Basic Considerations in Power Slide Mechanics
In a recent article I presented three basic drills goaltenders encounter at camps and clinics with which to develop edge control for the “down” game, and a few readers expressed interest regarding the actual mechanics of the power slide.
While developing this technique is vital to the modern game, it can be very frustrating for both young and old at the beginning of the learning curve. So let’s look now at several considerations when working on this technique as time and motivation allows.
1. Sharp Blade Edges: Since this technique is performed on the inner edge of the skate, it’s naturally important that your skates are always sharp. It is important to understand however that a greater, or deeper, hollow (e.g. 1/2 versus 3/4) doesn’t guarantee greater success with the push. All professional goaltenders are proficient with power slides but they have individual preferences for skate sharpness, ranging from 3/4 up to 3/8.
2. Blade Height: The issue of blade height and its importance to butterfly goaltending have been well discussed in previous articles at InGoal Magazine. The higher the cowling is off the ice, the better the “attack angle.” This means the cowling can get lower to the ice before causing a slip out, or lost edge, which leads not only to an inept push but potentially to groin injuries.
A higher blade has the additional advantage of not requiring the goaltender to bring the power leg as far in (loading) as they do with a blade of lesser height. In other words, the loading mechanics prior to the actual push are fractionally less time consuming.
This may, however, also be dependent on the leg length of the goaltender. A goalie with short legs may have to bring the force-generating leg further in prior to sufficient loading and will also lose contact between ice and skate blade earlier.
The difference between a standard runner and Step Steel, or Step Steel Extreme, is more than a quarter of an inch. This may not seem like a lot, but it provides favorable loading properties. If less time is required to load the power leg adequately, then time has been saved. This saved time may allow for additional saves being made.
3. Pad Positioning: Whether a goalie prefers to have the pads strapped down below the boot break is an individual preference; however, choosing not to do so (like, for example, Henrik Lundqvist, Danny Taylor and Viktor Fasth) allows the pad to sit further away from the top of the skate. The loose nature of the binding of pad to leg also allows the pad to roll up on its side when its starts to make contact with the ice thereby improving the attack angle.
4. Loading Angle: The angle between the ice and the loading leg has a great deal to do with the success of the push.
If the power leg is brought in too far, the angle between the tibia and the ice becomes ever more perpendicular and hence the tension loaded on the knee is tremendous. Under these circumstances, even in the presence of strong quadriceps, a push can only be initiated if the goalie rises slightly off the ice (as if starting a recovery to their feet) prior to executing the slide. This creates a more favourable angle between femur and tibia at which point leg musculature can become effective in generating force.
This is something small kids commonly due at the beginning of the learning curve. This usually happens because they either overloaded the power leg or because of inadequate leg strength at this age. This is acceptable at the beginning of the learning curve; however, as strength improves you want the lead pad edge to be flush with the ice so no “cheapies” slip in under the pad.
Here is the first video segment from the original article (Importance of Edge control for “Tight Zone” play). You will notice the loading angle is not excessive, and relatively constant, for the demonstrating goaltender:
Two still photos of the same goaltender reveal the loading angle at which this fellow feels comfortable:
For comparison, here is a training clip provided by Kory Cooper of the Mississauga Steelheads while working with goaltender Spencer Martin. The video segment shows game-like application of down movement. The key observation is the lower loading angle for Martin’s power leg compared to the prospect in the original segment. Martin is taller, older and stronger and generates a lot of power even with a loading angle of arguably no more than 30 degrees:
Spencer Martin (featured in the video above) of the Mississauga Steelheads is ranked 5th amongst North American goaltenders by Central Scouting for the upcoming 2013 NHL Draft, and recently won a Gold Medal at the U18 World Championships
This will naturally vary from goaltender to goaltender based on ability and anatomical differences.
5. Blade Contact: Another factor in success is the portion of the blade with which you make the push.
A goaltender may use the toe, the heel or most of the blade to change potential into kinetic energy. Most instructors would probably favour the toe as being most accurate. I prefer the goaltender uses as much of the blade as possible. The author has no scientific data with which to validate his belief; however, it will be explained on the basis of Newtonian physics.
For every action, there is an equal and opposite reactionary force. This is why the loading angle is important. You want tangential force vectors to propel you laterally across the ice. The author believes that the greater amount of force applied to the ice, at a favorable loading angle, the greater likelihood of success. If only the blade toe is employed, all the force is being applied basically on a dime and may place more strain on the knee if the loading angle is excessive. If the blade’s toe doesn’t dig into the ice there is no margin for error and the push is inadequate or lost all together, while a larger portion of the blade in contact with the ice improves balance and stability.
Here is an example of a goaltender favoring the blade toe method:
The heel or latter third of the blade is also an option. I personally found this the easiest manner with which to achieve success, even though the full blade may be better from a balance/stability point of view:
The thing I like about using the entire blade is that force vectors are being applied to all aspects of the blade and hopefully force applied over a greater surface area (albeit as narrow as a skate blade) creates greater balance:
5. Push Distance: Try and keep the length of your push moderate at best. There is no point in bringing your power leg out to the point of near complete knee extension. The objective is to reload while you are moving across the ice. If your pushes are too long, inertia is lost. You want to reload and push again prior to slowing down. Otherwise, you will work harder than required and will waste valuable energy.
With practice you will find out what works best for you. In general, quick repetitive moderate distance pushes are most efficient biomechanical.
When working on your lateral pushes here are a few more things to consider:
1. At the beginning of the learning curve perform your pushes when the ice is smooth after re-surfacing. This makes the process easier since less frictional resistance exists.
2. Initially try performing drill #1 in the first edge control article along the blue-line. Many goalies find themselves moving in a zigzag pattern and not in a straight line. Are you pushing straight back or are you pushing sideways? The blue-line can be used as a reference point to correct your direction of movement as required:
3. Check the quality of your pads as older pads with natural leather versus synthetic material may render the pad a poorer slider in nature.
4. Make certain that you always slide on the edge of the pad and not on the face. This seems logical but many youngsters make this error.
5. Finally, when you get good at the biomechanics of the push/slide, then start working on slides and pivots in the crease near the end of the practice. The ice will be all cut up and full of shavings, which makes the process much more difficult. This increases the need to develop more power and improves stamina. For old-timers, you can do a few reps when the play is at the other end of the ice surface during a game.
This is why I prefer to perform sliding drills near the end of practice when the goalies are tired. Working on slides and pushes on rough ice improves strength and stamina for late in games when conditioning may be the difference between victory and defeat.
I hope the factors considered in this article will be of some benefit to those whose struggle with the mechanics of the lateral power slide or push. I will follow up with additional articles with intermediate and advanced drills for this all important goaltending technique.