Collided shins with friend while playing football. there's no bruise at all but i can't feel anything from the top to the bottom of my shin.

A superficial sen-: -sory nerve may have been injured. Because of no lacerations involved it is called a neuropraxia which means nerve contusion with no disruption of the anatomical make up. These have a great chance of recovery in a few days to a week. If not better it means the nerve must regenerate from the area of injury down. This takes a while, as the progress @ about 1mm/day from the spot of injury.