Sacroiliac Joint Pain

What Is the Sacroiliac Joint?

The sacroiliac (SI) joints connect the sacrum (base of spine) to the iliac bones of the pelvis. There are two SI joints, one on each side. These joints have limited movement but play an important role in transferring weight and forces between the upper body and legs. SI joint dysfunction is estimated to cause 15-30% of lower back pain cases.¹

Causes²

Too much movement (hypermobility)
Too little movement (hypomobility)
Pregnancy and childbirth
Leg length discrepancy
Arthritis
Trauma or injury
Spine surgery (especially fusion)
Infection (rare)

Symptoms

Pain in lower back on one side
Pain in buttock or hip
Pain may radiate to groin or thigh
Usually doesn't go below the knee
Worse with sitting, standing from sitting
Pain climbing stairs
Difficulty lying on affected side

Diagnosis³

Physical examination
Provocative tests (FABER, Gaenslen's, thigh thrust)
Multiple positive tests increase likelihood
Diagnostic injection (most definitive)
Imaging may rule out other conditions

Treatment

Conservative

Physical therapy
SI joint stabilization exercises
SI joint belt
NSAIDs
Ice or heat
Activity modification

Injections

Corticosteroid injections
May provide temporary relief
Can be repeated if helpful

Procedures

Radiofrequency ablation
Prolotherapy
SI joint fusion (severe cases)

Physical Therapy Exercises

Core stabilization
Gluteal strengthening
Gentle stretching
Pelvic floor exercises
Movement retraining

Self-Care

Avoid prolonged sitting
Change positions frequently
Use supportive seating
Sleep with pillow between knees
Avoid asymmetric activities

References

Cohen SP, Chen Y, Neufeld NJ. Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment. Expert Rev Neurother. 2013;13(1):99-116.
Vleeming A, Schuenke MD, Masi AT, et al. The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. J Anat. 2012;221(6):537-567.
Laslett M. Evidence-based diagnosis and treatment of the painful sacroiliac joint. J Man Manip Ther. 2008;16(3):142-152.