Originally Posted by Mark in Idaho

My concern about the 'neck strengthening" hypothesis is that is can cause a false and dangerous sense of security. I highly respect Dr Robert Cantu. He has been at the forefront of concussion issues for quite some time. He and the others are still researching this "hypothesis."

Unfortunately, Dr Cantu, in his comment "It's just straight physics. If you see the blow coming and you have a very strong neck and contract the neck muscles, you have a much greater chance to have significantly reduced the forces the brain will see." is dead wrong about the physics.

As I said before, When you change how the head and neck absorb or react to the impact, all you have done is change the way the impact force is transmitted into the skull in the aspect of whether a coup contra-coup injury will be caused and the timing of the shock wave. Whether the shock wave differences reduce the injury or increase the injury will be based on a myriad of other factors. The most important factor is whether the helmet has an ability to deform, thus absorbing some of the energy. Otherwise, helmets are most useful at preventing broken skulls, not impacted brains.

I understand the desire and focus on reducing the risk of concussions but neck strengthening is not going to change this risk. The multiple concussions received in contact sports will continue until there is a radical change in how the head is or isn't subjected to impact forces.

A simple way to understand this is with vehicle collisions. In the 60's, cars were built with stout bumpers and frames. They reduced damage to the vehicle but transmitted higher forces to the occupants. The rebounding bumpers of the 70's and 80's absorbed some of the energy but the spring back of the rebound bumpers caused a secondary force against the occupants.

The current crash worthiness technology depends on a progression of collapse of 1st, the body panels, next, the sub-structure, then the frame. All of these structures are "destroyed" as they protect the passenger compartment from the g forces that can be so damaging.

Bicycle helmets use a similar process. The semi-hard foam is broken or deformed thus absorbing the impact forces over a longer period of time.

Force = mass x acceleration. Acceleration is a measure of change in motion over a specific period of time. If the impacting force from the opposing player stays the same, the only thing that can be changed by the impacted player is the amount of time in the acceleration formula.

Contrary to Dr Cantu's claim. The impacted player can diffuse the energy by reacting with a change in his own movement to try to match the impending movement of the impacting force. If he is pulling his head/helmet back as the impacting player is impacting his helmet, the differential at time of impact will be less. This will reduce the injuring forces.

Last example. Lay a piece of glass on a hard flat surface so it can not move at all when impacted. Then hit is with a rigid object. Even though the glass does not move, the shock wave from the impact will still break the glass. If the glass can move just a bit, it will be more likely to just crack. If it is held firm, it will more likely shatter. The difference is just the timing of the impact force and shock wave.

So, get a helmet that absorbs the impact on the outside layer to reduce brain forces.

Soccer players will strengthen their necks for better abilities to head the ball. These players will still suffer the statistical loss of 9 to 10% of their IQ level from heading the ball.

The Law of Physics is call "Conservation of Energy." Energy can neither be lost nor gained. The energy of the impact is just transmitted through the body parts.

'Nuff said.