What Is Sacroiliac Joint Dysfunction?

Have you ever had that nagging lower back or deep buttock pain that just doesn’t quite make sense? You can’t recall any injury or lifting something heavy, and stretching or resting doesn’t seem to fully resolve it. Maybe you’ve even been told it’s “just sciatica” or general low back pain, but the usual advice isn’t helping.

This is a common frustration. One often-overlooked contributor may be the sacroiliac (SI) joint. SI joint dysfunction is frequently misidentified, yet accurate diagnosis plays an important role in guiding appropriate care and improving long-term outcomes.

What we’ll cover

• What the sacroiliac joint is
• Common causes of SI joint dysfunction
• How SI joint pain differs from sciatica
• How SI joint dysfunction is assessed
• How chiropractic care may support management

What is the sacroiliac joint?

The sacroiliac joints are located where the sacrum (the triangular bone at the base of your spine) meets the ilium (the large bones of the pelvis). You have two SI joints—one on each side.

Their primary role is to transfer load between your upper body and your legs, acting as a bridge that absorbs shock and provides stability during movement.

Unlike more mobile joints such as the shoulder or knee, the SI joints have very limited movement. However, this small degree of motion is important. When the joint moves too much (hypermobility), too little (hypomobility), or asymmetrically, it may contribute to pain and dysfunction. Due to its deep location and subtle movement, SI joint issues are often overlooked or misdiagnosed.

Common causes of SI joint dysfunction

SI joint dysfunction can arise from a range of factors, often related to how load is transferred through the pelvis.

Common contributors include:

• Trauma (e.g. falls onto the buttocks, motor vehicle accidents, sporting injuries)
• Pregnancy and the postpartum period (due to hormonal changes and altered biomechanics)
• Leg length differences, which may create uneven pelvic loading
• Underlying hip or lumbar spine conditions
• Repetitive one-sided activities (e.g. carrying a child on one hip)
• Prolonged sitting or standing, particularly with poor posture

These factors can alter how forces move through the pelvis over time, potentially contributing to irritation of the SI joint.

How is SI joint pain different from sciatica?

This is an important distinction.

SI joint pain typically presents as:

• Pain in the lower back and buttock
• Sometimes extending into the groin or back of the thigh
• Rarely travelling below the knee

Sciatica, on the other hand, follows the path of the sciatic nerve and often includes:

• Pain radiating down the leg, sometimes to the foot
• Tingling, numbness or weakness

While these patterns can help guide understanding, SI joint dysfunction and sciatica can coexist. A thorough assessment is important to help differentiate between the two and guide appropriate care.

How is SI joint dysfunction assessed?

Assessment typically involves a combination of clinical reasoning and physical examination.

This may include:

• A detailed patient history (onset, behaviour, and pattern of symptoms)
• Orthopaedic and movement testing
• SI joint provocation tests such as:
  • FABER’s test
  • Gaenslen’s test
  • Thigh thrust test

No single test is definitive. However, a cluster of positive findings can improve diagnostic accuracy.

In some cases, imaging such as X-ray, CT or MRI may be used to rule out other conditions, although SI joint dysfunction itself may not always be clearly visible on imaging.

How can chiropractic care help?

Chiropractic care may be helpful in managing SI joint dysfunction, particularly when there is a biomechanical component.

Care may involve:

• Gentle joint adjustments or mobilisations to support more balanced movement
• Soft tissue techniques targeting surrounding muscles (e.g. gluteals, piriformis, hip flexors)
• Postural and ergonomic advice to reduce ongoing strain
• Individualised exercises to support pelvic stability and core control

Management is typically tailored to the individual, with a focus on addressing contributing factors and supporting longer-term function.

Sacroiliac joint dysfunction is a common yet often overlooked source of lower back and buttock pain. Because symptoms can overlap with conditions like sciatica, it may be misidentified, which can delay appropriate care.

If you’ve been experiencing persistent pain that doesn’t quite fit typical patterns, the SI joint may be worth considering as part of a broader assessment.

Seeking a professional opinion can help guide diagnosis and next steps, rather than assuming it is “just a bad back” or “just sciatica.”

References

Cohen, S. P. (2005). Sacroiliac joint pain: A comprehensive review of epidemiology, diagnosis and treatment. Anesthesia & Analgesia, 101(5), 1440–1453.

Laslett, M. (2008). Evidence-based diagnosis and treatment of the painful sacroiliac joint. Journal of Manual & Manipulative Therapy, 16(3), 142–152.

Vleeming, A., Schuenke, M. D., Danneels, L., & Willard, F. H. (2012). The functional coupling of the deep abdominal and paraspinal muscles: The effects of simulated paraspinal muscle contraction on force closure of the sacroiliac joints. Spine, 37(20), E1249–E1257.

Szadek, K. M., van der Wurff, P., van Tulder, M. W., Zuurmond, W. W., & Perez, R. S. (2009). Diagnostic validity of criteria for sacroiliac joint pain: A systematic review. Journal of Pain, 10(4), 354–368.