By: Dr. Brian P. Kinmartin, PPT, DPT, MTC, OCS, STC, CWcHP, Cert. DN
A painful sacroiliac joint is one of the more common causes of mechanical low back pain. At the base of the spine lies the sacrum or tailbone. The sacrum is a triangular shaped bone that is formed early on in development by the joining of several vertebrae. The iliac bones are the two large bones at waist level that make up your pelvis. The sacroiliac (SI) joint sits between the sacrum and the iliac bones (thus the name "sacroiliac" joint). These joints are visible from the outside as two small dimples on each side of the lower back slightly below belt level.
The SI joint is one of the larger joints in the body; the surface of the joints may be irregular as they fit together. A small amount of motion occurs at the SI joint, but the motion that does occur is important for normal trunk mobility. As motion occurs, it is usually a combination of sliding, tilting and rotation in different planes. The SI joint is held together by several large, strong ligaments in the back of the pelvis. The pelvis is designed like a ring with these ligaments working together to maintain the integrity of the pelvis, if these ligaments become torn or overstretched the pelvis can become weak and unstable. This can happen with any injury to the pelvis, such as fractures, sprains or overuse injuries.
There are many different causes of SI joint pain. The SI joint becomes very mobile in women at the end of pregnancy as delivery nears, the hormones that are produced causes the joint to relax. This allows the pelvis to be more flexible for the birthing process. Multiple pregnancies seem to increase the mobility of the SI joint and the amount of arthritis that forms in the joint later in life. A difference in leg length may contribute to SI joint pain, the abnormal alignment in standing and walking may end up causing excessive stress resulting in SI joint pain. Injury to the SI joint is thought to be a common cause of pain. One example of such would be during an automobile accident. A common injury to the SI joint occurs when the driver of a vehicle places one foot on the brake before a collision. The force directed up through the leg can result in a sprain to the ligaments in the pelvis surrounding the SI joint.
After the diagnosis of SI joint pain is made by your medical practitioner, one form of treatment may be referral to a Physical Therapist. After evaluating your condition, a therapist can assess the type of SI joint dysfunction and instruct positions and exercises to facilitate your recovery. When movement of the SI joint is limited, the pain and symptoms of SI joint dysfunction may worsen. Returning mobility to the joint can give relief. Physical Therapist's have several ways to help restore the proper mobility to the SI joint. Some therapists are trained in manipulative techniques to treat SI joint pain through repositioning. With physical therapy for the loss of SI joint mobility the combination of manipulation and exercise seems to provide the best results. If the SI joint has too much mobility and the symptoms keep returning, you may need extra help to stabilize the SI joint. Your therapist may issue a SI belt to assist in stabilizing the joint. A belt like this can offer support allowing the ligaments to heal or tighten, easing the pain and facilitating the rehabilitation process. Your therapist will then instruct exercises to help build strength, muscle control, and endurance in the muscles that attach around the SI joint.
Dr. Brian P. Kinmartin, PPT, DPT, MTC, OCS, STC, CWcHP, Cert. DN, owner of Professional Rehabilitation Services in Pawleys Island, South Carolina is board certified in orthopedics and is a certified manual therapist, trained in manipulation of the spine, pelvis and extremities. For further information on this topic or questions about obtaining a referral or making an appointment at Professional Rehab, please contact Brian at (843) 235-0200, or at www.prsrehabservices.com