The sacroiliac joint (SIJ) is a term used to describe the place where the sacrum and the iliac bones join.
- The sacrum is located at the base of your spine. It is made up of 5 vertebrae, or backbones, that are fused together.
- The iliac bones are the two large bones that make up your pelvis. The sacrum sits in the middle of the iliac bones.
More About Your Problem
The main purpose of the joint is to connect the spine and the pelvis. As a result, there is very little movement at the SIJ.
Major reasons for pain around the SIJ include:
- Muscle tightness
- Pregnancy: the pelvis widens to prepare for birth, stretching the ligaments. These are strong, flexible tissue that connects bone to bone
- Different types of arthritis
- Difference in leg lengths
- Wearing away of the cartilage (cushion) between the bones
- Trauma from impact, such as landing hard on buttocks
- History of pelvic fractures or injuries
Although, SIJ pain can be caused by trauma, this type of injury more often develops over a long period.
What to Expect
Symptoms of SIJ dysfunction include:
- Pain in the lower back, usually only on one side
- Hip pain
- Discomfort with bending over or standing after sitting for long periods
- Improvement in pain when lying down
Your doctor may move your legs and hips around in different positions to help diagnose a SIJ dysfunction. You may also need to have x-rays or a CT scan.
Follow these steps for the first few days or weeks after your injury or when starting treatment for SIJ pain:
- Rest. Keep activity to a minimum and stop movements or activity that worsen the pain.
- Ice your lower back or upper buttocks for about 20 minutes 2 to 3 times a day. DO NOT apply ice directly to the skin.
- Use a heating pad to help loosen tight muscles and relieve soreness.
- Massage the muscles in the lower back, buttocks, and thigh.
- Take pain medicines.
For pain, you can use ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn), or acetaminophen (Tylenol). You can buy these medicines at the store without a prescription.
- Talk with your health care provider before using these medicines if you have heart disease, high blood pressure, kidney disease, or have had stomach ulcers or internal bleeding in the past.
- DO NOT take more than the amount recommended on the bottle or by your provider.
If this is a chronic problem, your doctor may prescribe an injection to help with pain and inflammation. The injection can be repeated over time if needed.
Keep activity to a minimum. The more time the injury has to rest, the better. For support during activity, you can use a sacroiliac belt or lumbar brace.
Physical therapy is an important part of the healing process. It will help relieve pain and increase strength. Talk to your doctor or physical therapist for exercises to practice.
Here is an example of an exercise for your lower back:
- Lie flat on your back with your knees bent and feet flat on the ground.
- Slowly, begin to rotate your knees to the right side of your body. Stop when you feel pain or discomfort.
- Slowly rotate back toward the left side of your body until you feel pain.
- Rest in the starting position.
- Repeat 10 times.
The best way to get rid of SIJ pain is to stick to a care plan. The more you rest, ice, and practice exercises, the quicker your symptoms will improve or your injury will heal.
Your doctor may need to follow up if the pain is not going away as expected. You may need:
- X-ray and imaging tests
- Blood tests to help diagnose the cause
When to Call the Doctor
Call the doctor if you have any of the following:
- Sudden numbness or tingling in your lower back and hips
- Weakness or numbness in your legs
- Sudden increase in pain or discomfort
- Slower than expected healing
SIJ pain - aftercare; SIJ dysfunction - aftercare; SIJ strain - aftercare; SIJ subluxation -aftercare; SIJ syndrome - aftercare
Cohen SP, Chen Y, Neufeld NJ. Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment. Expert Rev Neurother. 2013;13:99-116.
Isaac Z, Feeney R. Sacroiliac joint dysfunction. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation. 3rd ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 51.
Review Date 11/26/2014
Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.