The skill "pressure"

Pressure is vertical movement, long leg/short leg for example is managing pressure on each ski.  Extension and Flexion movements are movements that pressure reduce the pressure on the skis.   For example when you go over a rise and you flex your legs to absorb it, and then extend them on the other side to keep contact with the snow, you are managing pressure.

 

The four basic skills in PSIA are BERP.  Balance,  Edging, Rotary and Pressure.

 

 

SMJ covered the basics above so I'll just toss out a few more details as typically discussed in PSIA.

As a skier turns out of Apex pressure builds against the base of the skis due to the Centrifugal Force aligning more and more with the pull of Gravity. (Skiers may also choose to implement speed-control efforts at that point increasing pressure still more, but that's generally not so much a pressure-management thing as a Rotary thing)

Implementing Pressure-Management skills here might mean...

-a) Flexing both legs at a rate consistent with maintaining a desired amount of pressure under both skis (very 'two-footed') while still preventing so much pressure from building up that the skis wash out.
-b) Flexing both legs - but each at a different rate. The skier might do this to prevent excessive pressure build-up while also increasing (or decreasing) their rate of crossover.
-c) Largely maintaining extension of both legs and allowing the Centripetal Force to push the skier further around the corner thus extending the turn while also converting momentum from being down the slope to being more across the slope.
-d) Moving the skier's upper-body Mass forward or backward in relation to the feet to modify tip vs. tail pressure, thereby changing ski-snow interaction performance of the skis.

Note that while "reducing edge-angles" will also (potentially) reduce Pressure under the skis by increasing turn radius (thus reducing Centrifugal Force) this isn't classified in PSIA-Speak as an application of Pressuring Skills. Rather it's an application of Edging Skills that happens to reduce Pressure as an indirect outcome.

I say indirect because reducing edge-angle wouldn't necessarily reduce Pressure. This might happen if the skier reduced edge-angle progressively while also increasing their speed down the slope. Working out the math for this we might actually find an increase in Centrifugal Force and therefore more pressure underfoot despite the reduction in edge-angle.

.ma

My take, without reading the other 2 posts.

 

Pressure is something we manage, the magnitude of which is a byproduct of the turn we chose to make.  Existing pressure management comes in the form of balance management.  Move the balance point fore, and we move the existing pressure towards the shovel of the ski, somewhat put on the brakes, and sharpen the turn.  Move the balance point aft and the tip engagement lessens, the brakes are released, and up to a point the arc softens.  

 

Any pressure self created, beyond that coming as a result of the turn itself, is fleeting.  

The skill is "pressure control".  SMJ summed it up well.

The skill classification is pressure control. As in movements we use to manage pressure. To add to SMJ's post I would say changes in foot to foot weight bearing would also be part of this classification. So some crossover between the skill classifications exists. An example of this is how angulation focuses more pressure on the outside ski even though it is classified as a tipping maneuver. Tipping also reduces the size of the contact patch thus raising the pressure per square CM even though no additional pressure has been added.

That's why it's hard to define pressure without using the term in the definition. At best we could say the forces involved drive the skis into the snow surface and the snow resists this as much as it can. So the amount of force being applied across the contact patch is what we typically call pressure. So the classification got named pressure control.

Rick,

 

"Any pressure self created, beyond that coming as a result of the turn itself, is fleeting."

What do you mean by this?

 

"...Existing pressure management comes in the form of balance management."

Almost worth expanding on the point/area/zone of pressure and the point/area/zone of balance throughout the turn.

 

Carl,

Did you read an earlier post about the biomechanic of the foot? Very informative.

Sometimes students get confused about pressure, and end up thinking it's something you physically do and create, rather than something that's simply there and you manipulate.  They here a statement like, "put more pressure on your outside ski", and their mind translates the message into, "I need to push down harder on my outside ski".  

 

The fact is, you can't just push on a ski and create a sustained higher level of pressure on it, beyond what the existing turn forces can provide.  Like trying to push down on a bathroom scale to increase the reading, you can only raise the reading for a scant second, then it quickly reverses to a reading less than your actual weight.  That's what I mean when I say it's fleeting.  

 

Sometimes when skiing, a momentary spike in pressure is what you want,, sometimes it's just a result of something else you're trying to do,,, but it is certainly not a strategy to employ through an entire turn.  That's an exercise in futility, because it simply doesn't work.  

 

I've talked to many skiers and students who at one point in their learning journeys were confused by this.  They'd spent a good amount of time trying to push down on their skis to create more pressure.  It was only when they made the mental connection between pressure and balance that understanding finally clicked for them, and they came to abandon the idea of trying to over work their skis.  They were then able to simply relax, and let the more refined skill set of balance carry them to the land of better skiing.  

