The formation of the sacroiliac joints (SI joints) is the result of the sacrum (tailbone) connecting to the left and right parts of the iliac (pelvis) bones. These joints are stabilized by strong ligaments and are not joints that have much range of motion. This is because their main role is in supporting the weight of the upper body when erect and sitting. Because of the high demand of the joint it is common to have some problems that result in SI joint pain.
Commonly when things go wrong with this joint it is called sacroiliac joint dysfunction and usually means there is SI joint pain. It is also called SI joint syndrome, SI joint inflammation and SI joint strain. These are all variations on a theme of problem of this joint.
There are many causes of sacroiliac joint dysfunction. It is a joint like any other joint in the body and therefore prone to wear and tear. Osteoarthritis commonly happens in this joint because it is weight bearing in nature. As a result the cartilage on the bone surfaces, which acts like a shock absorber will wear away and the bone will rub on the bone causing pain.
Another common cause of SI joint pain is pregnancy. During the stages of pregnancy the body releases special hormones in preparation for childbirth that help relax the ligaments. The resultant relaxing of the SI joint structure and increased pregnant bodyweight can cause problems. Add on top of this the changed walking and standing posture of pregnancy and you have a recipe for SI joint pain.
Also any change or problem in the lower half of the body that disrupts the walking or gait cycle could cause SI joint problems. A leg length discrepancy, where one leg is longer than the other can do this. Also any injury to the lower back, foot, hip, knee or ankle can all result in a abnormal pattern of walking that places undue stress on the SI joints and causes SI joint pain.
Females seem prone to SI joint pain. This could be due to slight anatomical differences in the hips and pelvis. Two aggravating factors are known. Often when females sleep on their sides, the wider hip width means the top thigh drops down a lot. This put extra strain on the SI joint by opening it up. One solution is to sleep with a pillow between your legs and this should help the SI joint pain. Also sitting cross legged does a similar thing. It opens the joint and places uneven stress on it often for prolonged periods. The result is commonly SI joint pain. The solution is simple but may take some getting used to: stop sitting crossed legged.
Physical therapy for SI joint pain can be great. Yoga and pilates offer excellent benefits. Improving flexibility in stiff and tight areas can help reduce any compensation of the SI joints. Also building core stability can go a long way to helping take any excess stress off the SI joints. Remember the benefits and changes in the body may not be felt immediately with these activities, so it may require a slight commitment before you reap the rewards.