The sacroiliac (SI) joint is located at the lower portion of the spine, between the iliac bones and sacrum. This joint provides support and stability to the spine and plays a role in impact absorption when walking or lifting. Strong ligaments surround the SI joint to provide support, limit its movement, and assists with pressure absorption. SI joint pain may result from damage or injury to the joint and may cause painful sensations in the lower back and buttocks. Pain in the SI joint can produce pelvic pain and stiffness while mimicking other sources of lower back pain, such as hip problems or a herniated disc.
Other names for SI joint pain include SI joint dysfunction, SI joint syndrome, and SI joint inflammation. You may experience acute or chronic pain in your SI joint that may be constant or intermittent.
You can somewhat prevent and protect yourself from developing some types of SI joint dysfunction by:
Using ergonomic chairs and desks
Practicing proper posture when sitting, standing, moving, and sleeping
Using proper lifting techniques
Maintaining a healthy weight
Exercising or stretching regularly
Sitting less during the day
Sitting on well-cushioned surfaces, limiting the number of hard surfaces you sit on
Not smoking or consuming tobacco-based produces
Yoga, functional mobility training, and gentle stretching
Physical or chiropractic therapy
Medications: Over-the-counter pain relievers or topical creams, prescription pain relievers or muscle relaxants
Your healthcare provider may ask you to lose or gain weight if you are obese, overweight, or underweight in conjunction with other treatment options. If an underlying medical condition is the cause of your SI pain, your healthcare professional will add treatment options for that specific condition to your treatment plan.
Pain in lower back and buttock
Pain radiating to the lower hip, groin, or upper thigh
Affecting one side more than other
Pain worsening when sitting, standing, sleeping, walking, or climbing stairs
Pain worsening when shifting positions
Numbness, tingling, or weakness in the leg
Limited mobility in lower back and hips
Stiffness in lower back, hips, pelvis, and groin
Instability in pelvis or lower back
Your healthcare provider will ask about the following information:
The frequency, duration, and severity of your symptoms
Your lifestyle habits and exercise regimen
All medications you take, including over-the-counter medicine, supplements, vitamins, illicit drugs, or prescription medication
Your medical history, including other medical conditions
Any recent or past trauma to the SI joint
Familial history of similar symptoms
Your doctor will also conduct a physical exam, in which they will test the strength, mobility, and flexibility in your lower back, hips, and legs. They will inspect the SI joint and surrounding area for any physical deformities or bruising. They will apply pressure to various spots near the SI joint to test for tenderness or sensitivity.
There is no single diagnostic test to diagnose your SI dysfunction, but your healthcare provider will order testing to rule out other possible causes of your pain. They may order diagnostic tests, such as:
SI joint injection
Many causes of SI joint pain are idiopathic, meaning they have no known cause. Other causes of SI joint dysfunction include:
Too loose or tight of ligaments surrounding the joint
SI joint instability
Trauma to the SI joint
Pregnancy and childbirth for those with uteruses
Obesity or being underweight, as both increase the pressure on your SI joint
Hip or spine surgery
Activities that place repeated stress on SI joint, such as contact sports, labor-intensive jobs, or heavy lifting
Uneven pelvic movement
Legs are different lengths
Arthritis in hips or knees
Autoimmune disorders, such as axial spondyloarthritis
Wearing walking boot on foot or ankle
Wearing non-supportive footwear
SI joint pain causes about 15-30% of all lower back pain in the United States.
Approximately 80% of American adults will experience lower back pain of some kind during their lives.
Younger and middle-aged women more commonly experience some form of SI joint pain.
Those who are pregnant or recently gave birth may be at an increased risk for developing SI joint dysfunction.