Hockey Science

By day, I’m not a hockey player or coach, I’m a mechanical engineer. Some people assume I got my engineering degree because I’m super smart. Honestly, I’m not. I made sacrifices and spent a lot of late nights studying and doing homework. Engineering involves a lot of math and physics, but engineering is mostly just a way of thinking. I call it "Engineering Common Sense".

When I explain a drill or a concept, I often get quite technical. This is because I usually spend some time asking myself “why does this work?” or “why do it this way?” It interests me, and I like to think that in this Discover Channel time, it might interest others. I like to know the science behind what we do on the ice; whether it has to do with why skates glide or how a slap shot works. I also think about equipment and why some designer or engineer created a particular piece of equipment a certain way. Was it for protection, weight savings, or is it purely for looks?

The basic components of a ‘hockey equipment set’ have been around for over 100 years. Shoulder pads, elbow pads, gloves, shin pads, pants, skates and helmets are the staples of hockey. But their appearance, construction and functionality have all dramatically changed over the years.

Science has a lot to do with why our equipment looks the way it does. Chemistry created plastics and other lightweight materials and made them stronger than anything before it. Biomechanical engineering gave us equipment that matches our movements and the exact shape of our bodies. And physics helped create equipment that has us moving ourselves and the puck faster than ever.

The next time you put on your gear, take a look at your gear and ask yourself why it looks and feels the way it does. The answers just might make you think about things like a scientist.

Stride

So now that we have seen center of gravity and balance, lets get into our stride. A good stride stems from a good hockey position, meaning knees are bent, not straight.

A good stride starts with your knees bent and a good push. You want this push to be in between straight back and straight out to the side. so somewhere around that 45 degree angle to the rear, or the southwest if you like the orientation of a compass, or 7:30 if you like the clock aspect, whichever you choose.


As you can see, his foot is turned with his toe facing outward, and it is the last thing to leave the ice, his toe that is.

When you push out, fully extend your leg, then finally push off with your toe. This will make your leg completely extended, with that toe point giving you your drive.

As you push off with that foot and bring it back to the recovery position, you want to keep it low, about 2-4 inches from the ice. This will minimize the energy lost while skating, and help you take longer shifts, and not be as tired when you get to the bench because you have been kicking your feet up past your own knee.

This leg drive and recovery is the most important thing when playing. After all, if you can't skate what else are you going to do out on the ice.

Breaking this down, we can see that it is a sequence of events that make up the stride:

1. Start with your feet next to each other, under your shoulders.
2. Turn your foot(left or right, does not matter) and turn it with the toe slightly outwards.
3. Push off with that foot back at that southwest direction as mentioned earlier.
4. when your leg is fully extended, push off with your toe and point it back and in line with your leg.
5. Bringing that foot back about 2-4 inches from the ice to underneath your shoulders, next to your other one.
6. Shift your weight form one foot to the next and do the same steps as before.

A good stride is something that will come with practice, so try to work on these things in practice. you will be rewarded in game situations when you need to beat an opponent to a puck.

Balance

A hockey skate blade is 1/8th of an inch thick. It is only straight for a small percentage of the total blade length and depending on how it’s sharpened, it can be slightly off center.

So my question is: if you can’t stand on one foot when you’re in bare feet, how do you expect to be able to do the same on that thin piece of metal?

It’s all about balance.

In biomechanics, balance is an ability to maintain the center of gravity [remember that term?] of a body within the base of support with minimal postural
sway.

The human body requires several sensory inputs in order to maintain balance. Visually, a balanced person requires references to tell them what their body is doing. To demonstrate this, try balancing on one foot, then close your eyes and try. When your brain is missing the visual references it constantly tries to rebalance its self and it becomes very difficult to stay balanced.

The brain also requires input from the inner ear.

The inner ear is responsible for the sensations of balance and motion. It is made up of fluids and detection cells and sends information to the brain about the attitude, rotation, and linear motion of the head.

(When you spin in circles and get dizzy, it’s because the fluid in your inner ear is still moving even when your body is stopped. All of a sudden, the information that your eyes and your inner ear send to your brain don’t agree, causing the dizzy feeling.)

Skating is a series of one-foot glides. You stride with one foot and glide on the other. Then you recover; putting that stride foot back down. Switch feet and repeat. It’s a controlled movement. Without balance, that recovery step resembles stomping on a bug; the foot crashes back down to the ice, speed is lost and all your weight is now on that foot. You’re forced to transfer your weight again just to take a good stride with the other foot. This is tiring, inefficient, and it looks incredibly awkward. Throw in opposing players trying to knock you off the puck and falling will become a common occurrence.

Balance comes with repetition; the more you get used to balancing yourself on one foot, the easier it gets. Stand on one foot when you’re watching TV, playing Wii, in the kitchen cooking or standing in line at the grocery store. Try bending your knees more. Try hopping in place. Try twisting your body. Lean forward. Purposely unbalance yourself and regain that balance. Toss a ball from your left hand to your right hand or toss the ball back and forth to a friend, all the while maintaining your balance on one foot. Soon, you’ll find that doing things on that 1/8th inch piece of steel gets a little easier.


Work on your balance while stationary, gradually working towards balancing while in motion. Then work at placing your foot down in a controlled motion. Over time, your balance will come and so will your stride.

