### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
First if all, let me start by telling you that I have two very pronounced dimples in my lower back. Anyway, about a month ago I noticed a quater sized bruise a little to the right side of my right dimple, it wasnt really painfull or anything that I noticed, it eventually went away, but over the past few weeks I have noticed a knot under the surface that has shown up in the same area, it only hurts a little if I hit it or lay on it, what could this be and any suggestions on ways to treat it or get it to go away? Oh, and I am a dancer, and I do roll on a hard surface over this area quite a bit, not sure if that makes any difference or not. However, the more I roll on it or anything, It swells quite a bit and gets really hot to the touch.

### output:

Hello, Welcome at Chat Doctor. It will be my pleasure to help you. The dimples which are present at your lower back are just the normal landmark of our joint which is known as sacroiliac joint- http://www.youtube.com/watch?feature=player_detailpage&v=D6NTMgWCSaU This is present in normal person. The knot which is present nearby this looks to be an inflamed connective tissue & at this stage better termed as FIBROSIS. In your case this may be due to your dance & rolling habit. Most probably this had lead to injury at this area which had healed with fibrous tissue. You should not bother about this & should consult to an orthopedic doctor for this. Your doctor may give you a good anti-inflammatory analgesic & may use a local steroid injection to give you relief. Hope this will help you Wish you a happy & healthy life.