The sacroiliac joint, is a joint at the bottom of your spine between the sacrum and two ilium pelvic bones on either side of the sacrum. It does not have much range of motion and supports a large part of your body's weight. Sciatica is a nerve impingement disorder of the sciatic nerve, which runs from the sacrum through your pelvis and into both sides of your legs, according to MayoClinic.com. The SI joint is one common site of sciatic pain.
Sciatica Causes
Sciatica comes in many forms, depending on where the nerve impingement or inflammation occurs, according to physical therapist Ron Miller of Spine-Health.com. Most sciatic pain in the leg and hip is caused by herniated disc, spinal stenosis or piriformis syndrome. Herniated disc occurs when one of your vertebral discs between your vertebrae has slipped out of alignment and compresses into the nerve. Spinal stenosis is the narrowing of the nerve tube that compresses the nerve. The piriformis syndrome is the irritation of the sciatic nerve beneath the piriformis muscle that runs parallel with the nerve. All of these disorders cause pain and numbness in your leg and hip when you walk, stand or sit.
Function
The sacroiliac joint functions as a weight bearer for your upper body and as a shock absorber when you run, climb down stairs, and land on the ground from a jump, explains Susan Hall, author of "Basic Biomechanics." It has limited range of motion when you move your hip and spine side to side or bending forward and back. If you have too little movement in your SI joint, you can develop back and hip pain that radiate down to your leg that is similar to sciatica.
Corrective Exercise
Many physical therapy and exercise professionals use corrective exercise to address SI joint pain and sciatica. This method not only addresses the pain symptoms, but also the cause of pain that may be distant from the pain site, according to Anthony Carey of Function First in San Diego. For example, if you experience pain in your right knee when you walk, it can be caused by the lack of range of motion in your SI joint. By performing exercises to increase the mobility in your SI joint and spine, you can alleviate the pain in your knee. Carey recommends that you perform corrective exercises two to three times a day.
Sample Exercise
The supine lumbar rotation exercise increases your SI joint mobility and reduces the symptoms of sciatica. Lie on the ground on your back with your feet together and your knees bent. Put a cushion or folded towel between your knees to help keep your legs together. Move your legs and hips from side to side with your feet still in contact with the floor for 20 reps. Do not lift your lower spine off the ground.
Warning
Never continue to exercise if you experience pain in your back, hip or leg, whether you are weight-lifting, running or doing corrective exercises. Consult with your therapist to see what she can do to adjust your exercise program.
References
- "Pain-Free Program"; Anthony Carey; 2005
- Spine-Health: Sciatica Exercises for Sciatica Pain Relief; Ron Miller
- MayoClinic.com: Sciatica
- "Basic Biomechanics"; Susan Hall; 2003
