Learn about Sacroiliac Joint Dysfunction

A common cause of low back pain is an injury to the sacroiliac joint. In some cases, the exact reason why pain is experienced in the joint is unclear and when this occurs the condition is referred to as sacroiliac joint dysfunction. The guide below describes more about how this problem develops and the benefits of physiotherapy treatment. 

What part of the back is involved?

At the lower end of the spine, just below the lumbar spine lies the sacrum. The sacrum is a triangular shaped bone that is actually formed by the fusion of several vertebrae during development. The SI joint sits between the sacrum and the iliac bone (thus the name “sacroiliac” joint). On many patients you can identify these joints from the outside as two small dimples on each side of the lower back at the belt line.

The SI joint is one of the larger joints in the body. The surface of the joint is wavy and fits together similar to the way Lego® pieces fit together. Very little motion occurs in the SI joint compared to most other joints. The motion that does occur is a combination of sliding, tilting and rotation. The most that the joint moves in sliding is probably only a couple of millimeters, and may tilt and rotate two or three degrees.

Several large, very strong ligaments hold the SI joint together. The strongest ligaments are in the back of the joint outside of the pelvis. The pelvis is a ring shape so these ligaments work somewhat like the hoops that hold a barrel together. The joint shape and the ligaments are one component in keeping the joint stable; the other component is the force of the muscles. If the ligaments are torn, the pelvis can become unstable. This sometimes happens when a fracture of the pelvis occurs and the ligaments are also damaged. In most cases of injury to this joint, however, these ligaments are so strong that they are not completely torn unless a great amount of force is inolved, such as in motor vehicle accidents.

The SI joint does not move a large amount in adults, but during pregnancy this can change. During the end of pregnancy, as delivery nears, the hormones that are produced cause the SI joint to relax. This relaxation of the ligaments allows the pelvis to be more flexible so that birthing can occur more easily. Multiple pregnancies, which increase the amount of overall time that the joint is acting in a more flexible way, seem to increase the amount of arthritis that forms in the joint later in life. It should be highlighted again that in comparison to other joints in the body, such as the shoulders or hips, ‘excess’ movements in the SI joint are still relatively very small and are difficult or impossible for you to feel yourself. 

It appears that the primary function of the SI joint is to be a shock absorber, and to provide just enough motion and flexibility to lessen the stress on the pelvis, trunk, and spine. In addition, the motion at the SI joint functions in harmony with the biomechanical motion in the lower extremities during activities such as walking and running in order to transfer the impact load and to lessen the overall stress received by the body during these activities.

What does this condition feel like?

Most commonly the pain from an SI joint dysfunction is either directly over the SI joint itself or may radiate pain lower down into the buttocks. The pain may affect one side or both SI joints. Most times the pain from an irritable SI joint remains well above the knee, but in a few cases it can radiate down the leg all the way to the foot and may be confused with a herniated disc of the lumbar spine. The pain may also radiate into the groin area. People often feel muscle spasm or tightness in one or both of their buttocks muscles when the SI joint is affected.

Problems with the SI joint may make sitting difficult. Pain in one SI joint may cause a person to sit with that buttock tilted up as it is often uncomfortable to sit flat in a chair. Walking can also be very painful depending on the degree of irritability of the joint and whether or not the joint is considered to have too much movement or is deemed stiff. Increased motion at the joint, such as during pregnancy, can be a particularly debilitating problem which makes activities such as going up or down stairs, standing on one leg, putting on your shoes and socks, or getting in and out of a car difficult. Turning over in bed is also particularly difficult when the SI joint moves more than normal.

How do health care professionals diagnose the problem?

The history and physical examination are the most important tools that health care professionals, including your physiotherapist at Skill Builders, will use to diagnose a problem with your SI joint. Your therapist will want to know exactly where your pain is, if it radiates anywhere, when and how it started, and what activities ease or aggravate your symptoms. You will be asked about any injuries you may have sustained in the past such as falls or motor vehicle accidents. Women will be asked about pregnancies and whether or not they had pain during that time. You will also be asked about any other medical problems you might have such as rheumatic arthritis or related conditions.

Next your physiotherapist will physically examine your low back, sacral area, and lower extremities. First they will look at your natural posture in sitting and standing. They will also want to watch you walk and may ask you to go up and down stairs, squat down, hop, or stand on one leg. They will also check the movements of your low back and SI joint when you bend forward, backwards, sideways, or twist. In addition they will also want to look at the specific movements of your SI joint in standing as you stand on one leg while you bring your knee to your chest or put your leg back behind you. Your therapist will palpate (touch), around your painful area as well as many areas in your back, buttocks, and possibly your groin to determine which areas are causing most of the issue.

The next part of the physical assessment will include your therapist performing some special movement tests to confirm the diagnosis of SI joint pain and to rule out pain coming from other areas in your back, such as the lumbar discs. These tests may involve pushing on your SI joints, your back, your hips, or even your knees in order to put pressure through the SI area. Many of these tests can provoke pain directly over the SI joint and assist both in diagnosing the source of the pain, and also in assessing the motion of the SI joint.

Your physiotherapist will also want to check the range of movement and strength in the joints and muscles of your low back and your hips. As discussed above, a biomechanical dysfunction from too stiff or too mobile joints or muscles that are not strong enough or too strong can add stress to the SI joint and cause pain. As mentioned above, a leg length discrepancy can do the same, so this will also be measured.

Finally, your therapist will also assess your skin sensation, muscle strength, and reflexes in order to rule out your pain coming from areas other than the SI joint, such as a lumbar disc.

Treatment - Nonsurgical Rehabilitation

Physiotherapy at Skill Builders can be very useful for patients with SI joint pain. Your physiotherapist will assess your SI joint dysfunction and determine how much of your pain is coming directly from this joint. They will then determine how well the joint is moving. The joint can be moving well, or there can be too much movement (hypermobile) or not enough movement (hypomobile.) Your individual physiotherapy treatment will be determined according to these findings. 

Portions of this document copyright MMG, LLC.

Skill Builders provides services for physiotherapy in Barrie.