I can't move my feet after playing soccer--what's causing this?

Over use syndrome: To answer this question with out a full history and physical examination would only be guessing. I would need to know how long did you play, was there swelling, is it because of pain that you can, t move , how soon do you recover, do you have a foot deformity, arthritis etc. It would be best to be examined by a podiatrist.

Cramps: You are probably dehydrated and your muscles are cramping.