Sport Science

   Football helmets

It has been widely realized during the past 20 years that the collisions experienced by participants in contact sports and other potentially injurious endeavors are often strong enough to give rise to mild traumatic brain injuries (MTBI) such as concussions.  It is a common occurrence in American football for impact speeds to exceed 20 mph (9 m/s), creating linear head accelerations exceeding 100 g’s and concussion risks exceeding 70%.  This has created a health hazard of epidemic proportions, with several million incidents of MTBI occurring yearly at all levels of play in all sports.  (American football has the highest incidence, and it is estimated that nearly one-third of all retired NFL players will develop some level of long-term neurological disease.).  Although   more protective helmets have been introduced and used by participants in sports and other endeavors, the frequency of MTBI has remained alarmingly high.  It was recently reported that a study of the brains of 111 (deceased) former NFL players revealed that 110 of them had Chronic Traumatic Encephalopathy, the degenerative MTBI caused by repeated blows to the head. 

In response to the MTBI epidemic, we have designed, constructed, and evaluated a new type of football helmet that provides increased protection to users. (This product was developed in collaboration with our partner Division, LLC.) This helmet dissipates a significant amount of the incident kinetic energy arising from an impact, thus reducing the force and torque applied on the helmet, and spreading out the force transmitted through the helmet onto a user’s head. We have constructed a partial helmet prototype that incorporates our energy-dissipating elements, and have used conventional and original testing equipment to demonstrate the significantly increased user-safety that this prototype provides.  A plot of applied force vs impact time is shown in Fig. 4.7.  The blue plot is for the highest STAR rated helmet and the red plot is for our prototype.  The shown applied force profiles are for identical impacts on the two helmets.  Our helmet is seen to significantly reduce the force and extend the impact time.