In contact sports, head impacts are a major issue. The newly developed helmet may play key role in decreasing brain injury risk.
Liquid shock absorbers containing helmet decreases the impact of head blows by a third in football players, said Stanford University scientists (1✔ ✔Trusted Source
Finite element evaluation of an American football helmet featuring liquid shock absorbers for protecting against concussive and subconcussive head impacts
Go to source). “Most of the members of our team have a personal connection to traumatic brain injury and we care deeply about ensuring long-term athlete brain health,” said Nicholas Cecchi, a PhD candidate at Stanford University and lead author of the study in Frontiers in Bioengineering and Biotechnology.
‘In football players, the newly designed helmet with liquid shock absorbers helps decrease head impacts.’
Previous research by the Camarillo Lab at Stanford University had suggested that liquid shock absorbers could provide improved protection in sports helmets. To investigate this, the team built a finite element model, used by engineers to simulate performance before manufacturing, of an American football helmet incorporating 21 liquid shock absorbers. This helmet was tested against simulations of the helmet performance evaluation protocol used by the National Football League (NFL), its performance compared to that of four existing helmets.
Protecting American Football Players from Injury
Due to the mounting evidence that the cumulative effect of impacts which don’t cause diagnosed concussions can also have serious health consequences, the team added lower velocity impacts to the evaluation protocol. They measured the head kinematics for each impact to produce a Head Accelerate Response Metric (HARM) score, which is used to evaluate helmet performance under impact. The kinematics were also fed into a model of the head and brain to gauge the resulting strain on the brain.The helmet with liquid shock absorbers performed better than the existing helmet models, producing the lowest HARM value in 33 out of 36 different impact conditions tested, with an average reduction in score of a third. The liquid helmet also had the best ‘Helmet Performance Score’, a measure used in the NFL’s annual helmet safety rankings, which includes a weighting for how well a helmet protects against blows in different areas of the head.
The highest-weighted location is the ‘side upper’ portion of the helmet because impacts here are most likely to cause concussions: the helmet with liquid shock absorbers reduced the HARM score in this area by 39-50% across all impact velocities without compromising protection in other areas of the helmet.
“The liquid technology offered an average improvement of over 30% for both low and high velocities,” said Dr. Yuzhe Liu, corresponding author, who completed the work as a postdoctoral scholar at Stanford University. “It can dramatically reduce the loading on the brain that is experienced during all kinds of American football impacts.”
The team intends to develop the model significantly to protect players better – for instance by incorporating improvements to the facemask and chinstrap. They also plan to develop the model into a physical helmet that could be tested in real-life conditions, and in the future to produce similar helmets for other sports. However, different levels of play or different sports may need assessment by different metrics and design redevelopment.
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Reference:
- Finite element evaluation of an American football helmet featuring liquid shock absorbers for protecting against concussive and subconcussive head impacts - (https://www.frontiersin.org/articles/10.3389/fbioe.2023.1160387/full)