Sacroiliac Joint Dysfunction.
What is sacroiliac joint dysfunction?
The sacroiliac joints (SIJ) are the two joints connecting the sacrum — the triangular bone at the base of the spine — to the iliac bones of the pelvis. They are stabilised by some of the strongest ligaments in the body and under normal circumstances allow only a few degrees of movement — subtle nodding and rotating motions called nutation and counternutation — that play an important role in load transfer between the spine and lower limbs during walking, standing and lifting.
Sacroiliac joint dysfunction (SIJD) refers to a mechanical disruption of normal SIJ movement and load transfer — either excessive movement (hypermobility) or restricted movement (hypomobility) — that produces pain and functional impairment. It is distinct from sacroiliitis, which involves active inflammation of the joint from systemic inflammatory conditions such as ankylosing spondylitis. SIJD is a mechanical problem; sacroiliitis is primarily an inflammatory one, though both can coexist and their symptoms overlap significantly.
How common is SIJ dysfunction as a source of pain?
SIJ dysfunction is more common as a pain source than was historically appreciated. Research using controlled diagnostic SIJ injections suggests the sacroiliac joint is responsible for approximately 15 to 25% of chronic lower back pain in adults — making it one of the most significant but frequently missed pain generators in the lumbar and pelvic region. It is particularly common in pregnancy and the postnatal period, following falls onto the buttocks, and in people with leg length discrepancy.
What causes SIJ dysfunction?
Pain can be caused by a variety of factors, including injury, inflammation, and degenerative conditions. The underlying mechanism involves disruption of the normal force closure of the SIJ — the muscular compression of the joint that supplements the passive ligamentous stability. When the surrounding muscles — gluteals, deep hip rotators, thoracolumbar fascia, pelvic floor and multifidus — fail to adequately compress and stabilise the SIJ under load, abnormal joint mechanics produce pain and dysfunction.
Contributing factors include pregnancy and the postnatal period (where relaxin-mediated ligamentous laxity increases joint mobility beyond normal limits), trauma to the pelvis or sacrum, leg length discrepancy, asymmetric loading patterns from sport or work, previous lumbar spinal fusion (which transfers load to the SIJ), and inflammatory joint conditions that alter the joint's mechanical behaviour. In people with hypermobility, the generalised connective tissue laxity can produce SIJD as part of a broader pattern of pelvic and spinal instability.
What are the symptoms?
Symptoms include pain in the lower back, buttocks, and hips, as well as stiffness and reduced range of motion. The pain can be felt on one side or both sides of the body, and can be aggravated by activities such as standing, walking, or climbing stairs.
The pain is typically unilateral — though bilateral presentations occur — and is localised to the posterior pelvis below the level of L5, often described as deep buttock pain. It may refer into the groin, posterior thigh and occasionally the calf, patterns that overlap with disc-related sciatica and piriformis syndrome. Activities that load the SIJ asymmetrically — rolling over in bed, single-leg stance, climbing stairs, prolonged sitting or standing — are characteristic aggravating factors. The pain often improves with rest and is worse first thing in the morning, settling with movement.
How is it diagnosed?
No single clinical test definitively diagnoses SIJ dysfunction, but a cluster of positive provocation tests — the FABER test, posterior pelvic pain provocation test (P4 or thigh thrust test), Gaenslen's test, and sacral distraction and compression tests — combined with characteristic symptoms and the response to SIJ-specific manual therapy forms the basis of clinical diagnosis. Three or more positive provocation tests from this cluster provides good diagnostic accuracy.
Imaging — X-ray and MRI — helps exclude structural causes including fractures, tumours and inflammatory arthritis. A positive response to a diagnostic SIJ injection (temporary pain relief from anaesthetic injected directly into the joint) confirms the SIJ as the pain source when clinical diagnosis is uncertain.
How can physiotherapy help?
Physiotherapy is a valuable part of the treatment plan for SIJD, addressing pain, improving joint mechanics, and building the muscular support system that stabilises the joint.
