Sacroiliac Joint Pain
The sacroiliac (SI) joint connects your sacrum (the triangular bone at the base of your spine) to your ilium (pelvis). It’s a commonly overlooked cause of one-sided low back and buttock pain, and is frequently misdiagnosed as a lumbar or hip problem. Getting an accurate diagnosis is the key to effective treatment.
Who Gets It?
SI joint pain can affect anyone, but is particularly common in:
- Pregnant and postpartum women (hormonal laxity affects joint stability)
- People with leg length differences or altered gait
- Athletes involved in running, cycling or asymmetrical sports
- People following a fall directly onto the buttock
- Those who have had lumbar spinal fusion (increased load on adjacent joints)
Symptoms
- One-sided pain in the lower back, buttock or top of the hip
- Pain that can refer down the back of the thigh (but rarely below the knee)
- Discomfort with prolonged sitting, standing or walking
- Pain rolling over in bed or climbing stairs
- Aching after activity that settles with rest
- Tenderness directly over the SI joint on the affected side
Assessment
Diagnosing SI joint pain requires a cluster of specific clinical tests — no single test is definitive. We use a structured provocation testing approach combined with movement assessment and a thorough history to reach a confident diagnosis.
Treatment
Manual Therapy
- Joint mobilisation and manipulation of the SI joint and surrounding structures
- Soft tissue release of the gluteal, piriformis and lumbar muscles
Exercise Rehabilitation
- Pelvic stability and gluteal strengthening
- Hip and lumbar mobility work
- Motor control retraining to reduce abnormal loading
Other Approaches
- Dry needling to reduce muscular guarding
- SI belt or support during flare-ups (particularly in pregnancy)
- Biomechanical correction for contributing factors (gait, leg length, footwear)
Pregnancy-Related SI Joint Pain
SI joint pain is extremely common during and after pregnancy. Our women’s health physiotherapists are experienced in managing this sensitively, including when breastfeeding or in the early postpartum period.
