Spinal posture and pelvic position during pregnancy: a prospective rasterstereographic pilot study

Despite the high prevalence of low back pain during pregnancy there is still a lack in the understanding of its aetiology. Changes of the spinal posture due to the anatomical changes of the pregnant body seem to be in part responsible for the back pain. In this pilot study we assessed the potential to accurately measure the spinal posture and pelvic position during pregnancy without any harmful radiation using a spine and surface topography system. Thirteen pregnant women were examined during the second and third trimester of their pregnancy, and postpartum. Twenty female, non-pregnant volunteers comprised the control group. The spinal posture and pelvic position were measured with a radiation-free spine and surface topography system. We found a significant increase in thoracic kyphosis during the course of pregnancy, but no increased lumbar lordosis. The lateral deviation of the spine also decreased significantly. However, we did not measure significant changes of the pelvic position during or after pregnancy. The results of our study show that pregnancy has an effect on the spinal posture, and that spine and surface topography can be used to measure these changes three-dimensionally and without any harmful radiation. In future studies this technique could allow to further evaluate the relationship between posture and low back pain during pregnancy, helping to understand the aetiology of low back pain in pregnancy as well as to identify methods for its prevention and treatment.