Thomas A. Gennarelli, M.D. and Lawrence E. Thibault, M.D. concluded that angular acceleration contributes more than linear acceleration to concussive injuries, diffuse axonal injuries, and subdural hematomas. Angular acceleration is the cause of rotational brain injuries. Rotational brain injuries can be serious, long lasting, and life threatening.

Experiments conducted by David C. Viano, PhD. M.D. and the Bioengineering Center at Wayne State University confirmed that a helmeted head sustained the same degree of angular acceleration as the

un-helmeted head when subjected to identical impacts. So, if angular acceleration is the major cause of brain injury, then how is the brain protected by traditional helmet technology? Unfortunately, in the aspect of angular acceleration, it is not.

The focal point of traditional helmet design has always been directed at providing protection against linear impact energy test compliance. Helmets are tested to standards by dropping them in a vertical plane on very complex test equipment in a controlled environment. This testing assures the public that a level of compliance is achieved before a particular helmet makes it to market. While this is an excellent control method, impacts in a ‘real-world’ accident are in fact much different, and the impact will almost certainly be an oblique angle strike. This means the helmet will impact an object or the ground at an angle greater or less than 90 degrees to the center of mass (the brain) within the helmet. During this event ( impact ),
angular acceleration is transferred to the brain. 6D’s goal is to reduce this angular acceleration transfer thereby reducing the potential of brain injury. ‘ODS™’ achieves this goal. In some test cases, the 6D ATR-1 off-road helmet reduces resultant angular acceleration over traditional helmet design by over 80%, resulting in a truly revolutionary helmet.

6D’s ODS™ equipped ATR-1 helmet delivers the best of all worlds; a helmet with great low-threshold energy compliance, mitigation of angular acceleration, and required high-energy performance all in one certified helmet design.

Peak resultant linear

Peak resultant angularAngular acceleration formula