The foundation of physiotherapy management for SIJD is the force closure model — rebuilding the muscular compression of the SIJ that supplements passive ligamentous stability. The primary targets are the deep stabilising muscles: transversus abdominis, multifidus, pelvic floor, and deep hip external rotators. These muscles — when functioning optimally — provide the active joint compression that reduces abnormal SIJ movement and pain during loading. Real time ultrasound guides retraining of these deep muscles, providing direct biofeedback on their activation quality.
Manual therapy including joint mobilisations and manipulations improves the alignment and function of the sacroiliac joint and can help reduce pain and restore proper joint movement. Sacroiliac belts — worn around the pelvis at the level of the greater trochanters — provide external compression that reduces SIJ movement and offers short-term pain relief, particularly during the acute phase and in pregnancy-related presentations.
Hip abductor and gluteal strengthening — particularly the gluteus medius and deep hip external rotators — provides the proximal compression force that stabilises the SIJ during single-leg loading activities. This is as important as the deep core retraining and is frequently undertreated in SIJ rehabilitation.
Dry needling of the gluteal and lumbar musculature assists with pain management. Leg length discrepancy contributing to SIJ overload may be addressed with heel raise orthotics. Postural and movement education — how to sit, stand, roll in bed and lift without excessively stressing the SIJ — is a practical and important component.
Clinical Pilates provides an excellent structured environment for progressive lumbopelvic and hip stabiliser strengthening, with the ability to precisely modify load and range for patients at different stages of rehabilitation.
For patients whose SIJD has not responded to appropriate conservative management and for whom sacroiliac joint fusion is being considered, physiotherapy prehabilitation and post-surgical rehabilitation are both important components of care.
Our physiotherapists Bethany Kippen and Emma Cameron and Exercise Physiologist Ash O'Regan all have experience in SIJ and pelvic conditions and are members of the Australian Physiotherapy Association. For patients with hypermobility-related SIJ instability, Yulia Khasyanova's specialist expertise is particularly relevant — see our joint hypermobility syndrome page for more on this population.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
The sacroiliac joints (SIJ) are the two joints connecting the sacrum — the triangular bone at the base of the spine — to the iliac bones of the pelvis. They are stabilised by some of the strongest ligaments in the body and under normal circumstances allow only a few degrees of movement — subtle nodding and rotating motions called nutation and counternutation — that play an important role in load transfer between the spine and lower limbs during walking, standing and lifting.
Sacroiliac joint dysfunction (SIJD) refers to a mechanical disruption of normal SIJ movement and load transfer — either excessive movement (hypermobility) or restricted movement (hypomobility) — that produces pain and functional impairment. It is distinct from sacroiliitis, which involves active inflammation of the joint from systemic inflammatory conditions such as ankylosing spondylitis. SIJD is a mechanical problem; sacroiliitis is primarily an inflammatory one, though both can coexist and their symptoms overlap significantly.
How common is SIJ dysfunction as a source of pain?
SIJ dysfunction is more common as a pain source than was historically appreciated. Research using controlled diagnostic SIJ injections suggests the sacroiliac joint is responsible for approximately 15 to 25% of chronic lower back pain in adults — making it one of the most significant but frequently missed pain generators in the lumbar and pelvic region. It is particularly common in pregnancy and the postnatal period, following falls onto the buttocks, and in people with leg length discrepancy.
What causes SIJ dysfunction?
Pain can be caused by a variety of factors, including injury, inflammation, and degenerative conditions. The underlying mechanism involves disruption of the normal force closure of the SIJ — the muscular compression of the joint that supplements the passive ligamentous stability. When the surrounding muscles — gluteals, deep hip rotators, thoracolumbar fascia, pelvic floor and multifidus — fail to adequately compress and stabilise the SIJ under load, abnormal joint mechanics produce pain and dysfunction.
