The sacroiliac joints (SIJ) is a common source of lower back pain. The SIJ or tail bone is wedged between your left and right ilium.
The function of the joint is to transfer weight from your upper body down to your leg. For example, when you walk the weight will shift to the leg that’s in contact with the ground. When it does your body weight will pass through your lower back, SIJ, hip and down to your foot.
The area is commonly injured through active movement such as lifting, twisting or running and is often localised to either the left or right side with almost pin point location of pain.
The joint is covered with very strong ligaments and muscles and can be very painful to strain and cause difficulty weight bearing on that side.
These injuries are usually termed ‘functional’ injuries as there often is a problem in the quality of your movement and this area become over strained. Commonly muscles such as glute medius/minimus, obliques, transverse abdominus and pelvic floor can weaken and lead to pain at the SIJ. Females during pregnancy or after birth tend to be more susceptible as the ligaments become more flexible and the joint becomes less stable.
Manual treatment in conjunction with specific rehabilitation exercises will help ensure long term improvement.