[BostonCard]

One thing I've never understood from a physics perspective:  Why not have padding on the outside of helmets?

The padding on the inside helps when recieving hits, but having, say, 1/2" of dense foam around the helmet could increase time of impact (reducing impulse) and spread out the area of impact (reducing pressure) for both recieving and delivering hits.

I'm sure this wouldn't solve the problem, but it seems like an easy step in the right direction.

Concussions are not caused by the impact per se, but by the sudden acceleration and deceleration of the brain within the skull.  Perhaps counterintuitively, there is at least as much of a risk to the brain tissue on the opposite side of the point of impact (the countercoup) as their is to the area directly under impact (the coup).  Thus, spreading the impact over a wider area won't prevent head injury, although an additional layer of foam might absorb energy and reduce the internal forces the brain is subjected to.  It is worth noting, however, that a large portion of head injury in a concussion is due to rotational acceleration/deceleration (thus, rotational forces) and not linear forces.

http://en.wikipedia.org/wiki/Countercoup

BC

[BostonCard]

One thing I've never understood from a physics perspective:  Why not have padding on the outside of helmets?

The padding on the inside helps when recieving hits, but having, say, 1/2" of dense foam around the helmet could increase time of impact (reducing impulse) and spread out the area of impact (reducing pressure) for both recieving and delivering hits.

I'm sure this wouldn't solve the problem, but it seems like an easy step in the right direction.

Concussions are not caused by the impact per se, but by the sudden acceleration and deceleration of the brain within the skull.  Perhaps counterintuitively, there is at least as much of a risk to the brain tissue on the opposite side of the point of impact (the countercoup) as their is to the area directly under impact (the coup).  Thus, spreading the impact over a wider area won't prevent head injury, although an additional layer of foam might absorb energy and reduce the internal forces the brain is subjected to.  It is worth noting, however, that a large portion of head injury in a concussion is due to rotational acceleration/deceleration (thus, rotational forces) and not linear forces.

http://en.wikipedia.org/wiki/Countercoup

BC