Bones protruding out on shin under knee caps?

Recently I've just noticed that I have these bones protruding out of my shin right under my knee caps, is it at all normal? Does anyone else have them?

I just noticed these after I added squats and lunges to my workout routine a month ago. I thought at first it was strange but now my left leg is in pain at the protrusion (after bumping it into a chair in the middle of the night).

Anyway does anyone know what these are and possible a medical explanation?