Pain in the lower back/legs is thought to be caused by a dysfunction in the sacroiliac, or SI, joint. Leg pain can be very difficult and could feel like sciatica or pain from a herniation of a lumbar disc.
Your sacroiliac joint is next to the bottom of the spine- just below your lumbar spine and above the coccyx, or tailbone. It connects your sacrum, which is the triangular bone at the bottom of the spine, with your pelvis. Typically, this joint has the following characteristics:
- Small and strong, being reinforced by the very strong ligaments around it.
- Doesn’t move very much.
- Transmits the forces of the upper body to the pelvis and legs.
- Acts as a shock-absorber for the body.
Though it’s not totally clear how this sacroiliac pain is caused, it is believed that a change in the normal motion of the joint could be the reason. The pain can be caused either by:
- Too much movement- this pain will be felt in the hips or lower back and could radiate into the groin.
- Too little movement- this pain will be felt on one side of the lower back or buttocks and tends to radiate down the leg. It usually stays above the knee, but in some cases, can extend to the foot or ankle. It is very similar to sciatica. Sacroiliac Pain is much more common in young and middle-aged women.
Diagnosing Sacroiliac Joint Pain
Coming to an accurate diagnosis of sacroiliac joint function can be hard because the symptoms actually appear to mimic other common conditions including mechanical back pain such as facet syndrome and other lumbar spine conditions such as radiculopathy and disc herniation.
Typically, your physician will make this diagnosis through a physical exam- by eliminating any other possible causes, and/or an injection to block the pain.
Physical Examination to Determine Source of Pain
Your physician may attempt to find out if your sacroiliac joint is the cause of your pain through movement of the joint, during a physical exam. If this movement causes you pain and no other cause can be pinpointed to explain your symptoms and pain, the sacroiliac joint is most likely the cause of your pain.
Some of the following could be used by your physician to determine if the sacroiliac joint is causing your pain:
Your physician will have you lie on the exam table face up, with the leg of the affected side hanging off the side towards the floor or resting on a nearby stool so that the sacroiliac joint is on the edge of the table.
Then, the opposite knee can be pulled to the chest in order to further isolate the sacroiliac joint on the side of the leg that is hanging. This position will over no support for your hip joint and pressing down on your pelvis or upper thigh could produce your pain.
Using Injections to Determine Source
An injection into the sacroiliac joint, called a sacroiliac joint block, can be a very useful diagnostic test. Of course, it takes a very skilled physician to be able to insert a needle into the correct portion of the joint. Since this is the case, an x-ray is usually used to guide the needle to be sure the joint is properly injected. In some cases, a dye will be injected so that the joint can be better visualized- this is called an arthrogram.
In this test, a live x-ray is used to visualize the insertion of the needle into the sacroiliac joint to inject a numbing solution- lidocaine. If this injection relieves the pain, it can be diagnosed that the sacroiliac joint is actually the source of the pain. Typically, at the same time a steroid solution is injected, which decreases pain and inflammation at the joint.
Treatment for Sacroiliac Joint Pain
Typically, treatments for sacroiliac joint pain are conservative, or non-surgical. The focus is more on working to restore normal motion to the joint itself.
Ice, Heat, Rest
Initially, the recommended treatment for sacroiliac joint pain will include using ice packs in 15 to 20 minute intervals, as needed to reduce inflammation in the area, and rest to reduce irritation. Depending on the duration of intense, sharp pain, ice can be used from 2 days to 2 weeks. Once the inflammation has been reduced, you can return to normal activities gradually. Using heat could help the healing process, but should not be used during the time of acute, intense pain.
Often, the first line of treatment includes pain medications such as acetaminophen and anti-inflammatory medications such as naproxen or ibuprofen to reduce swelling, which contributes to the pain.
A chiropractor, osteopathic doctor, or other qualified physician can provide manual manipulation of the joint- which can be very effective when the joint is “stuck” or fixated. Methods such as side-posture manipulation, blocking techniques, drop technique, and instrument guided methods. Your physician will choose the method that is most appropriate for your case.
When your sacroiliac joint is “too loose,” or hypermobile, a brace about the size of a wide belt can be wrapped around your waist and pulled tight in order to offer some stability to the area. This can be very helpful when the joint is painful or inflamed. When the pain and inflammation goes away, the brace can be weaned away.
Gradual, controlled physical therapy is helpful for strengthening the muscles around the sacroiliac joint and increase the range of motion. Additionally, low impact aerobic exercises will serve to increase blood flow to the area, which stimulates healing. In cases of severe pain, water therapy could be a good option due to the buoyancy provided by the water reducing stress on the joint.
Though the main reason for injections into the sacroiliac joint is to determine if it is the cause of your pain, they can also be used to provide immediate relief of pain. An anesthetic, such as lidocaine is injected in conjunction with a corticosteroid to reduce inflammation, which alleviates the pain. This pain relief can be used to help you start with physical therapy and return to your normal activities.