Head On

University of British Columbia researchers have developed a proof-of-concept sports helmet that can reduce direct impact to the neck by up to 56 percent, according to preliminary tests. Such an invention, they say, would be a boon to the approximately 1,000 people who suffer spinal cord injuries in Canada, annually.

“Existing helmets are not designed to protect the neck and the cervical region of the spine, which happens to be the weakest,” says Peter Cripton, a mechanical engineering assistant professor in UBC’s Faculty of Applied Science, who berthed the project in January 2005 with PhD candidate and co-inventor Tim Nelson.

Dubbed Pro-Neck-Tor, the patent-pending technology employs a movable inner shell that guides the head to tilt slightly forward or backward upon impact. Cripton says the spine is most prone to injury when it’s aligned in a straight column and the head is flexed forward at about 30 degrees. A headfirst impact in this position can load the neck with as much force as the weight of five or more people, resulting in spinal cord injury and permanent paralysis.

“So what we try to do with the helmet is, at the point where the head hits the board or another object, we turn the surface that you’re striking into an angled surface,” says Cripton, who is also director of the UBC Injury Biomechanics Laboratory, with facilities at the Vancouver Coastal Health Research Institute.

The mechanism is as simple as it is effective. A tab attached to the outside of the helmet’s rigid inner shell travels down a set of guideways on the inside surface of its moveable outer shell. On head impact, the tab is guided into one of the guideways, thereby rotating the wearer’s head either forward or backward and allowing the neck to bend rather than compress.

Changing the angle of impact, he explains, helps to dissipate direct loads to the cervical spine when the Pro-Neck-Tor’s mechanism is deployed, which happens only when the “threshold force” is reached and the wearer lands headfirst with a certain speed and angle at impact. Otherwise, it works like existing sports helmets.

With help from surgeons from the UBC Dept. of Orthopedics’ Spine Surgery Division at Vancouver General Hospital, and researchers from the Division of Orthopedic Engineering Research and the International Collaboration on Repair Discoveries (ICORD), Cripton and Nelson have conducted preliminary tests using an in-house-designed mechanical head and neck model.

Results show the Pro-Neck-Tor can reduce both torques and forces to the neck. The forces were reduced by 27 to 56 percent and torques 19 to 72 percent, depending on the angle of the impact.