Selecting a Head and Neck Restraint; A Practical Guide of What to Look For
Over the past several months I have seen more and more posts on message boards questioning which head and neck device is best suited for a driver’s individual needs.  This is a question I recently posed to Trevor Ashline, safety engineer and developer of the Hutchens Device and the Simpson’s D-Cel.  Although I guess I would be disappointed if  Ashline’s response was not biased towards his own products, I do feel his response carries a certain amount of credence since he always  bases them on both laboratory testing and his years of experience in driver safety.

Purpose
Before we can begin a comparison of head and neck restraints on the market today, it is helpful to understand the purpose of a head and neck restraint.  In most basic terms the purpose of a head and neck restraint is to reduce neck tension in frontal and angular impacts.  The head and neck restraint should also benefit the driver in other types of impacts such as roll-overs and accidents involving multiple impacts.

The Value of Testing
As additional manufactures of safety equipment begin turning out head and neck restraints it is important to evaluate how well these devices have been tested.  Ideally you would like to to find a manufacture whose testing has included both laboratory and real-world (on-track testing).  Ashline is quick to point out that each of these testing environments provides a safety engineer with valuable data.  “The laboratory is valuable because it allows us to perform multiple tests in a controlled environment where we are able to gather data and visually watch the forces at work on a driver in an impact.  The downside of laboratory testing is that it is a controlled environment under ideal conditions.  In real-world racing situations, there are additional dynamics at work.  Often you are dealing with seats, belts and other safety devices that might not be properly installed.  Additionally the angles of impact produced in a real-world accident might not be easily duplicated in a sled test,” explained Ashline.  The unfortunate part about real-world testing is that it means that someone had to crash.  With this said, it stands to reason that only those head and neck restraints that have been on the market for some time have enough of a history to have been put to the test in a significant number of real-world situations.  

As one of the first head and neck restraints on the market and one of only two (head and neck restraints) that have been approved for use in NASCAR competition, the Hutchens Device has been put to the test in hundreds of real-world crashes.  These crashes have occurred in everything from stock cars to sprint cars to Bandoleros.  Furthermore as proven by the test data, the Hutchens Device has undergone extensive sled (laboratory) testing in a certified laboratory.  Ashline comments, “A number of commercially available head and neck restraints have little, if any testing in a certified laboratory.  What works in theory, seldom works the way the inventor intended in all situations.”

Types of Head and Neck Restraints
There are three primary types of head and neck restraints.  The strap type head and neck restraint which utilizes the driver’s body as an integral part of the anchoring system.  Both the Hutchens Device and the Simpson D-Cel are considered strap type head and neck devices.  The second type of device attatches to the drivers seat belt to assist in the restraint of the head and neck.  The HANS Device and SRS-1 are examples of this type of device.  The final type of device utilizes some anchor point such as the chassis or a seat belt as part of the restraint system. 

Advantages and Disadvantages
Which device is best?  Although not easily answered, Ashline helped direct us towards some considerations and facts that might help.  “The strapped devices have proven effective in reducing neck strain in frontal and angular impacts.  Since they don’t rely on the seat belts to restrain the head and neck, they don’t become dislodged or loosen the belts upon impact.”  In laboratory tests head and neck restraints that rely on the seat belt as part of the restraint system have come loose upon the initial impact.  The strapped devices have never failed in a laboratory sled test,” commented Ashline.  There is a record of injuries among drivers involved in multiple impact crashes while using a seat belt restrained head and neck device, that dates back to the early 90s.  While addressing a group of ASA drivers, Bob Hubbard of Hubbard Downing reported to drivers that their have been incidences of the belts coming off the HANS Device during racing conditions.

Research has also concluded that devices that ride with the occupant in the event of an impact are most effective.  Devices which rely on external anchor points like the cars chassis or seat produce unpredictable results in off angle or multiple impact situations.  “Since you are now also relying on the integrity of additional lesser known components of the safety system like the chassis or even the seat, it becomes much more difficult to predict the effectiveness of the head and neck restraint.  For instance, if the head and neck restraint is anchored to the seat, and the seat fails, the head and neck restraint also fails,” commented Ashline.  The Hutchens, D-Cel and HANS are all devices that ride with the occupant in the event of an impact.  This maintains the relationship between the head and torso during an impact, decreasing the risk for serious injury.

Another important consideration when evaluating head and neck restraints is the materials they are constructed from.  Different materials have demonstrated different elongation (stretch) characteristics in laboratory testing.  The lower the elongation the lesser the risk for serious injury.  Both the Hutchens Device and the Simpson D-Cel have begun using polysester instead of nylon because of the superior resistance to elongation deomonstrated.  An added benefit is that the polyester also shows better wear characteristics and does not stretch when it gets wet.  The benefits of polyester are not only making it the choice for head and neck restraints, but also for seat belts. 

A Part of the Whole
The head and neck restraint is only a part of the whole.  A complete driver safety system doesn’t only focus on the seat, the seat belts, the head and neck restraint or any other compenent of the safety system—it encompasses all of the components working together.  One benefit of the extensive laboratory testing that Ashline conducts is the opportunity to evaluate how all of these components operate in symphony with one another to provide the best results.  In a future article we will discuss advances in seat construction that strengthen the effectiveness of the entire driver safety system.

For additional reading on head and neck restraints and to review the results of Ashline’s laboratory testing, visit www.hutchensdevice.com.