“My pelvis goes in and out of place!” or “my sacrum has gone out!” can be common beliefs for people who suffer from pelvic or lower back pain. This topic was discussed by Dr. Peter O’Sullivan, one of the leading back pain researches, in a recent BJSM podcast.
As it turns out, up to date research would suggest this is an illusion and there is no evidence to prove that the pelvis or sacrum can in fact go in or out of place, or anywhere else for that matter!
The facts based on research are as follows:
1. The pelvis and the sacroiliac joint (SIJ) joint are very secure and stable joints and move very little.
- In a non-weight bearing or lying position the SIJ has on average 2.5 degrees of rotation or movement.
- In a weight bearing position i.e. standing the SIJ has on average only 0.2 degrees of rotation or movement.
- The ligaments that hold the SIJ in place are one of the strongest in the body!
- The pelvis is designed for load and weight transfer through the body and in order for the pelvis to efficiently do its job minimal movement in the joint is optimal.
2. Given how little the pelvis moves, if the pelvic joints are not moving ‘correctly’ this fault cannot be reliably detected on physical examination.
3. Manipulation of the pelvis does not alter the position.
- A study conducted where the pelvis was X-Ray pre and post manipulation showed no difference in structure or alignment, i.e. the manipulation had no effect on the position of the pelvis.
- Manipulation can offer pain relief and make the pelvic ‘appear’ to be moving differently – however this is more than likely due to a decrease in tension in the tissues surrounding the joint following the manipulation, rather than a change in joint position.
The question is then if the SIJ has minimal movement and does not go out of place, why does the pelvis look higher on one side or why is the pelvis twisted?
The answer is that a change in muscle tension, length or function in the lower back musculature or a muscle around the pelvis such as the buttock (gluteal) muscles can alter the position of the pelvis by placing a directional strain on the pelvis but the evidence has shown and proven that the actual joint itself has NOT moved and is still in the exact same place. This suggests it is the muscular environment in which the pelvis operates that we must consider and treat if needed.
There has been a lot of talk recently in relation to Tiger Woods, his operation and his road to recovery. He has tweeted and wrote blogs on his experience. However some of the terminology that he used is controversial and Dr. Peter O’ Sullivan discusses in his very interesting podcast these misconceptions.