SI-joint anatomy
The sacroiliac joints are located between the sacrum, or the triangular bone at the base of the spine, and the ilium, or the hip bone. Their functions include transferring forces between the upper and lower body and acting as shock absorbers. The SI joint is a synovial joint, meaning it has a joint capsule surrounding it and synovial fluid inside, which nourishes and lubricates the joint. Between the bones are cartilaginous structures. Additionally, the SI joints are surrounded by very strong ligaments, and bony structures also ensure that the SI joints are extremely supportive and structurally sound. Movement occurs only about 2-4 millimeters forward and backward. As a person ages, the structure of the SI joint further stiffens. Therefore, it is highly unlikely that your SI joint is out of place, even if someone has told you otherwise.
About SI-joint pain
Lower back pain is the world's leading cause of disability related to musculoskeletal disorders, but what is the role of the sacroiliac joints in relation to lower back pain and pelvic problems? Currently, it is believed that in approximately 3-30% of cases of lower back pain, there may be some factor related to the sacroiliac joint. There is a wide range of prevalence reported in various studies, so the topic should be critically examined. Accurately diagnosing sacroiliac joint problems is challenging based on current knowledge. (1,2,3) In this text, I categorize sacroiliac joint-related issues into three main categories:
Non-specific sacroiliac joint-related pain (pain originates from a structure within the sacroiliac joint, but the exact source of pain cannot be reliably determined)
Specific sacroiliac joint-related pain (e.g., fractures, spondyloarthropathy)
Pregnancy-related sacroiliac joint pain
Non-specific SI-joint pain
Non-specific pain means that in a specific area, such as in this case, in the sacroiliac joint area, there are structures known to cause pain, but we are unable to diagnose the exact/source of the pain accurately based on current knowledge. In fact, many musculoskeletal disorders are inherently non-specific. Imaging techniques (such as X-rays or MRI) may not necessarily confirm the origin of pain. This is partly because pain formation and experience are complex events influenced by factors beyond just biological structures. Although a precise diagnosis may not be achieved, most musculoskeletal conditions can still be effectively treated. Understanding non-specificity is important, as it often leads to frustration among patients if not adequately explained by professionals.
Non-specific sacroiliac joint pain typically manifests in the lower back, buttock, and/or hip area and may also radiate towards the posterior thigh. It can be challenging to pinpoint the exact location of the pain. Pain may be aggravated or relieved during movement, and sitting may exacerbate symptoms. Resting pain is also possible, and walking may be difficult for some. Patients may also receive a diagnosis called sacroiliac joint dysfunction. The underlying idea of sacroiliac joint dysfunction is that if the joint's movement is disrupted (either too much or too little movement), pain occurs. Typically, pain can be provoked during clinical examinations (Laslett tests) in a clinic setting. However, a challenge arises because, as mentioned earlier, the movement of sacroiliac joints is very subtle. Therefore, even if the joint is examined by a highly skilled professional, it is unlikely that movement can be reliably observed. We can provoke the joint, and it informs us about the source of pain, but the tests do not tell us why they cause pain. Nonetheless, it is useful that we can fairly well determine whether the pain originates from the lower back structures or specifically from the sacroiliac joint. In summary, research does not support the idea that we could analyze anything other than whether the joint potentially causes pain through clinical tests.
Treatment for non-specific sacroiliac joint pain typically begins conservatively. Patients are directed to rehabilitative exercises, and manual therapy (e.g., massage) may also be used for pain relief. Nerve blocks may also provide pain relief. Sometimes further investigations may be necessary, if there is suspicion of an inflammatory issue, such as sacroiliitis. One of the most essential aspects of treatment and its success is the patient's own beliefs regarding the condition, and professionals should address these beliefs. If you suffer from sacroiliac joint pain, read the following:
Your sacroiliac joint is unlikely to be dislocated. This would require a high-energy event such as a car accident or other significant trauma.
Your sacroiliac joint is not 'locked,' even though it may feel that way. The SI joint is also structurally very strong, so its movement is minimal anyway. Even if your SI joint has been manipulated and produces a popping sound, it does not mean it has returned to its place. Pain relief comes through other pathways.
A diagnosis of SI joint dysfunction is scientifically poor and unreliable.
A 'weak' core is unlikely to be the cause of your SI joint problems. Core muscles are important, but no more so than any other muscles.
Even if your pelvic area is painful, it is often sensible to move within the limits of pain tolerance. Pain is not always synonymous with damage. This is especially true in chronic conditions.
Your body is resilient and adapts to various stimuli. Even long-standing problems are often possible to overcome.
Spesific SI-joint pain
Pain in the sacroiliac joint can also result from trauma, such as a fall or other accident. This can lead to various fractures and/or ligament and muscle injuries. Sacroiliac joint pain can also be divided into extra-articular pain caused by structures outside the joint and intra-articular problems caused by structures within the joint. Other conditions causing pain may include osteoarthritis and sacroiliitis, which refers to inflammation of the sacroiliac joint or joints. Sacroiliitis typically occurs in association with ankylosing spondylitis. In pregnant women, up to 50 percent may experience pain in the pelvic area and sacroiliac joint. However, we will write a separate article on this topic. (6)
Joonas Virtanen
Osteopath, sports massage therapist & strength coach
Ilari Keckman
Osteopath, sports massage therapist & educator
References
Comments