Impact by design
By Jennifer Sowa
Sean Maw, adjunct prof of kinesiology, Mount Royal College, and Cliff Johnston, Mechanical and Manufacturing Engineering, U of C, with the Impactor nestled against a crash pad.
In any high-performance sport, there’s always the chance of injuries. In a world where athletes strive to be the best, the fastest and the strongest, it’s no surprise that safety has become a top priority. Engineers often get called in to help minimize the risk for athletes.
/ Photo: Ken Bendiktsen
Now there’s a new design for crash pads for the sport of speed skating. The pads have already been used in the World Cup and will make their Olympic debut at the Vancouver Games in 2010.
Clifton Johnston, a mechanical engineering professor at the Schulich School of Engineering within the U of C and Sean Maw, an engineering instructor at Mount Royal College with a background in systems design, spent the past seven years researching and developing a system to help reduce injuries.
“If you crash into the side of the rink, you don’t want padding that’s going to fling you back into the path of oncoming skaters,” explains Johnston. “Those skate blades are razor sharp.”
Horror stories abound of speed skaters falling and getting slashed by 16- to 18-inch skate blades. Then there’s the danger of crashing into the boards at high speeds. According to a study published in The American Journal of Sports Medicine, a key factor in the severity of many injuries is the type and quality of protective matting covering the rink boards.
The solution is a material that seems pretty ordinary and generally unexciting to most people: foam. In fact, there are hundreds of different kinds, and the researchers have put in long hours experimenting with them.
“Combinations of different kinds of foam give you different responses,” says Johnston. “Once we know the application for it—in this case, to minimize injuries to skaters—we have to find the right combination of material. You’re going to need multiple combinations. It’s a fairly complicated process.”
The Impactor, at 54 kilograms, simulates the body weight of a speed skater crashing into the pads.
The main tool for all this research is the Impactor: a six-metre-tall contraption of pulleys, ropes and cables. Its long arm swings a 54-kilogram steel barrel that thuds into pads mounted on the wall. A sensor called an accelerometer measures the force of the impact and the bounce-back effect. This data gets fed into a computer for analysis.
“We’re trying to minimize the amount of bounce-back and the amount of peak deceleration skaters experience when they hit the pads,” says Johnston.
Usually, that involves several layers of foam: a soft layer on the outside, a harder layer inside, and a layer at the back to absorb the force of the impact.
Because of their research, Johnston and Maw were called upon to design the pads for the 2010 Olympics. They were also hired to retro-fit a venue that previously hosted the Olympics: the Utah Olympic Oval. Whatever they’ve done appears to be doing the job.
“In 2008, the Oval in Salt Lake City had its own crash-pad system and 10 people were taken to the hospital during the World Cup. Now they have our system in place and this year, everyone was happy, everyone was safe,” says Sean Maw, adding that his biggest reward is seeing skaters get up from a fall unhurt.
“In Vancouver this year, a skater went head-first into the pads. It was a fall that had the potential to cause very serious injury. He got up and skated away and he’s still vying for the national team today. Things could have been a lot different.”
Clifton Johnston says he’s looking forward to seeing his contribution to the Olympics on big screens everywhere during the speed skating events.
“If no one gets seriously hurt, then we’ll walk away knowing we did a good job.”
