Sacroiliac (SI) Joint Pain: Symptoms and Solutions

Lower back pain is one of the most common reasons people seek medical care. But not all lower back pain comes from the spine itself. In many cases, the true source may be the sacroiliac (SI) joint.

Understanding SI joint pain, its symptoms, causes, and treatment options, can help you find relief faster and avoid prolonged discomfort.

What Is the Sacroiliac (SI) Joint?

The sacroiliac joints connect the sacrum (the triangular bone at the base of your spine) to the iliac bones of the pelvis. You have two SI joints—one on each side of your lower back.

These joints:

• Help transfer weight from your upper body to your legs
• Provide stability while standing and walking
• Absorb shock during movement

Although the SI joints move only slightly, even small dysfunctions can cause significant pain.

Common Symptoms of SI Joint Pain

SI joint pain is often mistaken for a lumbar spine issue, sciatica, or hip problems. Recognizing the pattern of symptoms can help identify the source.

1. Lower Back Pain (Usually One-Sided)

Pain is typically felt on one side of the lower back, just below the waistline. Some patients describe it as a deep, aching sensation.

2. Buttock or Hip Pain

Pain may radiate into the buttock or outer hip area. It can sometimes mimic sciatica.

3. Pain That Worsens With:

• Prolonged standing
• Climbing stairs
• Getting in and out of a car
• Rolling over in bed
• Sitting for long periods

4. Feeling of Instability

Some people report a sense that their pelvis feels unstable or “out of alignment.”

What Causes SI Joint Pain?

• Trauma or injury (such as a fall or car accident)
• Pregnancy (due to hormonal changes and ligament laxity)
• Leg length discrepancy
• Arthritis or degenerative joint disease
• Prior lumbar spine surgery
• Repetitive stress from sports or physical labor

Inflammation, joint stiffness, or abnormal movement patterns can all trigger symptoms.

How SI Joint Pain Is Diagnosed

• A detailed medical history
• Physical examination with specific stress tests
• Imaging studies (X-ray, MRI, or CT scan)
• Diagnostic SI joint injection to confirm the source of pain

Accurate diagnosis is essential to ensure appropriate treatment.

Treatment Options for SI Joint Pain

1. Physical Therapy

Targeted exercises strengthen the core and pelvic muscles, improve stability, and reduce strain on the joint.

2. Anti-Inflammatory Medications

NSAIDs may reduce inflammation and pain during flare-ups.

3. SI Joint Injections

Image-guided corticosteroid injections can decrease inflammation and provide both diagnostic confirmation and therapeutic relief.

4. Radiofrequency Ablation (RFA)

For chronic SI joint pain, RFA can interrupt pain signals from the affected nerves.

5. Minimally Invasive SI Joint Fusion

In rare cases where conservative treatments fail, minimally invasive stabilization procedures may be considered.

When to See a Specialist

• Lower back pain persists longer than a few weeks
• Pain interferes with daily activities
• Over-the-counter treatments are not helping
• Symptoms keep returning

Final Thoughts

SI joint pain is a common but often overlooked cause of lower back discomfort. The good news is that effective treatments are available. With the right diagnosis and personalized care plan, many patients experience significant improvement without surgery.

If you suspect your lower back pain may be coming from the SI joint, a thorough evaluation can help determine the best next steps toward relief.