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The SI joint refers to the triangular shaped sacrum bone that connects the spine to the upper portion of the pelvis. SI means sacroilium.

There are two SI joints that sit on each side of your spine with ligaments that hold the bones together. The function of the SI joint is to bear the weight of your upper body when you sit or stand.

Common Causes of SI Pain

• SI ligaments are damaged
• Osteoarthritis
• Inflammation due to injury
• Falling down
• Repetitive pounding from sports such as jogging
• Muscle tightness in low back or backside
• Traumatic injury
• Prolonged sitting or standing
• Prolonged standing one one leg

SI Pain Symptoms

• Standing up may cause pain
• Pain may be located on one side of your lower back
• Pain may be worse in the morning than during the day
• Pain is most common in the low back and buttocks

Diagnosis and Treatment

If you think your pain may be caused by injury to the SI joint, make an appointment with your primary care doctor to get a preliminary diagnosis. Depending on their findings, your doctor may give you a treatment plan, or refer you to a spine specialist for further testing.

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