Hairless bump/Callus on my Lab's right hock?

I took my dog to the dog park today and as she romped around and jumped on the doggy obstacles and such I noticed that she had a bare (hairless) patch on her right hock. I immediately came home and I took a look at it. It causes her no pain whatsoever, doesn't look infected, but nevertheless, it is there. My dog sleeps in her crate with her cushioned dog bed, she is an inside dog. We do have carpet in our rooms, but its the rather thin carpet, the rest of the house is all tile.

She has this specific was she likes to lay in which she stretches her right rear leg (the leg in question) straight... it seems she is very comfortable in this position, and it clearly puts pressure on that area.

I guess this is rather common in medium-large dogs (my dog is a small lab) and my question is, what can I apply on it to help it heal?

* I will post pictures as soon as I can.
Thanks