Beat: my knees

[doubLe a tom]

The other day I played 4 on 4 football (tackle obv cause thats how we roll) and after the first couple plays my knees, well actually right at the very top of the shinbone begin to hurt like hell just to run and I couldnt jump at all. If I tried my legs would just give out. For the next two days I could hardly walk without supporting myself. Getting up from sitting down was especially hard.

I am only 20 and like 6'0 160. So I dont think it has to do with age or weight.

Anybody experience anything like this before?