The sacroiliac joint is the location in the body where the pelvis and the spine connect.
The term “sacroiliac” refers to the sacrum (the lower part of the spine) and the ilia (commonly known as the hip bones).
The joint is held together by ligaments and reinforced by muscle.
An injury to the SI joint typically involves an injury to the ligaments, which can cause the joint to move abnormally.
Muscles also play a key role in the function of the SI joint, so an important part of recovery for an SI joint injury involves strengthening these muscles to make sure they’re working optimally.
The exact shape of the SI joint can vary pretty widely from one individual to another, and there are also pretty significant differences in joint structure that depend on factors such as gender and age.
Because of this, what works for one person may not work for another. I have found that the SI joint is like a puzzle, and you must approach it intellectually in order to figure it out.
Here are some posts I wrote to give you an introduction to the SI joint:
- Main functions of the SI joint
- Ligaments of the SI joint
- Where is the SI joint? Useful illustrations
- SI Joint Concepts: Useful terminology
- The SI joint acts like a shock absorber
- Finally, my own visual aides! (Some basic views of the SI joint).
- Major structures of the pelvis
- The SI joint is like a puzzle
Additionally, here’s a great video from Chad Madden of Madden PT that explains more about the anatomy of the SI joint:
I also highly recommend this video from Vicki Sims on some of the symptoms of SI joint dysfunction:
Feel free to let me know if you have any questions!
Photo Credits: Both of the illustrations above courtesy of Wikipedia.