A new era of helmets?

Materials World magazine
,
1 Aug 2017

A new American football helmet is breaking with design tradition in the run up to the 2017 NFL season, as Ellis Davies reports.

As the NFL gears up for the 2017 season, players have been testing a new helmet – the VICIS ZERO 1. Following the annual NFL/NFLPA Helmet Laboratory Performance Testing, the ZERO 1 has emerged as the top ranked football helmet of the year, implementing a new design that takes inspiration from the automotive industry.  

The University of Washington, USA, has collaborated with Seattle-based VICIS since its formation in 2014, providing research into concussion prevention. VICIS has also worked with neurosurgeons and players to gain a fuller understanding of what is required for both safety and playability. 

ZERO 1 comprises four elements called lode shell, VICIS RFLX, arch shell and form liner, which work together to slow impact forces. Jason Neubauer, VP of product development at VICIS, told Materials World, ‘The lode shell is made of a unique thermoplastic elastomer designed to locally deform while exhibiting durability along the continuum of temperatures encountered during NFL contests.’ This differs from the traditional polycarbonate outer shell, which is inflexible and deflects rather than absorbs impact. The outer shell is supported by the RFLX layer, an engineered columnar structure with omnidirectional capabilities, which is ‘fabricated via a custom method using a cross-linked polymer that is highly resistant to permanent deformation, allowing it to retain its shape and properties across the thousands of impacts undergone by an NFL helmet,’ Neubauer claims.  

The remaining two layers of the ZERO 1 focus on comfort, fit and load distribution. The axis fit system uses a custom aspect ratio (head length and width measurements) to compensate for various head sizes, with an arch shell of hard, rigid thermoplastic to protect against fractures and help to distribute load upon impact. The form liner also distributes pressure uniformly across the player’s head using a combination of memory foam padding and waterproof textiles placed strategically to accommodate head topography.

VICIS has taken an unusual approach with its systematic design. ‘Traditional helmets deploy hard outer shells that spread load, [whereas] the ZERO 1 is a multilayered design architected to reduce linear and rotational impact forces,’ Neubauer said. A standard helmet is engineered to be hard on the outside with soft padding on the inside. The ZERO 1 reverses this convention. The outer layers are soft and malleable, with a hard plastic layer as part of the interior, limiting recoil on impact. When a standard NFL helmet connects with an object, it produces a loud crack as the rigid outer shell resists the impact, often causing the player’s head to ricochet, whereas the soft bendable plastic exterior of the ZERO 1 produces a thud as the helmet deforms to accommodate the impact force. 

Dr Jeff Crandall, engineering consultant to the NFL and chair of the NFL Head, Neck, and Spine Engineering Subcommittee, told Materials World, ‘Historically, a lot of the variation among [helmet] manufacturers has been on the interior lining – whether it’s with an air damper, a pad or thermoplastic polyurethane. What you see with VICIS is an approach that looks at what each of the components can contribute in a systemic way. It’s a very interesting approach, one that is seen in other areas such as the automotive industry.’ 

All helmets entering the NFL must meet standards set by the National Operating Committee on Standards for Athletic Equipment, which are independently certified by Safety Equipment Institute, as well as annual testing by the sport’s governing body, a process Dave Marver, CEO of VICIS , describes as ‘a rigorous evaluation that serves as important validation for the ZERO 1 as we prepare for the 2017 NFL season'.

Crandall spoke about the tests carried out on all NFL helmets. ‘We test at three different impact speeds and eight different impact locations around the helmet using both translational and rotational measurements [...] We also look at the head’s response in angular and linear measures, like accelerations and velocities, and we see how well the helmet is able to mitigate those kinematics,’ Crandall said.

Many biomechanical experts believe that rotation plays a large role in causing concussions, a major issue in the NFL, making the ability to deal with rotational forces a must for new equipment.

A better understanding 

Given the automotive sector’s success in safety methods involving computer modelling and crumple zones, Crandall believes that sports equipment companies could improve protection in similar ways, by learning from and implementing ‘the best practices and state-of-the-art tools and techniques available’.

The NFL has set up various schemes and incentives to promote the development of advanced protective equipment such as the NFL GE Under Armour Head Help Challenge, from which VICIS received funding. ‘We talk about the three Es of injury prevention – engineering, enforcement and education. Rules will continue to play a role in injury mitigation, along with educating players on what behaviour can be risky and what sort of protective equipment should be adopted and worn. The engineering component is not static, but dynamic. We want to outpace the evolution of the game to maintain protection for the players,’ Crandall explained. 

The development of sensing technology could allow designers to keep the on-field environment in mind when designing helmets and other equipment, using data gained from on-field experiences. ‘One of the big pushes of the Engineering Roadmap is to get players instrumented. In conjunction with the Players Association, the NFL is working to develop a new line of sensor technology that could be put on players to gain a much-improved understanding of the types of impacts, by position, that a player will experience,’ Crandall said. This information could then be taken to a laboratory to inform testing, helping to design a helmet that would be optimised for those conditions.