion: In conclusion, women with LBP showed an insufficient strength of the PFM, regardless of the presence of UI. The degree of PFM strength was not related to lower abdominal muscle activation, lumbar disability or LBP characteristics.