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by Erin Looney, DPT


The sacroiliac joint (SIJ) is one of those tricky little joints that is too often overlooked in patients that suffer from low back and hip pain.  I see SIJ dysfunction regularly with my patients that complain of back or hip pain. Ok, so what is it?  Each person has a left and right SIJ.  It is the junction between the sacrum (triangle bone that forms the base of the spine) and the ilium (bone that is part of the pelvis and connects to the hip) on either side of the low back.  The picture above should make this more clear.  This is a tight joint that allows very little motion, but withstands a great deal of stress as the upperbody and trunk push down through the legs and pelvis.  This joint must be able to withstand the weight of the upper body and trunk as well as the twisting, bending, pulling and pushing demands of the upper and lower body. The SIJ is further stabilized by several ligaments and layers of muscles that are stacked on top of those ligaments.

SIJ pain generally stems from one of 3 scenarios:

1).  Hypomobility of the joint – This may or may not cause pain.  In this scenario the mobility of the joint is restricted.  This joint can be “stuck” and out of place.  Patients usually experience pain in and around the SIJ – this can include one side of the low back and the buttocks region.  These patients often experience pain when transitioning from one position to the next (ex. moving from sitting to standing) and when standing on the leg of the painful side.

2).  Hypermobility of the joint – This may or may not cause pain.  In this case the joint moves excessively and easily shifts in and out of place.  Women with a history of pregnancy often experience this due to the hormonal changes that lead to ligamentous laxity and the stress placed on the pelvis by the baby during pregnancy.  These patients generally experience pain after being in a sustained position, and feel better with a change of position (ex.  pain after standing 15 min, relief with walking).

3).  Normal mobility with pain – This is less common, but it is possible to have pain in the region of the SIJ without having hyper/hypomobility.  This generally occurs when there is a restriction in the hip or low back, or in the case of a muscle imbalance.

SYMPTOMS – If you have any of the following symptoms it may be worth it to evaluate the SIJ, low back, hip, sacrum and pelvis:

– Pain on one side of your low back, gluteal region

– Inability to bear weight on leg on affected side

– Pain with walking, stair climbing, turning in bed, getting in/out of the car

– Pain with prolonged positioning.

TREATMENT – There are many treatment options available for patients with SIJ pain.  They may include any of the following:

– Mobilization / Muscle Energy techniques – these are not your aggressive “cracking” technique.  They basically involve pressure and you activating certain muscles to help correct the position of the SIJ

– Stretching – This is focused on specific muscles that may be tight and contributing to the misalignment

– Strengthening – Again, this is focused on weak musculature that will help stabilize the SIJ.

– Soft tissue mobilization – This is geared toward loosening muscles that are in spasm.

If after reading this you think your back or hip pain might have another component to it, check with your doctor or physical therapist to see if your SIJ might be involved.  We see many patients with SIJ pain and are able to minimize and often eliminate much of their discomfort with specific manual and physical therapy treatment.

Dr. Looney is a Physical Therapist at Boston Sports Medicine