One of the commonest causes of low back pain is pain from a subluxation (a slippage) of the sacroiliac (SI) joint. This pain is usually felt on either side of your sacrum, the triangular bone at the base of your spine, or just above this area in the space between the spine and the illium, your pelvic bone. It can radiate around your body to the abdomen, into your buttocks or down your legs. The pain can be very severe and incapacitating, can last days or weeks and keep you awake at nights.

What Causes SI Joint Pain?

Your pelvis has to support your whole body. It is composed of three bones: in the middle of the lower back, the sacrum which is joined to the iliac bones on either side of it. The iliac bones are joined together in front by a fibrous joint called the symphysis pubis. In childbirth, the baby which was supported by the pelvis throughout pregnancy has to go through the pelvis in order to be born. As the baby’s head is large, the bones of the pelvis have to separate a bit during childbirth to be able to let the head through. In order to prepare for this difficult passage of the head, the pregnant woman’s body secretes a hormone called relaxin. This hormone relaxes the ligaments which hold the iliac bones on either side of the sacrum together with the sacrum and in front its relaxes the symphysis pubis which joins the two iliac bones together. After childbirth the pelvis may not regain its original strength and the SI joints may slip. Other causes for SI slippage include injuries which can tear the ligaments that hold the joint together and certain movements, such as using your thigh to help you lift a heavy weight which can overstretch or tear the ligaments, and, of course, old age which weakens all ligaments. Ligaments are made up of collagen, the same substance that holds up your skin. Just as your skin sags with age because the collagen under it wastes away, your ligaments also sag as you get older. When the ligaments are not able to hold the sacrum together with the Ilium, the iliac bone tends to rotate forward. Because of this, the spine of the iliac bone (ASIS), which is the hard knob you can feel in the front of your pelvic bone is going to be lower on the side that is giving you pain than on the other side. This movement of the iliac bone overstretches the ligaments that are trying to hold the joint steady and this overstretching is the cause of the severe pain you experience.
Another, frequently overlooked, cause of pain in the low back is pain in the iliac crest area (the top of the iliac bone). There, nerves coming from higher up (the 10th to the 12th vertebrae) have to travel through fibrous tunnels atop the iliac crest to get to the skin of the lower back. A sudden jolt to the back can injure these nerves. Once injured, the nerves swell and get trapped in these tunnels. There they are constantly nerve reinjured as they scrape on the walls of these tunnels, which forces them to remain swollen and to keep sending their pain signals. Often, when the sacroiliac joint is subluxed, the nerves which supply this joint and also supply the skin overlying it gets very inflamed and cause a great deal of pain. At times, people have had surgery to their backs, and where they have been operated on, the scar tissue has contracted around the the skin nerves that supply the area, and trapped them. This is another frequent cause of pain in the back.

The treatment of back pain caused by nerve irritation is perineural injection therapy (nerve blocks). You will receive tiny injections of 5% dextrose or mannitol just under your skin, above these nerves. This will return these nerves to a normal state. This treatment of low back pain is likely to help if your pain is coming from the nerves that supply the skin of your back. Nerve pain can be severe even when you are resting and can be made worse by pressing lightly on the affected areas. Many people suffering from low back pain have been successfully treated with nerve blocks. Because this treatment is very safe, it is worth trying at least once, particularly if your pain has not been helped by other treatments.
There many different treatments for pain caused by SI subluxation. First, try an exercise that will help rotate the Ilium backwards to its original position.

This exercise can be very effective in replacing the Ilium correctly back into the sacroiliac joint. Physiotherapy can teach you stretching exercises for your thigh muscles to stop them pulling the Ilium forward as well as Pilates type core exercises that will help your muscles control the movements of your pelvis. Unfortunately, it cannot restore the strength of the sacroiliac ligaments and the joint is likely to become displaced again.

