Back pain during pregnancy and its relationship to anthropometric biomechanical parameters

Abstract

Numerous studies aiming at testing the relationship between back pain occurrence during pregnancy and demographics, such as parity, age and total body mass, have found conflicting evidence for parity and age, and weak evidence for the total body mass. The aim of this study was to test the possible relationship between anthropometric biomechanical parameters and disability during pregnancy. Anthropometric data were gathered using a stereophotogrammetric method described by Jensen. Data of interest were trunk mass and moments of inertia. The influences of total body mass, age and weight gain on level of disability were also investigated. The latter was quantified using the Oswestry Disability Index (ODI), and painful regions were recorded on a pain drawing. Data were collected at mid- and late-pregnancy, 20 and 34 weeks respectively. Correlations between ODI and other parameters were assessed using the Spearman correlation for ranked data. This test was first performed on the whole mid-pregnancy and late pregnancy samples regardless of pain site. Correlation coefficients were then computed again for sub-samples stemming from the pain drawing data. A positive relationship was found between anthropometric parameters and ODI in the small mid-pregnancy sample, and a negative one has been found in the late pregnancy sample. More specific results appeared for the sub-samples with respect to pain regions. A strong relationship was observed between biomechanical parameters and ODI in the mid-pregnancy low back pain sub-sample. The upper back pain mid-pregnancy sub-sample showed no correlations and the sacroiliac pain group presented rather weak or no relationship with disability. Our findings suggest different etiologies for different kinds of back pain and underline the influence of anthropometric parameters in low back pain observed in pregnancy. Pregnant women suffering from low back pain should be advised to be aware of and control their weight gain as it may have a relationship to lower back pain symptoms. Samples studied here were rather small and further investigation is required to confirm these findings.