Sports tech: Ice hockey kit and players get high-tech scrutiny at McGill
Image credit: getty images, McGill University Ice Hockey Research Group
Ice hockey gear doesn’t simply need to assist players in their quest to be the best. It has to survive one of the most rigorous stress tests in sport – the ice hockey clash.
Ice hockey players move around the 61x26m pitch at up to 30mph for 60 minutes. They twist and turn to evade opponents, catch up with players or find space so a teammate can pass. At speed, they have to steady themselves to strike the puck, pass it, block shots, and avoid colliding with other players or the hoardings. Sometimes they may even charge across the rink to fight with the opposition. It’s evident then that skates, sticks, helmets and all the associated gear need not only to enhance movement and skill, but to ensure safety at the same time.
Some variant of ice hockey has been played in Canada since the early 19th century. Yet it wasn’t until 1872 that the first organised indoor game took place. Students from McGill University in Montreal were involved in that game, and two years later the university set up the first ice hockey club. In 1879, McGill students and local journalist James Creighton, who played for the team, devised the first official ice hockey rules.
These days, McGill has its very own Ice Hockey Research Group – experts who evaluate the ergonomic and mechanical function of skates, sticks and protective equipment. They run a graduate biomechanics programme focused on human performance measures of the equipment. The work is funded by equipment manufacturer Bauer Hockey and the Natural Sciences and Engineering Research Council of Canada.
“We investigate the unique type of locomotion that hockey players use on the ice and the risk factors involved,” explains the group’s director, David Pearsall, an expert in biomechanics and anatomy.
Skates are supposed to provide players with enough grip to move speedily, but not so quickly that the player can’t stop or change direction without being hurt.
Pearsall explains that the side-to-side skating motion can cause muscle tears, particularly in the abductor muscles on the inside of the leg. To help avoid this, the McGill experts have established at what point a muscle is active during a skating stride, at what speed it is stretched, and the injury risk factors when athletes skate at variable speeds.
The researchers use piezoresistive sensors to map various anatomical features of the body (such as the points of a foot while inside an ice skate), and an electrogoniometer to measure joint angles in two dimensions. At the ankle, for example, the researchers can simultaneously measure flexion, inversion and eversion using a single sensor. “We can help prevent injuries if we can identify when this muscle is active and stretched at the same time,” Pearsall says.
Bauer Hockey made the first ice hockey skate with the blade permanently fixed to the shoe way back in the early 1930s. Before that, ice hockey skates were tied to the ankle of a boot with leather straps.
Until recently, ice hockey skates tended to be stiff to provide ankle stability but, according to Pearsall, this is at the expense of mobility and skating power.
“A stiff skate is good for forward-to-back motion but not when you move sideways,” he says. “We’re looking at ways of freeing up the foot and the whole limb, so that [the skating motion] can work more like running.”
To this end, the McGill researchers use a strain gauge system on the skate blade holder (called the ‘tuuk’) to work out the vertical and medio-lateral forces applied on the skating surface both when a player stands on the skate, when the skate compresses and when the player skates. From this, they can calculate the force when a player skates, the deformation when they shoot and predict the force values.
The McGill experts also use the strain gauge system to test how effectively ice hockey sticks transmit energy to the puck when players shoot, pass or clear it. In addition they have investigated how much the grilles and visors attached to helmets affect vision. Using photogrammetry it has been possible to create 3D models that provide data so manufacturers can design more comfortable and better-fitting helmets.
They’re currently looking at ways to make their knowledge accessible to players and coaches through handheld technology, although the group could be searching for new sponsors soon, as Bauer Hockey recently filed for bankruptcy in the USA and Canada.
“Hopefully the new owners, whoever they are, will see the need to continue the work we’re doing,” Pearsall says.
He adds that although players might intuitively know when they’re performing well, or whether a piece of equipment feels right, analysis performed at McGill checks whether these instincts are correct. “What we do informs coaching and performance analysis,” Pearsall says. “We concentrate on how people actually do what they do on the ice.”
One of the most important movements in ice hockey is the ‘push off’. This is where a player pushes off the edge of the skate to gain speed. The low friction of the skate blade enables a player to glide easily over the ice. The make-up of the ice is what allows a player to dig in with their skate in order to turn, speed up or stop.
“The optimal push-off angle depends on speed and acceleration,” Pearsall says. “If you put sensors on skates, you can measure force and power. Players can see the actual force they are using and how they might change their technique to gain more power.”
That’s player movement covered. And skills, sticks, skates, helmets and visors. All that’s needed now is a sensor to predict why, during matches, the red mist occasionally descends and players stop playing ice hockey and, instead, get themselves involved in punch-ups with the opposition.
Bauer Hockey’s OD1N protective gear is mapped to each player’s body with a 3D scanning tool. Bauer can then build each shoulder pad, elbow pad and shin pad to precise measurements. High-tech foam reinforces specific areas throughout the body suit, such as the small of the back or the neck. This means foam and plastic can be removed from the shoulder, elbow and shin pads, reducing the player’s weight, which means the player can move faster across the ice.
Statistics: Hungry for evidence
Corsica is a database that contains a range of National Hockey League (NHL) statistics, match results, player stats and analysis of events that occur during games. From this, fans can get empirical evidence to resolve disputes over questions like who a team’s best passer is, how much a certain player contributes to their team’s success and which players are not performing up to the required level. Coaches could use these sorts of statistics when looking for the best way of using a particular player’s talents.
During the NHL-sanctioned World Cup of Hockey earlier this year, the NHL worked with sports technology innovator Sportvision to embed tracking devices inside pucks and on the backs of players’ jerseys. This helped broadcasters capture movements of the puck and players. Using infrared cameras, placed all around the pitch, the tracking chips generated data relating to puck and player speed, distance travelled, puck trajectory, shots, shot distance, shot direction and possession statistics.
Software training aids
Several Champions Hockey League clubs and US Hockey’s National Team Development Program are using IntelliGym, software used by the US and the Israeli air forces to train fighter pilots. The program helps to hone anticipation and spatial awareness, cognitive functions players need on the ice rink, which are very similar to what fighter pilots use during aerial combat. Most ice hockey injuries are caused when players collide unexpectedly. A study of the USA National Team Development Program over five years showed that IntelliGym training reduced head and neck injuries by over 25 per cent.
The NHL’s Washington Capitals use STRIVR’s virtual reality technology to enhance training. They film practice sessions, upload footage, and then players can view this in 3D, with a standard virtual-reality headset. The players get an observer’s view of what they do and what is going on around them which enables them to recognise errors and potential options in play that they wouldn’t see during the actual game.