The effects of an unsupervised water exercise program on low back pain and sick leave among healthy pregnant women – A randomised controlled trial

BACKGROUND Low back pain is highly prevalent among pregnant women, but evidence of an effective treatment are still lacking. Supervised exercise-either land or water based-has shown benefits for low back pain, but no trial has investigated the evidence of an unsupervised water exercise program on low back pain. We aimed to assess the effect of an unsupervised water exercise program on low back pain intensity and days spent on sick leave among healthy pregnant women. METHODS In this randomised, controlled, parallel-group trial, 516 healthy pregnant women were randomly assigned to either unsupervised water exercise twice a week for a period of 12 weeks or standard prenatal care. Healthy pregnant women aged 18 years or older, with a single fetus and between 16-17 gestational weeks were eligible. The primary outcome was low back pain intensity measured by the Low Back Pain Rating scale at 32 weeks. The secondary outcomes were self-reported days spent on sick leave, disability due to low back pain (Roland Morris Disability Questionnaire) and self-rated general health (EQ-5D and EQ-VAS). RESULTS Low back pain intensity was significantly lower in the water exercise group, with a score of 2.01 (95% CI 1.75-2.26) vs. 2.38 in the control group (95% CI 2.12-2.64) (mean difference = 0.38, 95% CI 0.02-0.74 p = 0.04). No difference was found in the number of days spent on sick leave (median 4 vs. 4, p = 0.83), disability due to low back pain nor self-rated general health. There was a trend towards more women in the water exercise group reporting no low back pain at 32 weeks (21% vs. 14%, p = 0.07). CONCLUSIONS Unsupervised water exercise results in a statistically significant lower intensity of low back pain in healthy pregnant women, but the result was most likely not clinically significant. It did not affect the number of days on sick leave, disability due to low back pain nor self-rated health. TRIAL REGISTRATION ClinicalTrials.gov NCT02354430.