Do Helmets Prevent Concussion?
John D. Lloyd, Ph.D., M.Erg.S., CPE, CBIS
Board Certified Ergonomist | Certified Brain Injury Specialist
32824 Michigan Avenue, San Antonio, FL 33576
Tel: (813) 624-8986
Concussion, also known as mild traumatic brain injury (mTBI), is a leading health issue resulting from head impacts associated with sports, recreation and transportation. Youths are particularly susceptible to head injury, though it can also devastate a professional career. Full recovery from mTBI often takes longer than expected, without which a second, even relatively innocuous, impact could have catastrophic outcomes.
Helmet manufacturers realize that their products may not reduce the risk of concussion and even NOCSAE (National Operating Committee on Standards for Athletic Equipment) standards are based on tests that ignore risks associated with concussions. Yet, clinicians recognize that brain injuries are caused by a combination of impact and impulse mechanisms, which engineers are readily able to measure in terms of linear and angular head motions.
Dr. Lloyd, a leading researcher in the field of biomechanics of head and brain injury, has conducted a biomechanical evaluation of the leading sports helmets, the results of which explain why certain types of helmets and impacts are more likely to result in significant injury.
BRAINS Researchers Reveal Deficiencies in Football Helmet Design
Researchers at BRAINS, Inc. have conducted biomechanical tests revealing the deficiency of current football helmet designs in protecting players from brain injury, particularly concussion.
Historically, helmet effectiveness has been measured through drop-tests, using a device approved by the National Operating Committee on Standards for Athletic Equipment (NOCSAE). The result is helmets that are optimized against skull fractures, bruising, and other focal effects. “We modified the standard test device to consider rotational acceleration in addition to conventional linear impact measures” explains John Lloyd, PhD. Biomechanical researchers have long understood that angular forces can cause serious brain damage including concussion, axonal injury, and hemorrhages.
Using proprietary miniature sensors to measure concussion risk at the center of the brain, BRAINS researchers completed more than 330 tests across ten popular helmet brands. The team concluded that while these helmets provide excellent protection from linear impacts – those leading to bruising and skull fracture – they offer little or no protection against angular acceleration, a dangerous source of brain injury and encephalopathy.
Results show percent reduction in linear impact acceleration, Head Injury Criterion (HIC), and angular acceleration provided by the different football helmets, compared to the same impact with no helmet. Note that all helmets provide considerable protection from skull fracture (blue) and focal brain impact (green), but are far less effective at reducing risk of diffuse brain injury and concussion and encephalopathy (red). In fact, some helmet designs offer no significant protection from concussion — and those that offer the least protection are among the most popular on the field.
The following table presents a ranking of the more popular football helmets, from best to worst, based on their combined protection from skull fracture, focal brain impact and diffuse brain injury.
Protection against concussion and axonal injury is especially important for young players, including peewee, high school, and college participants, whose still-developing brains are more susceptible to the lasting effects of encephalopathy. Therefore, the need to develop headgear to protect susceptible individuals from life-changing brain damage is paramount.
Consistent with their innovative approach to meeting the challenges of brain trauma, combined with 20+ years of experience in biomechanics, and neurophysiology, BRAINS researchers have investigated several new technologies to measure and reduce the debilitating effects of concussion in football players. The team is poised to integrate their new technology into helmet design – a paradigm-shift in helmet construction – and bring to market a more comprehensive form of head gear to defend against catastrophic brain injuries while also mitigating linear forces associated with impact.
For further information, please contact :
John Lloyd, PhD | 813-624-8986 | DrJohnLloyd@Tampabay.RR.com
Researchers Discover Objective Indicator of Concussion:
Lends to opportunity to Protect Professional and Youth Sports Players from Traumatic Brain Injuries
Brain Injury researchers teamed up with football players at a Florida high school. Ten players were equipped with Riddell Revolution Speed helmets, with the embedded Simbex HITS encoders, which were worn throughout the 2011/2 football season. The HITS system recorded the severity and location of all head impacts during both football practice sessions and games.
To measure the physiological effects of acute and cumulative head impacts, players agreed to wear a wireless EEG system, which was housed on the back of the shoulder pads. In addition, heart rate variability, respiration rate as well as linear and angular motion was recorded using a Tricorder developed by ReThink Medical.
During the 2011/2- football season, several concussive level impacts were recorded. Two players were removed from the field due to suspected concussion / mTBI, one of whom was wearing the complete data acquisition system, including HITS encoders, Nicolet EEG and ReThink Tricorder at the time of impact and for approximately 30 minutes post-impact. For the first time we have the opportunity to investigate physiological responses and brain activity changes in response to a concussive level head impact.
Analysis of one player’s self-reported concussive impact clearly shows decreased Gamma band activity and increased Theta band activity in the frontal cortex of the brain immediately following significant head impact. This suggests that the player had reduced cognitive performance and was perhaps in a ‘drowsy’ state for about 10 minutes following impact. During this time, the player may have been dazed and confused and certainly less effective on the field. But more importantly, his ability to protect himself from a second, potentially harmful impact was greatly compromised.
The findings of our study clearly indicate compromised brain activity as a result of head impact, which appears to be correlated with the magnitude of the impact
Our future goals for the 2012/3- football season include a new micro-EEG recorder, which is in development, that will allow unobtrusive measurement of several players simultaneously during both football practice and games.
Ultimately, it is our hope that this technology will be widely available to both professional and youth teams so that medical staff can monitor the brain health of players in real-time so that injured participants can be objectively identified, effectively protected and successfully treated.