About sacroiliac joint pain
The sacroiliac, or SI, joints sit on either side of the sacrum, the flat bone at the base of the spine. They move only slightly, but they transfer a great deal of force between the upper body and the legs with every step.
When an SI joint becomes irritated, pain usually centers just below the belt line on one side and can spread into the buttock, groin, or back of the thigh. Because it can mimic a disc problem or hip problem, a careful exam matters.
Common symptoms
- Pain on one side of the low back, just below the waist
- Buttock pain that may spread into the back of the thigh or groin
- Pain with climbing stairs, standing on one leg, or getting in and out of a car
- Pain when rolling over in bed or after sitting for a long time
- Tenderness over the bony bump at the back of the pelvis
Common causes and risk factors
- Falls onto the buttock or other direct injuries
- Pregnancy and childbirth, which loosen and load the joint
- Uneven gait, a leg length difference, or single-leg sports such as running
- Inflammatory arthritis, such as ankylosing spondylitis
- Prior lumbar fusion, which can shift more stress onto the SI joint
How we diagnose it
Dr. Chen uses a series of hands-on provocation tests that stress the SI joint from different directions, along with a hip and spine exam to rule out other sources. Imaging helps exclude other problems and can show inflammatory arthritis. When the source is still uncertain, a diagnostic SI joint injection with numbing medicine under image guidance helps confirm whether the joint is driving your pain.
How Propel treats sacroiliac joint pain
Conservative care comes first, with progressive strengthening of the hips, glutes, and trunk that improves how force moves through the pelvis. We also review running form, training load, and sleep so that you can keep exercising while symptoms settle.
When pain persists, Dr. Chen may perform an image-guided sacroiliac joint injection to calm inflammation and confirm the diagnosis. For pain that keeps returning after a helpful injection, joint denervation targets the small nerves that carry pain from the SI joint and can offer longer relief.
What to expect at your visit
- 1.
We listen first
Your visit opens with a real conversation: how the problem started, what you have already tried, and the activity you want back.
- 2.
Exam and in-office ultrasound
A hands-on exam, then ultrasound at the exam table, often while you move, so your physician can see the tendon, joint, or nerve involved.
- 3.
A clear diagnosis and plan
You leave knowing what is wrong and what your options are, from strength-based rehab to procedures, and why we recommend each one.
- 4.
Treatment and follow-through
Most procedures happen here in the office. We coordinate with your physical therapist and check progress against the goals you set.
Questions about sacroiliac joint pain
- How can you tell SI joint pain from a disc problem?
- SI joint pain usually sits below the belt line on one side and rarely causes numbness or pain below the knee. A pinched nerve from a disc more often causes pain, tingling, or weakness that runs into the lower leg or foot. The exam and, if needed, a diagnostic injection help sort out the difference.
- Is a sacroiliac belt helpful?
- A pelvic support belt can ease pain for some people during a flare or during pregnancy. It is best used as a short-term aid while strength work builds lasting support around the joint.
- What is SI joint denervation?
- SI joint denervation uses controlled heat to quiet the small nerves that carry pain signals from the back of the joint. It is usually considered after a diagnostic injection or nerve block has clearly reduced pain. Relief can last many months, and the nerves slowly recover over time.