Overview

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

Treatment options 

• Rest
• 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
• Back or hip bracing 
• Sacroiliac joint injections
• Radiofrequency ablation 
• Nerve ablations or blocks
• SI joint fusion surgery

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.

Symptoms

• 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

Diagnostic tests

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
• X-ray
• MRI
• CT Scan

Causes

Many causes of SI joint pain are idiopathic, meaning they have no known cause. Other causes of SI joint dysfunction include:

• Ankylosing spondylitis
• Osteoarthritis 
• Gout 
• 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
  • Possible causes:
    • 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

Facts 

• 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.