Contributing factors include pregnancy and the postnatal period (where relaxin-mediated ligamentous laxity increases joint mobility beyond normal limits), trauma to the pelvis or sacrum, leg length discrepancy, asymmetric loading patterns from sport or work, previous lumbar spinal fusion (which transfers load to the SIJ), and inflammatory joint conditions that alter the joint's mechanical behaviour. In people with hypermobility, the generalised connective tissue laxity can produce SIJD as part of a broader pattern of pelvic and spinal instability.
What are the symptoms?
Symptoms include pain in the lower back, buttocks, and hips, as well as stiffness and reduced range of motion. The pain can be felt on one side or both sides of the body, and can be aggravated by activities such as standing, walking, or climbing stairs.
The pain is typically unilateral — though bilateral presentations occur — and is localised to the posterior pelvis below the level of L5, often described as deep buttock pain. It may refer into the groin, posterior thigh and occasionally the calf, patterns that overlap with disc-related sciatica and piriformis syndrome. Activities that load the SIJ asymmetrically — rolling over in bed, single-leg stance, climbing stairs, prolonged sitting or standing — are characteristic aggravating factors. The pain often improves with rest and is worse first thing in the morning, settling with movement.
How is it diagnosed?
No single clinical test definitively diagnoses SIJ dysfunction, but a cluster of positive provocation tests — the FABER test, posterior pelvic pain provocation test (P4 or thigh thrust test), Gaenslen's test, and sacral distraction and compression tests — combined with characteristic symptoms and the response to SIJ-specific manual therapy forms the basis of clinical diagnosis. Three or more positive provocation tests from this cluster provides good diagnostic accuracy.
Imaging — X-ray and MRI — helps exclude structural causes including fractures, tumours and inflammatory arthritis. A positive response to a diagnostic SIJ injection (temporary pain relief from anaesthetic injected directly into the joint) confirms the SIJ as the pain source when clinical diagnosis is uncertain.
How can physiotherapy help?
Physiotherapy is a valuable part of the treatment plan for SIJD, addressing pain, improving joint mechanics, and building the muscular support system that stabilises the joint.
The foundation of physiotherapy management for SIJD is the force closure model — rebuilding the muscular compression of the SIJ that supplements passive ligamentous stability. The primary targets are the deep stabilising muscles: transversus abdominis, multifidus, pelvic floor, and deep hip external rotators. These muscles — when functioning optimally — provide the active joint compression that reduces abnormal SIJ movement and pain during loading. Real time ultrasound guides retraining of these deep muscles, providing direct biofeedback on their activation quality.
Manual therapy including joint mobilisations and manipulations improves the alignment and function of the sacroiliac joint and can help reduce pain and restore proper joint movement. Sacroiliac belts — worn around the pelvis at the level of the greater trochanters — provide external compression that reduces SIJ movement and offers short-term pain relief, particularly during the acute phase and in pregnancy-related presentations.
Hip abductor and gluteal strengthening — particularly the gluteus medius and deep hip external rotators — provides the proximal compression force that stabilises the SIJ during single-leg loading activities. This is as important as the deep core retraining and is frequently undertreated in SIJ rehabilitation.
Dry needling of the gluteal and lumbar musculature assists with pain management. Leg length discrepancy contributing to SIJ overload may be addressed with heel raise orthotics. Postural and movement education — how to sit, stand, roll in bed and lift without excessively stressing the SIJ — is a practical and important component.
Clinical Pilates provides an excellent structured environment for progressive lumbopelvic and hip stabiliser strengthening, with the ability to precisely modify load and range for patients at different stages of rehabilitation.
For patients whose SIJD has not responded to appropriate conservative management and for whom sacroiliac joint fusion is being considered, physiotherapy prehabilitation and post-surgical rehabilitation are both important components of care.
Our physiotherapists Bethany Kippen and Emma Cameron and Exercise Physiologist Ash O'Regan all have experience in SIJ and pelvic conditions and are members of the Australian Physiotherapy Association. For patients with hypermobility-related SIJ instability, Yulia Khasyanova's specialist expertise is particularly relevant — see our joint hypermobility syndrome page for more on this population.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
