Rotational Acceleration
A circular force that has a fixed pivot point
Figure 1: The Old-style Headguard is not a Helmet
Figure 2: The Old-style Headguard Concussive Cycle
Impulse Concussion: The Second Type of Concussion
Almost without exception, when a linear force is applied to the head, it turns into a rotational force, this is why concussions are generally associated with rotational acceleration.
When your neck acts as a pivot point during a force, such as a punch to the head, it whiplashes backwards. Since the head moves around a pivot point (the neck), the force, depending on how fast it moves, adds to the momentum force. Momentum is described in physics as the mass of an object multiplied by its velocity (speed and direction). Simply put, momentum is all about how hard it is to stop something from moving or how fast it can go when a force is applied. Heavy and faster objects have more momentum, while lighter and slow objects have less.
When this definition is applied to the head, as the head is attached to the neck and rotates, this rotational action increases the force of the hit, creating inertia in the brain. In this case, the inertia that is created in your brain, within your skull, wants to keep moving until something stops it.
When the neck cannot bend backwards anymore and hits your shoulders, your skull stops, the brain crashes into the back of the skull, stopping it, potentially bruising the brain in the process and causing an impulse concussion. Shaw (2002) states: “Impulse refers to an accelerative force which sets the head in motion without directly striking it" (p. 288). In this case the brain within the skull absorbs momentum and speed from the whiplash movement of the head giving the brain inertia which is stopped by the skull causing the concussion or bruising of the brain when the skull stops. “Thus, in ordinary events, the fighter with a fixed head is not concussed. From this observation, and from the billiard ball and toy experiment, it is not the transfer of kinetic energy per se, but the absorption of kinetic energy, the last ball, or the release of kinetic energy, the first ball, that results in a jarring that will concuss" (Parkinson, 1982, p.137-138).
Key takeaways:
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The neck, being a pivot point promotes momentum. The heavier the head and headguard, the more momentum and inertia are transferred to the brain, leading to increased potential for a concussion and neck strain.
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Without a way to transfer the energy from a hit away from the brain, a secondary concussion (impulse concussion) can occur when the brain crashes into the back of the skull.
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Old-style headguards add weight to the head, increasing the potential for a concussion. Top heavy helmets (high center of gravity) promote and add to head momentum.
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If the force is great enough to cause an impact concussion, it is probable that the person will also suffer an impulse concussion and possibly a neck injury.
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Reducing movement or acceleration of the head/brain is important in reducing concussion potential.
Warrior Tough Concussion Counterpunch helmets are designed to change the pivot point from the neck to the helmet creating a bridge from the head and neck that transfers energy away from the brain. The Concussion Counterpunch helmets are specifically made with a low center of gravity, so its weight does not add to the concussion equation against the athlete like a top-heavy headguard.
Warrior Tough Concussion Counterpunch Helmets Transfer Kinetic Energy to Deal with Rotational Acceleration
To eliminate whiplash as much as possible, we significantly reduced the area where whiplash occurs. This new design allows the head to move freely for a shorter distance while significantly reducing the area needed for rotational energy to build. Mathematically, this means it would take a harder hit to reach the concussive threshold because the area for acceleration has been reduced.
After being hit, the back of the helmet (known as the safety stop) automatically makes contact with the shoulders. This built-in safety feature initiates the energy transfer process but also considerably decreases the whiplash movement of the head, reducing the potential for neck injuries.
This enhanced design feature adds support to the neck and reduces the trauma of the impact. In this way, we designed the helmet to absorb and transfer force to benefit the athlete.
Whiplash movement
