Sacroiliac (SI) joint pain radiates deep into the buttock and lower back. The symptoms typically include a dull ache localized to one side that worsens with activity and prolonged positions. The pain may also extend down the leg similar to sciatica.
In This Article:
Hallmark Symptoms and Signs of SI Joint Dysfunction
Common symptoms of SI joint dysfunction include some combination of:
- Lower back pain that feels dull, aching, and can range from mild to severe. Lower back pain is typically felt only on one side, but in some cases may be felt on both sides.
- Pain that spreads to the hips, buttocks, and/or groin. One of the most common areas to feel SI joint pain is in the buttocks and upper back or side of the thigh. Pain is typically felt only on one side, but may be felt on both sides.
- Sciatic-like pain in the buttocks and/or backs of the thighs that feels hot, sharp, and stabbing and may include numbness and tingling. Sacroiliac joint dysfunction may cause sciatica-like symptoms that rarely extend below the knee.
- Stiffness and reduced range-of-motion in the lower back, hips, pelvis, and groin, which may cause difficulty with movements such as walking up stairs or bending at the waist.
- Worsened pain when putting added pressure on the sacroiliac joint, such as climbing stairs, running or jogging, and lying or putting weight on one side.
- Instability in the pelvis and/or lower back, which may cause the pelvis to feel like it will buckle or give way when standing, walking, or moving from standing to sitting.
Aggravation of the sacroiliac joint can commonly result in inflammation, also called sacroiliitis. This condition may be the primary cause of pain, stiffness, and other symptoms.
Causes and Risk Factors for Sacroiliac Joint Dysfunction
Certain factors can raise the risk of developing sacroiliac dysfunction and pain, including:
- Gait issues, such as leg length discrepancy or scoliosis, which can place uneven pressure on one side of the pelvis, causing wear-and-tear on the SI joint and an increased risk of pain.
- Pregnancy or recent childbirth can commonly cause sacroiliac joint pain in women due to weight gain, hormonal changes causing ligaments in the SI joint to relax (hypermobility), and pelvic changes associated with childbirth. For some women, ligaments may remain loose after childbirth and cause sacroiliac joint pain and instability to continue.
- Prior lower back surgery, which can displace pressure to the sacroiliac joint. One study found that sacroiliac joint pain tends to be more common following a fusion surgery than a discectomy. 1 Guan F, Sun Y, Zhu L, et al. Risk Factors of Postoperative Sacroiliac Joint Pain for Posterior Lumbar Surgery: ≥2-Year Follow-up Retrospective Study. World Neurosurg. 2017 The same study found that multi-level surgery was more likely to cause sacroiliac joint pain than a single-level procedure. Sacroiliac joint pain has also been reported following hip joint replacement surgery and bone grafts taken from the iliac bone (the “wings” of the pelvis).
- Activities that place repeated stress on the joint, such as contact sports, regular heavy lifting, or labor-intensive jobs. If pelvic and/or low back muscles are unconditioned, stress from prolonged sitting or standing may also contribute to SI joint pain.
In many cases, sacroiliac joint pain may arise gradually with no obvious cause. Other cases may be the direct result of injury or trauma, such as the jolt from a fall.
- 1 Guan F, Sun Y, Zhu L, et al. Risk Factors of Postoperative Sacroiliac Joint Pain for Posterior Lumbar Surgery: ≥2-Year Follow-up Retrospective Study. World Neurosurg. 2017