Besteht ein Zusammenhang zwischen Rückenschmerz und der Stabilität der lumbalen Wirbelsäule in der Schwangerschaft?

Abstract

During pregnancy approximately 50% of women suffer from low back pain (LBP), which significantly affects their everyday life. The pain could result in chronic insomnia, limit the pregnant women in their ability to work and produce a reduction of their physical activity. The etiology of the pain is still critically discussed and not entirely understood. In the literature different explanations for LBP are given and one of the most common reasons is the anatomical changes of the female body during pregnancy; for instance, there is an increase in the sagittal moments because of the enlarged uterus and fetus and the occurrence of hyperlordosis.The aim of this study was to describe how the anatomical changes in pregnant women affect the stability and the moments acting on the lumbar spine with the help of a simplified musculoskeletal model.A two-dimensional musculoskeletal model of the lumbar spine in the sagittal plane consisting of five lumbar vertebrae was developed. The model included five centres of rotation and three antagonistic pairs of paraspinal muscles. The concept of altered acting torques during pregnancy was explored by varying the geometrical arrangements. The situations non-pregnant, pregnant and pregnant with hyperlordosis were considered for the model-based approach. These simulations were done dependent on the stability of the erect posture and local countertorques of every lumbar segment.In spite of the simplicity of the model and the musculoskeletal arrangement it was possible to maintain equilibrium of the erect posture at every lumbar spinal segment with one minimum physiological cross-sectional area of all paraspinal muscles. The stability of the musculoskeletal system depends on the muscular activity of the paraspinal muscles and diminishing the muscular activity causes unstable lumbar segments.The relationship between the non-pregnant and the pregnant simulations demonstrated a considerable increase of acting segmental countertorques. Simulating an increased lordosis for the pregnant situation in the sagittal plane substantially reduced these acting countertorques and therefore the demand on the segmental muscles.It is assumed that hyperlordosis is a physiological adaptation to the anatomical changes during pregnancy to minimize the segmental countertorques and therefore the demand on the segmental muscles.Further, it can be expected that an enhanced muscle activity caused by selective activity of lumbar muscles increases the stability of the lumbar spine and may improve the situation with LBP during pregnancy.

Prevalence of lumbopelvic pain during pregnancy: A systematic review and meta‐analysis of cross‐sectional studies

“…Increased motion in the pelvic joints diminishes the efficiency of load transmission and increases shear forces across the joints, resulting in pelvic girdle pain in pregnant women 63 . Additionally, there is an increase in the sagittal moment due to the enlarged fetus and uterus, resulting in hyperlordosis 64 . One study found that pregnant women with pelvic girdle pain had lower back flexor endurance values than those without pain 65 .…”

“… 63 Additionally, there is an increase in the sagittal moment due to the enlarged fetus and uterus, resulting in hyperlordosis. 64 One study found that pregnant women with pelvic girdle pain had lower back flexor endurance values than those without pain. 65 A case–control study showed that pregnant women adapted to their patterns of lumbar motion and erector spinae activity during flexion and extension.…”

Atraumatic Sacral Fracture in Late Pregnancy: A Case Report

“…14 To compensate for the increased load, most mothers will adopt an exaggerated lumbar lordosis while standing. 15 As the lumbar spine moves into greater extension, the sacrum moves into greater nutation, 16 and as a result, the compression loads acting on the SIJ when in upright postures are increased.…”

Spinal lordosis optimizes the requirements for a stable erect posture

“…Bipedalism and lumbar lordosis are often regarded as a cause of low back pain, through the increased spinal shearing forces and increased risk of spondylolisthesis [4,8,16,29,30]. In this respect it is of utmost importance to understand the function of lumbar lordosis.…”