Assessment of Pelvic-Lumbar-Thigh Biomechanics to Optimize The Childbirth Position: An \u201cIn Vivo\u201d Innovative Biomechanical Study

David Desseauve,Arnaud Decatoire,Henri Panjo,Fabrice Pierre,Patrick Lacouture,Anna Fernandez,Laetitia Fradet

doi:10.1038/s41598-019-52338-8

Abstract

The study aimed to assess the associations between the pelvis orientation, lumbar curve and thigh postures throughout pregnancy in a population of healthy women. Additionally, optimal mechanical birth conditions in terms of the pelvic inlet and lumbar curve were researched. The individuals’ posture was assessed with three-dimensional motion analysis and the lumbar curve with the Epionics SPINE system. The association between the hip joint angles (flexion and abduction), the pelvis external conjugate, and lumbar curve position was assessed with a generalized linear mixed model (GLMM) adjusted to individuals’ characteristics. Joint laxity was assessed with a modified Jobbin’s extensometer. For all of the subjects, hip flexion and hip abduction were significantly associated with the angle between the external conjugate and spine, with higher correlation in the multivariate regression model. The association between hip flexion and the lumbar curve was less significant in multivariate than univariate regression analysis. Optimal birth conditions were never reached. The findings contribute to the understanding of the association between the hip position (flexion and abduction), pelvic orientation, and lumbar curve adjusted for joint laxity in healthy pregnant women. They lay the groundwork for future research in the field of obstetrical biomechanics.

Highlights

Progress in movement analysis and its computationally derived methods has provided safe technological solutions that can be extrapolated to the analysis of the posture of a parturient woman[7]
Two participants were lost to follow-up between the 2nd trimester and 3rd trimester of pregnancy (TIP)
The association was higher for hip flexion (RC = 0.23, 95% confidence interval (CI) [0.21–0.25]) than for hip abduction (RC = 0.15, 95% CI [0.11–0.19])

Summary

Introduction

Progress in movement analysis and its computationally derived methods has provided safe technological solutions that can be extrapolated to the analysis of the posture of a parturient woman[7]. The best conditions combine the flattening of the lumbar hinge with a pelvic inlet plane perpendicular to the axis of foetal progression This interrelatedness between the “channel features” (pelvis and lumbar curve) and the progression of the “passenger” was previously hypothesized by Asphasie in ancient Greece, by Faraboeuf in the nineteenth century and, more recently, by Hainault et al.[9,10,11]. These pioneering studies were complemented by radiology-based findings by Gherman et al For the first time, this research assessed the effects of thigh flexion on the lumbar spine and the pelvis orientation throughout McRoberts manoeuvres[12]. Since joint laxity variations due to hormonal changes have been observed during pregnancy, laxity measures need to be obtained during the different stages of pregnancy[17]

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Conclusion