McGill University in Montreal, Canada has been the home to cutting edge hockey research for the past few decades. This research being conducted by the Ice Hockey Research Group (IHRG), led by Dr. David Pearsall, has been asking some very important hockey-related questions over the years. These questions have led to innovative testing methods and insightful findings that have helped in part companies design and manufacture their gear. Apex Skating was fortunate enough to sit down with Dr. Pearsall and be able to share some insights into the IHRG’s work.
Thanks for taking the time out of your day to meet with us, Dr. Pearsall. Do you mind providing a background about your path through education?
Absolutely. I did my undergrad at Queen’s University where I started in Life Sciences and then switched over to Physical Education. That led into a Master’s degree at Queen’s in Biomechanics and Ph.D. in Anatomy and Cell Biology.
And how did that lead you to become the head of the IHRG here at McGill?
Before I arrived at McGill, there was already a long history of field-testing by athletes, coaches and researchers at McGill in collaboration with Montréal hockey companies. When I arrived in 1995, given my biomechanics background I was invited to join their group. As the other professors in the group moved on, I inherited a lead researcher role for the IHRG. We’ve been fortunate to continue to receive matched financial support from the National Science and Engineering Research Council (NSERC).
How involved are the equipment companies in the research? How much of their process do they outsource to you?
They are excellent in engineering design, state-of-the-art manufacturing, sophisticated field-testing and sales. We collaborate by offering our expertise in human (sport) factors and ergonomics assessment. That is, we offer quantitative mechanical and physiological measures of how athletes use their skates, stick and protective equipment. The thrust of our research has been to unpack it and say “well, how do people generate skating locomotion?” or “how do they shoot the fastest?” As a researcher, it is satisfying to collaborate with the skilled workers inside the ice hockey dream factory.
Yes, that would be very satisfying! So, what are some projects that you’re currently working on?
Our projects are built around the three main hockey skill/product categories: skating/skates, shots/sticks, checking/protective equipment. For example, some of our current studies include: body 3D kinematics, force generation, and muscle phasic activity of skating skills including both female and male players. Another is body 3D kinematics of slap and wrist shots (static in the lab vs skating on ice, high vs low caliber players, different stick stiffness). Finally, we also work on helmet impact testing and brain response modeling with respect to concussion protection.
And what are some of the results you’ve observed in these studies?
For one example, we’ve completed a series of 3D body kinematics studies of highly skilled male and female skaters to better understand their skating technique. The skaters were comparable in lower body flexibility and strength (in relation to body height and weight); however, skating push off (knee extension) mechanics differed. In particular, females tended to show more delay (or pause) after initial blade-to-ice contact, resulting in less net forward impulse per stride than males. This begs the question of why does this occur? It could be related to different training exposures or could it also be a compensation to avoid a knee valgus (inward “drop”) posture more prominent in females that is also implicated in knee injuries. More investigation is needed.
Is this something that coaching could change and do you see a use for a youth injury prevention training program?
This would definitely be the logical next step. For example, this has been done in soccer youth injury prevention training program called FIFA 11+ that has had promising results. I absolutely see a future where hockey should create a similar program to avoid non-contact injuries at the hip (e.g. impingement) and knee (e.g. ligament strain). Cross training too, is important for young athletes to avoid over-specialization and burn out.
You’ve mentioned the importance of kinematics in your studies. Can you talk about the different types of technology you use in your research?
Absolutely. We use specialized infrared cameras that pickup reflective markers placed on the skater. This allows us to create a 3D model of their specific body movement. The challenges: we need lots of cameras to cover the skating area, and the electronic cameras and computers do not like wet, cold, and fog from the ice. For these reasons, we are exploring the use of wearable inertial measurement units (IMUs) that track the body segment movements and accelerations. IMUs offer much greater portability and allow us to test anywhere with a relatively simple set up procedure. For force measurements, we have glued strain gauges onto the Tuuk skate blade holder to get vertical and side-to-side skating forces while skating. We see from this how body strength and technique affect skating power. Finally, muscle recruitment and coordination functions have been evaluated using non-invasive surface electromyography sensors.
We’ve discussed a few ongoing projects, but do you have an all-time favourite study?
Yes, I would have to say our universal pressure mapping sensor for the foot and ankle. It gave a lot of great insight about how much we really depend upon the boot itself. For example, these measures indicate that as much as 30% of your skating propulsion can be generated by the ankle-skate interaction in addition to the push-off from the bottom of your feet. We had no idea of this before the project. Many times exploratory studies like this provide new insights of how we actually use these tools (skates) to create movement.
You touched on this earlier but you’ve published some very nice papers comparing high and low caliber players. Can you talk a bit about the findings of these studies and what the major differences are?
Our low caliber participants where recruited from recreational level leagues whereas our high caliber players were from competitive University or Jr. A levels. Skaters were matched for strength, yet in skate start trials, high caliber players achieved faster sprints in large part due to their high body run-to-glide technique than the low caliber. Similar differences were also seen in males and females. In summary, both forward AND vertical acceleration in the start are critical in the first three strides. Another interesting comparison of high vs low caliber are our slap shot studies. For example, using high-speed video to track stick bend in relation to direct measures of puck acceleration. We found that the high caliber shooters were able to maintain longer stick to puck contact (30 millisecond) than low caliber shooters (~20 millisecond) thereby high caliber shooters through strength and timing provided greater puck impulse that in turn lead to greater puck shot velocity.
If you were coaching young hockey players today, what is some advice that you’d give them based on your research?
Take advantage of the technologies that are available that can provide valuable feedback to individual players (and coaches) on physical fitness, skill proficiency, injury prevention, as well as real-time tracking of multiple player attack and defensive strategies. Though be cautious of some products claims. GoPros, iPads, and your phone cameras are easy to use and can provide immediate visual feedback to the players that is easy to understand. It’s profoundly powerful to be able to see yourself and identify areas that need improvement. These, of course, don’t replace fundamental on-ice training drills and development but if used wisely, they can really make your training much more effective.
Where can people find more of your work?
Check out our web page at www.mcgill.ca/ihrg/ and our twitter feed @McGillIHRG. Here we have links to all of our students’ thesis reports and publications, as well as examples of the technologies we are currently using.
Fantastic. Thanks very much for your time Dr. Pearsall – we really appreciate it.