Trauma is the major cause of problems with the pelvis.
Car crashes, ski injuries and other high speed impacts are the most likely factors.
Disruption to the symphasis pubis and SIJ are painful and often hard to settle.
Pregnancy and child birth are the other common causes of pain and injury to the pelvis. From around 12 weeks of pregnancy to around 12 weeks after breast feeding is finished the female body releases a hormone that relaxes the ligaments throughout the body to allow maximum motion in the pelvis during birth. Commonly the joints of the pelvis increase their mobility at different rates which can be compounded by the position of the baby and leading to pain.