SI Dysfunction

Often when a person experiences low back pain the first thought that comes to mind is a pulled muscle or an injury to the spine.  However, this is not always the case. In some instance low back pain can stem from a dysfunction of a joint that most people have never heard of; the sacroiliac joint (SI).  Before a person can begin to understand what causes SI dysfunction a basic knowledge of the function and anatomy of the SI is required.

The SI joint is formed by the tailbone (sacrum) connecting to the left and right sides of the pelvis bones (Ilium).  The function of the SI joint is to act as a link to the lower spine and the pelvis. This allows the SI joint to function as a shock absorber for the pelvis and the lower back.  The SI joint also allows the hips to slightly rotate or twist while a person is walking or running.  This helps provide stability throughout the pelvis and disperse forces evenly through the pelvis and spine.

The most common cause of dysfunction of the SI joint is hyper-mobility or excessive movement.  The SI joint is an inherently rigid joint.  It is vital that the SI joint does not have too much uncontrolled motion or the SI joint will be placed in an abnormal position which will place additional stress onto the joint which results in pain.  In addition, if the SI joint becomes too flexible its ability to act as a shock absorber and transfer forces evenly throughout the pelvis and spine will be reduced, which also results in pain. SI hyper-mobility may occur after trauma such as a motor vehicle accident or falling and landing on ones buttock.

A person with a SI dysfunction will commonly complain of low back, buttock or hip pain. The pain may even transfer down the leg and mimic other conditions such as a bulged disc or sciatica.  Typically symptoms are worse when standing, walking or running and are relieved when lying down or resting. Bending over, climbing stairs and rising out of a seat can become difficult and painful too.  A person may notice that lying on their side for prolonged periods reproduces their pain as well.  There are many risk factors for developing an SI dysfunction.   Women are more likely to develop SI dysfunction than men.  Women who have given birth are also at greater risk.  People who are more flexible (i.e. gymnasts) are at greater risk of developing SI related pain as well.

In order to prevent excess motion from occurring, the muscles surrounding the SI joint must be well conditioned.  Specifically the transversus abdominis and oblique abdominals attach onto the surrounding area of the SI joint and aid in maintaining the position and stability of the SI joint.  Research has shown that contracting or firing the transversus abdominis significantly stiffens and stabilizes the SI joint. Furthermore, research has shown that the deep buttock muscles (gluteus medius and gluteus maximus) are important in maintaining the stability of the hips and pelvis.  If any of the muscles become too weak or lack proper endurance the likelihood of SI hyper-mobility increases.

Before a physical therapist can begin to treat a patient for SI Dysfunction a detailed evaluation has to be given.  For this condition X-rays and MRIs are not particularly useful in diagnosing SI dysfunction.  Instead, a history and a thorough physical examination has to be administered.  First the physical therapist will need to determine that the pathology is not originating from the back or the hip. The physical therapist will also observe for any strength deficits and if the patient is walking with any compensation patterns that could contribute to their pain.

Once the diagnosis of SI dysfunction has been reached the physical therapist will first focus on reducing any inflammation.  This may include ice or taping techniques which will unload pressure off of the SI joint.  In order to begin stabilizing the SI joint the physical therapist will then begin incorporating exercises that focus on strengthening the deep hip and core muscles.  As the patient’s ability to activate these muscles progresses exercises that focus on firing these muscles while the body is in motion will then be incorporated.  When the body is in motion (i.e. running) the SI joint is more likely to demonstrate excessive motion.  By performing more complex and dynamic strengthening exercises the deep core and hip muscles are forced to stabilize the SI joint.  This will result in restoring the patient’s ability to perform their favorite activities without discomfort.  The intensity and the difficulty of these exercises will vary depending on the patient’s overall goals and the severity of the patient’s symptoms.  Some people may just want to be able to bend over without discomfort while others may be planning on running a marathon or trying out for their favorite sport.

If a person seeks treatment then their prognosis for this condition is very good.  The majority of individuals with SI dysfunction respond well to conservative treatment.  Unfortunately, if a person ceases to perform their prescribed exercises their symptoms may reoccur.  Because of this it’s imperative that the patient continues to perform their home exercise program a few days each week, otherwise the patient may not be able to maintain their desired activity level.  Whether you are an avid runner or a couch potato a physical therapist can make SI instability become a thing of the past.

Don’t put up with low back pain; call Total Performance Physical Therapy for an examination today.


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