[81alum]

Lots of sports have concussions, but the latest evidence is that concussions are not the only problem...or even the main problem.  It appears to be the constant accumulation of sub-concussive injuries that keeps the brain inflamed and leads to much of the damage.  Those come from inertia changes that throw the brain around within its sack of fluids and which often go completely undetected as an injury.   Even a completely normal tackle or just falling down could contribute.  It is a little like deafness, which can result from a few extremely loud sounds, but which more often results from the constant drone over long periods of time of less loud sounds.
 
At my university, water polo and gymnastics had a higher incidence of concussion protocols per participant than football.  But those sports might well have fewer of the sub-concussive events--who knows?  It needs to be studied, which is the whole point of those mouth guards that measure change of direction that we were using.

[81alum]

Lots of sports have concussions, but the latest evidence is that concussions are not the only problem...or even the main problem.  It appears to be the constant accumulation of sub-concussive injuries that keeps the brain inflamed and leads to much of the damage.  Those come from inertia changes that throw the brain around within its sack of fluids and which often go completely undetected as an injury.   Even a completely normal tackle or just falling down could contribute.  It is a little like deafness, which can result from a few extremely loud sounds, but which more often results from the constant drone over long periods of time of less loud sounds.
 
At my university, water polo and gymnastics had a higher incidence of concussion protocols per participant than football.  But those sports might well have fewer of the sub-concussive events--who knows?  It needs to be studied, which is the whole point of those mouth guards that measure change of direction that we were using.