The sacrum is the bony part at the base of your spine, which consists of a number of fused bones, leading down to the coccyx (tail bone).
On either side of the sacrum you have an ilium - a wing shaped piece of bone which houses the socket part of the hip joint.
The area is swamped with muscles which work the legs, spine, internal bits (sphincter etc ! )
However, your GP is probably referring to a strain of the ligaments which hold the sacrum and ilium firmly together. If these are strained beyond their normal limits you can end up in a lot of pain in the groin / hip/ buttock / sciatic nerve route area.
The 'itis' part of the diagnosis refers to 'inflammation' - of the areas where the damage has occurred.
The degree of injury will dictate the appropriate method of rehab, which is why the doc will have requested further x-rays (although I personally would consider MRI/CT more beneficial as a diagnostic tool.)
At this stage I really think you need to be guided by what the doc tells you, and be careful of running or cycling at the moment because the likelihood is that you may cause further ligament damage from the shearing forces across the sacroiliac joint which those exercises cause.
Rest up for a while, and await the x-ray results and whatever other examinations you have to undergo.
I would expect (barring complications) that you will make a full recovery, just be patient (sorry no pun intended
) and let it heal properly first.
Best of luck for a speedy recovery !