Center of Gravity

Everything has what is called a Center of Gravity, or Center of Mass. In simple terms, it’s the imaginary point around which something’s weight is perfectly balanced. It’s also the point that gravity acts through, and gravity always acts downward. In people, gravity acts through a point that is close to your belly button; your Center of Gravity.

I’ve enlisted the help of our friend Don to demonstrate what’s really happening. (Thanks Don!) The red dot is his Center of Gravity and the arrow is gravity.

When Don is standing on two feet (Picture #1), his Center of Gravity is between his legs, half the distance between his skates. He is balanced.

When Don stands on only 1 foot (Picture #2), his center of gravity moves. Now that Don has only one skate to stand on, gravity must act straight through his skate blade. In this case, Don’s Center of Gravity is outside of his skate blade. Unless Don adjusts himself, he’ll fall over.

In Picture #3, Don has adjusted his Center of Gravity so that it is directly above his skate. Don is now balanced.

We’ll talk about balance soon.

The Blue Line Rule

OK, so everyone has been on teams that have had trouble clearing the zone and/or breaking in. This rule stems from that scenario. However it does not solve that problem, but does alleviate it just a bit.

The rule is: When you are about five (5) feet from your defensive blue line, dump the puck out of the zone and across the blue line; when breaking into the zone and five (5) feet from the offensive blue line, dump the puck in and go get it.

Now there are some variations to this, and it mostly applies to when you have pressure, more so when in the defensive zone. Use the boards to get the puck out and at least buy some time to re-organize on defense. The boards are a part of the rink for a reason, so lets go ahead and use them. When you get pressure trying to exit the zone, bounce it off the boards and around the opposing team and step around them to retrieve it.


Now when breaking into the zone, this same method applies. If you receive a good amount of pressure trying to get across their blue line, use the boards and dump it in and go get it. This is better than trying to make the cute fancy move at the blue line, that you may or may not be able to do, that usually ends up in a turnover. Even if you do not get the puck back, the other team has to go nearly the whole length of the ice rather than just two thirds of it when the puck gets turned over at the blue line.

Of course there are pros and cons to both of these, but the pros out-weight the cons. When exiting the zone, they will have to wait for everyone to get on-side before re-entering, giving you time to organize again and get set up, or make a change, even if it is a few people. When breaking into the zone, you don't risk a turnover at their blue line. With both, you will have a less likelihood of having your three forwards leaving the zone, turn the puck over, and have a 3-on-2 going back at your end.

So remember, five (5) feet, and get the puck across whichever blue line you are at. It will save you in some tough spots.

The Heart of Hockey

Hockey players are portrayed in the media as being violent and raw. The only time mainstream America hears about hockey is when someone does something aweful on the ice. It's quite unfair.
This story about the Chicago Blackhawks is one of hundreds of stories that arean't usually told but need to be.

"I've played for different teams in juniors and the pros," said the 26-year-old Sharp, from the Ontario hockey hotbed of Thunder Bay. "And you walk into every locker room and you become brothers. Maybe it's rare in pro sports, but it's not rare in hockey, I don't think. We're all in this together. It goes back to growing up in hockey. My older brother played, I played, and my parents made huge sacrifices to drive us everywhere we had to go. Everyone in this game knows how much family means."

I say it has nothing to do with being from Canada and everything to do with hockey. And with shaking your opponents' hands after you've battled them for 3 periods.

The Face Rule

I tend to develop 'rules' based on things I see out on the ice. Many of these rules build my hockey philosophy and I'm always adding new rules. Some rules are more important than others. I played in an adult-league game last night and something I saw supported one of those rules.

The rule is: If you insist on wearing only a half shield or no shield to protect your face and you flinch and cover your face every time the puck leaves the ice in your general vicinity, you should be wearing a full cage.

Half shields look cool, especially with the variety of tints and colors they now come in. But if you're wearing anything less than a full shield because it looks cool, you've missed the point.

Steve and I coach in half shields and Steve still plays in one. We used to coach in baseball caps! I switched back to a full cage after 5 stitches to the chin and I know Steve has been bloodied on at least one occasion. But in all the games we've played together, I've never seen Steve flinch because of a puck or a stick coming too close (and I'm pretty sure I never did). We still block shots and go into the corners with partial protection because we've learned how to tuck our chins and avoid damage.

This recent post by Third Man In further supports my theory (Warning: the picture is pretty ugly...no blood, but still bad).

Wear what you want to wear but if you're afraid of getting hurt, wear more protection.

Yes, we have ice in Maryland

We’re hockey coaches. We’re also talkers. We think it’s important to not only explain a drill but why it’s important and the concepts behind it. We also somehow manage talk about physics, psychology, anatomy and physiology. We talk about pro players and teams and why we like or dislike what they do.

In case you couldn’t tell, we sometimes get long-winded.

We’re also from Maryland, born and raised. We’re very passionate about the game we coach because those who taught us were equally as passionate. As hockey players in a non-hockey state, we feel it’s our responsibility to help the game grow and thrive.

The goal of this space is to talk about hockey at a level that practice time simply doesn’t allow. We’ll explain and demonstrate drills and concepts. We’ll talk about physics, psychology, anatomy and physiology. We’ll talk about our philosophies of the game. We’ll talk about the pros and our favorite players. We’ll probably even tell some stories.

Yes, there is ice in Maryland. And since there’s ice, we may as well play hockey.