I was exercising in my room, when I impacted my knee onto the corner of a chair. I was in a "downward dog" yoga position, with my left leg held up high and unbent behind me. I tried to quickly swing it (with a lot of force)so that it would be in between my hands, when i smashed the center edge of my shin directly onto the corner of the chair. It immediately swelled up and changed colors. It is also very painful.. It is like a dull (sometimes sharp) aching pain which is emanating towards my ankle and all the way through my knee. I can walk on it, but not very well.. Is it possible that i fractured it? I know its very difficult to fracture your shin, so I figured I would ask before I went to see someone about it. Thanks!