Background: Primary dysmenorrhea is defined as menstrual pain that is not associated with macroscopic pathology .It is typically occurs in the first few years after menarche and affects as many as 50% of post pubertal females .Purpose: of this study was to investigate the relationship between lumbopelvic alignment and severity of primary dysmenorrhea. Methods: Fifty adolescent female suffering from primary dysmenorrhea; their ages ranged from 15 to 25 years old and their BMI ranged from 19.5 to 27.9 Kg/m2 ,were selected from outpatient clinics of Gynecology in One Day Surgeries Hospital, Cairo, Egypt. They were assigned into 2groups equal in number according to severity of pain. Group (A);(n=25)suffered from mild primary dysmenorrhea and group (B);(n=25) suffered from severe primary dysmenorrhea. Evaluation of severity of primary dysmenorrhea was done for all participants in both groups (A&B) using Visual Analogue Scale (VAS) and Verbal multidimensional scoring system (VMSS). Radiography and Surgimap software program were used to assess and analyze lumbopelvic alignment in the form of three angles (pelvic tilt , sacral slope ,lumbar lordosis).Measurement was done for one shot for participants in both groups (A&B). Results; showed that there was a statistical significant increase in the mean values of sacral slope in group (B) than group (A),and a statistical significant decrease in the mean values of pelvic tilt in group (B)than group (A) (P=0.018), (P=0.047) respectively while there was no statistical significant difference in mean values of lumbar lordotic angle between the two groups(A&B)(P=0.547).Also, there was a statistical significant inverse correlation between sacral slope and pelvic tilt in both groups (A&B) (p=0.010) . There was a statistical significant direct correlation between sacral slope and lumbar lordotic angle in both groups (A&B) (p=0.001). Conclusion: It could be concluded that lumbopelvic misalignment could increase intensification ofdysmenorrhic pain and might be associated with severe degree of primary dysmenorrhea.
