The sacroiliac (SI) joint is an incredibly strong, weight transferal synovial plane joint characterized by irregular elevations and depressions that interlock with the sacrum on one side and the ilium bones on the other. It is meant to remain relatively stable and only move a small amount in order to transfer forces between the body and the legs, acting as a type of shock absorber. However, it can get tight and irritated and that is what causes pain.
There are several ways to help alleviate SI joint pain. Stretching the muscles surrounding the joint can loosen them up and relieve tension. It is also important to try and avoid sitting for long periods of time. That will help to prevent the muscles and ligaments around the joints from getting tight and causing increased stress.
If the pain is severe enough, a physical therapist can design a stretching and strengthening program for you. They can also teach you how to perform sacral resets, which are movements that can help re-align the joint and alleviate the pain.
If you are suffering from mild SI dysfunction, it can be alleviated with a few sacral resets and a yoga practice that includes poses for the core and hips that will help to strengthen them. It is best to practice these at least three times a day and to stay attuned to the symptoms so that you can stop if your symptoms intensify. It is recommended to visit a professional if your pain persists after trying these at home for a week.