68
many!!
227
Steve Young suffered from 7 diagnosed concussions during his NFL carreer. However the number may have been even higher.
at least 10 maybe more
34 to 100
Nobody knows, but the problem is a concerning one. Many soccer players have been shown to have sustained concussions, especially from repeated 'headers', and concussions (even mild ones) have been shown to be precursors, sometimes, for TBI (traumatic brain injury).
concussions - Many soccer players experience a concussion from hitting the ball with their head.
112
12
20
8
10
there are 3 grades of concussions
8