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

背景
腰痛（Low back pain）在孕妇群体中患病率极高，但目前仍缺乏有效的治疗方案相关证据。监督式运动（Supervised exercise）——包括陆上或水中运动形式——已被证实可改善腰痛，但尚无试验探究无监督水中运动方案（unsupervised water exercise program）对腰痛的干预效果。本研究旨在评估无监督水中运动方案对健康孕妇腰痛强度及病假天数的影响。

方法
本项随机对照平行组试验（randomised, controlled, parallel-group trial）共纳入516名健康孕妇，将其随机分配至无监督水中运动组（每周2次，持续12周）或标准产前保健组。纳入标准为：年龄≥18岁的健康孕妇，单胎妊娠，孕周为16~17周。主要结局指标为妊娠32周时通过腰痛评定量表（Low Back Pain Rating scale）评估的腰痛强度。次要结局指标包括自我报告的病假天数、腰痛相关残疾情况（采用罗兰·莫里斯残疾问卷（Roland Morris Disability Questionnaire）评估）以及自我评估的总体健康状况（采用EQ-5D与EQ-VAS评估）。

结果
妊娠32周时，水中运动组的腰痛强度显著低于对照组：水中运动组评分为2.01（95%置信区间（95% CI）：1.75~2.26），对照组为2.38（95% CI：2.12~2.64）（均数差=0.38，95% CI：0.02~0.74，P=0.04）。两组的病假天数无显著差异（中位数均为4，P=0.83），腰痛相关残疾程度及自我评估的总体健康状况亦无统计学差异。妊娠32周时，水中运动组报告无腰痛的孕妇比例呈升高趋势（21% vs. 14%，P=0.07）。

结论
无监督水中运动可使健康孕妇的腰痛强度在统计学上显著降低，但该结果大概率不具备临床意义。该方案未对病假天数、腰痛相关残疾程度及自我评估的健康状况产生显著影响。

试验注册
ClinicalTrials.gov NCT02354430