The science of slapshots and skating
March 26, 2007
VAIL ” For any hockey player, a slapshot is a great way to score a goal.
For Mike Torry, it’s an opportunity to prevent injuries.
“We know in adult hockey players, they get a lot of hip labral tears,” said Torry, the director of the Biomechanics Research Laboratory at the Steadman Hawkins Research Foundation. “We’re trying to find out why they get those type of injuries at the elite level. … If we can figure it out, then we can change the way they do thinking at a youth level to prevent them.”
Torry doesn’t just analyze slapshots ” he also takes a look at skating movements like starts and stops. While the concept of studying athletic movements in relation to injuries has been around for a while, Tory’s lab is taking a bold new approach.
From the second you step into the lab, you know something very scientific takes place. There are seven $17,000 infrared cameras on the walls. And Torry gives a polite warning not to touch the walls.
“These cameras are so sensitive that if you vibrate (the walls), it throws off all of our calibration,” Torry said. “The accuracy by which we measure things is in
A giant 5,000-pound skating treadmill touches the front wall. On the left wall there are several computers and television screens. And then there’s the mini hockey rink.
In lieu of ice, the lab uses an acrylic material somewhat similar to a cutting board, specifically made for skating on. The 12-by-28-foot surface is divided into 4-by-4-foot sections that seamlessly fit together. Each section has about 1⁄4 inch of acrylic on the top, layered with 1⁄4 inch of wood beneath, and has acrylic on the bottom.
Two weeks ago, before Tory’s intern, Ted O’Leary, went for a skate, he sprayed some silicone on the surface.
“It feels much more natural than I thought it would,” said O’Leary, who played NCAA Division I hockey at the University of Denver. “You can stop, turn backwards, do crossovers.”
And of course shoot.
But the most intricate part of the entire setup, and the piece that sets it apart from all other operations is a force plate beneath a section of one acrylic square.
“A lot of Canadian Universities have looked at maybe the performance of this ” how people rotate (when they shoot) ” but they don’t have a force plate in the ice.”
The plate, according to Torry, “is so sensitive, it would fluctuate with your heartbeat.”
O’Leary took a few slapshots and then did some stops and starts.
“The force plate give three important forces ” it tells how Ted interacts with the ice, how the ice pushes back on Ted, and therefore Ted propels himself forward. It’s physics.”
When Torry tests players, he sets up about 30 globes on the body of a skater, which are recorded by the infrared cameras and fed to a computer. That, in conjunction with the force plate, paints a picture of how the body works during the movements.
“We can tell how a knee is rotating … what muscles are causing it,” Torry said. “If we understand that, we can say, ‘Here’s where there’s a deficiency in terms of muscles, what muscles you need to build up to prevent those injuries or why the body is wearing down after 1,000 hits on a puck.
“We can look at what degree are (the) feet when you hit a slapshot, and we can look at different training techniques, like should you turn this way or that way to get more power.”
The idea for the lab came up about two years ago from Dr. Marc Philipon, one of the top hip surgeons who treats a lot of professional hockey players.
“He’s always asked us to do hockey, but of course, there’s the matter of how do we do hockey without ice?” Torry said. “So it took us another year to figure out how to do all the stuff.”
Torry, who has a doctorate in biomedical engineering and an undergraduate degree in engineering, said the biggest surprise was how long it took to lay down the fake ice surface.
“We thought it would take a week, but it took us two months … making sure it doesn’t shift, putting the force plate in the middle,” he said. “We had to make sure there was no reflection from the cameras on the ice.”
The treadmill, which will soon be taken out of the lab, allowing for more ice space, provided Torry the chance to study how skaters move in full stride.
“In our setup, we can’t get (skaters) full-speed, full-stride and mid-sprint, which is a pretty important piece,” Torry said, noting that here is no force plate on the treadmill. “We can still measure with the cameras to get the stride width and length, but we can’t get forces.”
With the force plate in the ice, Torry can look at lower-body mechanics, and he wants to study what goes on from the waist up.
“A lot of hockey injuries are upper body. The thing with hockey is there’s a lot of collision,” Torry said. “On March 30, we’re going to have a company install boards in the back, and we’re going to put this same type of (plate) into the wall.”
As they are heading into uncharted waters, Torry admits that they still have to figure some things out on the fly.
“We don’t know the answer. We don’t know the road we’re going to go down,” he said. “We’re still learning how to make the ice better and faster and make the plate more comfortable for (kids).”
In addition to testing top-level hockey players, Torry hopes to get a full range of age and skill level.
“We (look at) different skill levels, not necessarily to say what’s wrong but to compare what is happening,” Torry said.
One of the main goals, in addition to preventing injuries, is to teach younger kids how to play properly, from a scientific approach.
“It’s evidence-based coaching,” Torry said. “What you’re seeing a lot more across the U.S. is a lot of youth injuries because coaches are at the volunteer level. And you’re seeing labs like ours providing information to recreation centers. It’s a trickle-down grass-roots effort.
“Yes, we’re seeing NHL and NCAA players, but the goal is to take it to that grass-roots effort.”
O’Leary, who has played and been coached at a high level, thinks their research will
yield some interesting results.
“A lot of coaching techniques started one day, and it just made sense. If you have a 90-degree knee bend, you’ll get power ” is that the truth? Nobody knows because nobody has quantified it,” he said. “Some of the things like that, we’ll be able to see. … Hopefully we can come up with some numbers to back that up, or we can debunk some myths that are completely wrong.”