Studying the changes of the lumbar and thoracic curvatures and pelvic tilt inclinations during pregnancy in primigravida women

  • Sedigheh Koohkan AbbasRahimi
  • Abbas Rahimi
  • Mehri Ghasemi
  • Sedigheh-Sadat Naimi
  • Alireza Akbarzadeh Baghban


Background and Aim: Research show extensive physiological and postural changes in pregnancy, particularly during the first pregnancy. These changes are in sense of balance, neurological and mechanical forms. The precise changes in postures of each parts of the body in primigravida women are still ambiguous. The current study aims to find out spinal and pelvic changes in these women in static standing.

Materials and Methods: The lumbar and thoracic curves and pelvic inclination angles of thirty primigravida women (age 25±1, BMI 23±1) in the first, second and third trimesters (Weeks 10, 21 and 32 of pregnancy) were recruited in this cohort study and were compared with 18 age-BMI matched non- pregnant women (age 24±1, BMI 23±1) in a static standing posture.  The curvatures were measured with use of a flexible ruler and the pelvic inclination angle was measured by a pelvic inclinometer device. Before starting the main study, the reliability and repeatability of the flexible ruler and pelvic inclinometer were confirmed in this study (ICC>0.87).

Results: An increased curvature and inclination angles were shown simultaneously while pregnancy progresses. The results showed a significant increased lumbar and thoracic curvature angles in pregnant group only during the first and second trimesters (P<0.05). However, pelvic inclination angles significantly increased during all trimesters of the pregnancy (P<0.05).

Conclusion: The present study showed significant increases in both lumbar and thoracic curves (Sway back) and an increased pelvic tilt during pregnancy period. The results might help clinicians for prescribing suitable exercises during pregnancy and after the delivery. More research is recommended in this area.

Key Words: Primigravida women, Spinal curvatures, Pelvic tilt, Flexible ruler, Pelvic inclinometer.