SI Joint Pain (Sacroiliac Dysfunction): Symptoms, Causes & PT Treatment
Updated October 20261 minute read
The sacroiliac (SI) joints connect your spine to your pelvis. When one becomes irritated, you feel pain low and to one side — often near the dimple above the buttock — that can flare with standing, climbing stairs, or rolling in bed. It's common during and after pregnancy and very treatable with physical therapy focused on pelvic control and strength.
What is SI joint dysfunction?
The SI joints transfer load between your upper body and legs. "Dysfunction" means one joint is moving or loading in a way that irritates it, producing localized pain.
Symptoms
Pain is usually low, to one side, below the belt line, sometimes spreading into the buttock or groin. It often flares with single-leg activities (stairs, getting out of a car), standing a long time, or rolling over in bed.
What causes it / risk factors
Pregnancy and postpartum changes, a fall onto the buttock, leg-length differences, and load imbalances contribute. It can also accompany other back problems.
How it's diagnosed
A clinician uses a cluster of provocation tests plus your history. Imaging is usually not needed for typical cases.
Physical therapy treatment
What a PT does. Your therapist calms the joint, improves pelvic and hip control, and strengthens the muscles that stabilize the pelvis. Exercises & progression (overview). Glute and core strengthening, load-management strategies, and sometimes a supportive belt short-term. Recovery timeline. Many cases improve within a few weeks to a couple of months.
Treatment options compared
PT is first-line. A SI belt or injections may help select cases. Surgical fusion is reserved for rare, severe, well-confirmed cases.
Red flags
Seek care for leg weakness, groin numbness, loss of bladder/bowel control, fever, or unexplained weight loss.
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Frequently asked questions
Typically low and to one side, near the dimple above the buttock, sometimes into the buttock or groin.
Sources (6)
- Vleeming A, Albert HB, Ostgaard HC, Sturesson B, Stuge B. European guidelines for the diagnosis and treatment of pelvic girdle pain. Eur Spine J. 2008. — PubMed
- Sacroiliac Joint Pain. StatPearls, NCBI Bookshelf. — NIH/NCBI Bookshelf (StatPearls)
- Jangra P, et al. A systematic review and meta-analysis of randomized controlled trials on the effect of various therapeutic interventions on sacroiliac joint dysfunction. J Bodyw Mov Ther. 2025. — J Bodyw Mov Ther
- Laslett M, et al. Evidence-based diagnosis and treatment of the painful sacroiliac joint. J Man Manip Ther. 2008. — J Man Manip Ther
- Hayden JA, et al. Exercise therapy for chronic low back pain. Cochrane Database Syst Rev. 2021. — Cochrane
- MedlinePlus: Back Pain. — MedlinePlus
This article is for education only and isn't medical advice. Always talk to a licensed clinician about your specific situation.