There are several belts on the market which can help hold your pelvic bones together. Unfortunately, when you remove them, the ligaments are just as loose and the pelvis is likely, once again to become subluxed.
Prolotherapy, by helping regrow the ligaments that stabilize the sacroiliac joint, prolotherapy is extremely effective in preventing the recurrent subluxation of that joint. Dr. Bertrand herself was treated with prolotherapy to her sacroiliac joint six years ago and has been pain free since. A retrospective study published in 2009 of 145 patients with low back pain for more than four years treated with prolotherapy showed that 89% had more than 50% pain relief, 75% were able to completely stop taking pain medication, more than 80% showed improvements in walking, exercise ability, anxiety, depression and overall disability.

Ross A. Hauser, MD, Marion A. Hauser MS RD Dextrose Prolotherapy for Unresolved Low Back pain: A Retrospective Case Series Study Journal of prolotherapy 2009; 3:145 – 155
Acetaminophen, Tylenol, which is a COX3 inhibitor, has a mild anti-inflammatory effect. It, and the NSAIDs aspirin, ibuprofen, Advil, Motrin, diclofenac, Voltaren, have, until now, been the mainstay of treatment to relieve pain. They all relieve the symptoms that occur with overstretched and worn ligaments and tendons. They work by stopping inflammation which is a cause of pain through inhibiting the enzyme cyclooxygenase (COX) which promotes the formation of inflammatory substances. Unfortunately, inflammation is the mechanism the body uses to repair itself, and using these medications interferes with the process which would help regrow the affected ligaments and tendons. All NSAIDs can cause bleeding of the stomach, high blood pressure, and kidney failure, and the COX 2 inhibitors, such as Celebrex, also increase the risk of heart attacks. Nonsteroidal anti-inflammatory references
Narcotics have been given to people with severe pain who, because of liver or kidney failure could not tolerate acetaminophen or NSAIDs.

Cortisone shots in the SI joints being even more powerful anti-inflammatory substances, unfortunately interfere with healing even more than other anti-inflammatory medications. Steroid references

Surgery as a last resort, the iliac bones can be fused with the sacrum. This puts added strain on your hip joints as well as your back and your neck as the sacroiliac joint moves a bit whenever you make a step, acting as a shock absorber.

Prolotherapy References

Low Back Pain Videos

Here are some videos that will help you understand one of the commonest causes of low back pain and how it can be examined and relieved.
What people call low back pain is often investigated and treated as if the pain was coming from the spine when, much of the time, it comes from the pelvis, which supports the spine. The pelvis is the connection between your legs and your spine. When you are walking or running and your foot hits the ground, it sends a shock wave up your legs. If your spine had to be subjected to these repeated shocks, it would soon deteriorate and develop arthritis. Fortunately, your pelvis is there to act as a shock absorber.
How does it do this? Your pelvis is made up of three bones: the sacrum, which is just underneath your spine and acts as a platform to hold up your spine, the right and left iliac bones which are joined to the sacrum and to your right and left hip respectively. The shock of your foot hitting the ground goes up to your hip which transfers this shock to the iliac bone (the ileum) and moves it. When you are walking, your hip rotates your iliac bone a bit towards your stomach or towards your back. This movement is absorbed by the ligaments surrounding the sacroiliac joint (the joint between your sacrum and your iliac bone), so that the sacrum and the spine hardly move when you walk. To get a better understanding of this, watch this YouTube video:
If your right and your left sacroiliac joints are out of alignment, the ligaments which surround the sprained joint will be overstretched and very painful: the nerves inside these ligaments are also overstretched and will send pain signals to your brain. The shock of every step you take will further stretch the ligaments and the nerves inside them, making your pain worse.
Fortunately, there is a way to determine in what direction one your sacroiliac joints is out, and ways to correct the sprain. If your iliac bone has been rotated backwards, towards your back, there is a way to straighten out the joint by pushing backwards on your thigh to pull on the iliac bone to move it forward. Here is a YouTube video you can watch to learn how to find out if your joint is out of alignment. If it is, in what direction. This video will show you how to realign an iliac bone that is rotated backwards: