The Joint Ventures' Blog

What is The Sacroiliac Joint (SIJ)?

Tuesday, May 07, 2019

The sacroiliac (SI) joint is one of the more controversial and debated joints in the PT world. Topics of debate include:

1) How stable is the SI joint?

2) Can the SI joint move out of place without a history of trauma?

3) How do we measure movement in the SI joint?

4) What tests do we use to evaluate the SI joint?

5) Can the SI joint be asymmetrical and not cause pain?

6) How do we treat SI joint pain?

With all of this and more, there is variety in how Physical Therapists view, examine, and treat it. It's beyond the scope of this blog to answer all of the questions above, but let's get some basics.

What exactly is the SI joint? The SI joint is the joint where the sacrum (tailbone) connects with the iliac bones of the pelvis. It is a weight bearing joint linking your torso to your lower body that helps to provide support and stability to the low back/pelvic area. There are individual left and right SI joints that are connected functionally through the pubic bones in the front of the pelvis. The SI joint is subjected to stress and strain, as other joints in the spine are, and therefore can be a source of pain. It is generally considered to be a stable joint because it is designed to tolerate intermittent compression and slight joint movements.


What does SI joint pain feel like? When it comes to assessing pain in the low back and pelvic region, it can be challenging to determine the exact cause. Symptoms related to SI joint pain can be similar to symptoms from other joints in the area, including the low back and hip. Careful examination will help with differential diagnosis. With that, there are some common patterns of symptoms that tend to be consistent with SI joint pain.

1) Pain is usually described as an ache;

2) Pain tends to be on one side of the lower back/pelvis/buttock and sometimes the groin;

3) It can typically be in a small area, but also can radiate into the buttock and upper thigh;

4) It rarely radiates below the knee;

5) There is generally no numbness or tingling;

6) Activities that may be painful are weight bearing activities such as standing, single leg standing on the affected side leg, walking, stair climbing, and sit to and from stand movements;

7) Symptoms usually improve with rest.

What causes an SI Joint issue? If you have a pelvic rotation, asymmetry, or slight leg length difference, it does not necessarily mean you have an SI joint issue. These varying alignment issues are often asymptomatic and are common without being problematic. However, there are some scenarios where there may be a potential for excessive mobility which can cause abnormal anatomic relationships within the joint. These scenarios include a history of trauma, conditions that cause ligament laxity, and/or prolonged corticosteroid use.


How do I know if I have an SI Joint issue? Careful history taking and examination by a healthcare provider are important in evaluating, diagnosing, and treating pain in this area. There is no gold standard for diagnosing specific SI joint pain. There are several commonly used clinical tests that attempt to diagnose pain by stressing the joint to reproduce symptoms. Also, bony landmark palpation and postural/alignment assessment are beneficial to determine if there are any structural abnormalities that are contributing to the pain. A thorough physical therapy evaluation can help to sort through the challenge of diagnosing pain in this area and help to establish a plan of care to help you feel better.

If you are experiencing any of the symptoms described in this blog post, you may want to consider scheduling an evaluation for physical therapy. If you are looking to learn more about the SI joint, please feel free to contact Dave Carleton at or stop by the Downtown Office

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