The Relationship Between Abdominal Muscle Thickness and Lumbopelvic Pain During Pregnancy: a Cross-sectional Study

BACKGROUND: Lumbopelvic pain (LPP) is a very common cause of discomfort during pregnancy, but its etiology remains unclear. The association between abdominal muscle thickness and LPP in pregnant women has not been studied extensively, despite the significant abdominal changes that occur during pregnancy. This study aimed to examine the relationship between abdominal muscle thickness and LPP during pregnancy. METHODS: In this study, 49 pregnant women in their second trimester participated. The intensity of LPP was assessed using a numerical rating scale. Ultrasound imaging was used to measure the thickness of abdominal muscles, including the rectus abdominis, external oblique, internal oblique, and transversus abdominis muscles. Participants were classified into two groups, the LPP group and non-LPP group, and the abdominal muscle thickness was compared between the two groups. The statistical significance level was set at p<0.05. RESULTS: There were 24 and 25 participants in the LPP and non-LPP groups, respectively. Internal oblique (IO) thickness was significantly thinner in the LPP group than in the non-LPP group (5.4±0.2 mm vs. 6.1±0.2 mm; p=0.042). Multivariate logistic regression analysis showed that IO thickness was significantly associated with LPP (odds ratio, 0.516; 95% confidence interval, 0.284-0.935; p=0.019). CONCLUSIONS: This study suggested that LPP in second trimester pregnancy might be related to IO thickness. Further longitudinal studies are needed to understand the role of this muscle as an LPP risk factor for pregnant women.