Thanks sooo much for this very helpful response. I first noticed the problem for a few minutes ,while trying to get up from a sitting position about 3 months ago. I just found getting up very painful. It was a one off experience and seemed to disappear. Later I started noticing a dull but sharp pain almost in the center of my bum about where the buttocks separate. For a while the pain was only when I was sitted and became very dull and almost none existent when I stood up. I don’t have pains in either legs because I also searched online trying to relate it to the suggestions ( sciatica, pri…..) made there. It didn’t seem to match any of those. I also cannot remember any incident that could triggered it. I have had an history of spondylitis in my neck but I have not had the pain in my neck and left arm in a long time. I thought perhaps this new pain is related to spondylitis after reading something online yesterday. Yesterday also on closer examination by my partner, we concluded the pain was down the middle of the left butt. It was painful to touch and even sitting down now, I tend to bend to the right. It does ease up when I stand and might be related to the tailbone. I will try the exercises you suggested for starters . Thanks very much.