The pelvis is made up of three bones – the sacrum in the middle and an Ileum on each side. The sacro iliac joint is found at the back where the two ileums attach onto either side of the sacrum.
The sacro iliac joint is unusual in that it is two irregular surfaces of bone that are held together by a thick fibrous skirt. It is not a ball and socket like the hip.
There is little motion, approximately 5 degrees maybe, as the leg come from behind to in front. However it is the top end of a long lever, the leg. Physics tells us that a small amount of motion at one end of a lever has a large effect at the other. If therefore the sacro iliac joint becomes jammed and does not move fully the effects on the leg are dramatic.
The main symptoms are:
- Tightness in the upper hamstring
- Tightness in the gluteal or buttock region
- Possibly soreness in the lower back, but not often
The history is often not clear. There is rarely an ‘ouch’ moment. However episodes in my experience are often caused by;
- Missing a step – a jarring
- Poor core and the pelvis tipping forwards
- Running with poor pelvic stability
Physios look at the joint mobility and assess for dysfunctions. There are several ways in which it becomes ‘stuck’. The majority of these joint dysfunctions require mobilisation of the sacroiliac joint by your Physio. You often have tightness in muscles like Piriformis, deep in the glut, as well as in the fibrous tissues around the pelvis. This depends upon how long the joint has been dysfunctional. This will need mobilisation.
Once the joint is moving properly you need to keep it moving with exercises prescribed by your Physio. Further you will need to work on the reasons why the problem occurred to begin with. Weakness and tightness around the pelvis and the lower back as well as other muscle imbalances are the first port of call. All of these will be looked at by your Physio and a plan of attack worked out.