 

As instructors, we need to make sure that our students make that connection too, and don't end up lost in the misconception.  

Thanks Rick makes perfect sense

The bathroom scale analogy is so full of problems. First and perhaps most important is the idea of standing on the scale in a room. In skiing how often do we do that. Perhaps a better model would be riding motorcycles, bicycles, and skating in all it's forms. In that accelerated perspective short term changes in pressure that occur as a result of our movements are what is called pressure control movements. Can we and do we create short term pressure increases in that model? Yup. Do we at other times absorb pressure on a short term basis? Yup. Are those short term changes important? Absolutely. Everything about skiing is about short term changes.

 

Without short term changing movements nothing is constant.

 

JASP, as a model for the totality of the skiing experience, you're absolutely right, a bathrooms scale doesn't come close to describing it.  However, in the isolated context I used it, to help explain the simple concept that you can't self produce sustained higher levels of pressure than that which the turn itself is producing, it works perfectly.  The important message it's meant to help get across is that you don't pressure a ski by pushing on it.  Bad, bad, bad!  You simply balance on its edge and direct the forces that already exist to it.  I spoke briefly about that in my first post, when describing the example of fore/aft pressure management.  I liked that you later added the lateral component.  

 

I view the secondary flexion/extension movements one does to manage pressure while negotiating undulating terrain while turning as a very important but separate topic.  That is done, while simultaneously managing the balance point, and thereby desired location of the pressure.  

 

I also consider the pressure changes that happen through the bottom of a turn as nothing more than a part of the release process, and a separate issue too.  Pressure is ever changing, throughout the entire course of a turn, as we change edge angle and/or steering power.  Those pressure changes are, in most cases, simply a byproduct of shaping the turn in the fashion we desire.  It's generally not a result of a desire to produce a specific magnitude of pressure.  We simple deal with the forces we're dealt, as we continue on through the process of creating the turn we want.  We manage those forces as we need to, to best produce the end product we desire.  

 

 

 

 

I disagree. A skier can most certainly 'pressure' a ski by pushing on it for practical applications!

For instance it may be beneficial to flex through transition and deliberately (somewhat forcefully) extend just as the skis are tipped onto their new edges. This manually pressures the skis far more than the mere "forces we're dealt" at that moment can possibly achieve. Even though this extra pressure generation from extension is fleeting, we only need it for brief moment before Centripetal Force takes over and maintains pressure on the skis for us. This example requires a good deal of 'Pressuring' Skill as modified by Timing, Intensity and Duration in its application.

Simply put, deliberately pressuring a ski ("pushing on it") has a host of practical applications. Both Gravity and Accelerations provide pressure. While a skier can't manage gravity we can both manage and manufacture Accelerations.

.ma

Adding pressure to my ski feels a lot like not collapsing onto it.

 

On the other hand,  freeing ones self of all pressure on one or both skis can be a feeling sublime!

 

"Don't tell me about this stuff,  I want to DO IT  myself!"  ;-)

Exactly.  The turn itself creates the forces, we simply resist allowing them to collapse us.  Our resistance is what generates the sustained ski to snow pressure. 

 

The sharper we turn, and the faster we go, (and the more we eat ), the more the forces seek to drive us into the snow.   

A skier weighs what he or she weighs.  The amount of pressure they feel is dictated by the speed and shape of the turn.  What the skier does will dictate the speed and shape of the turn and the result will be the pressure the skier feels.

 

“I” can’t change pressure except for those brief moments prior to un-weighting (i.e. pushing off to jump).  What I can do is manage the location of the pressure.  I do this by shifting my weight from ski to ski, extending or flexing my legs, changing my fore/aft balance and the like.  I might accept more pressure on one ski, or direct it from the back to the front, but I didn’t increase the pressure.  I merely move it around.  I can also allow more pressure to increase but I didn’t increase the pressure.

 

Pressure will increase the faster I go but for the most part all I’m doing is becoming an enabler of pressure to build and embracing it.  “I” did not increase the pressure but I did allow it to happen. 

 

When I’m making a right carved turn, the forces pressure me to be on the left side of my skis.  I resist that pressure by changing my body position and using that 63mm under foot to brace myself against.  Actually, it’s probably closer to only 20mm of the ski in contact with the snow.  I feel the pressure increase but I didn’t cause it; I allowed it.  It’s more that I sought it out and decided to share a ride with it.  We both have to be there; the pressure doesn’t exist without me turning and I can’t turn without the pressure (forces) acting against me.  If I want more pressure, I make changes with my body position in hopes of going faster and if I don it correctly, more pressure will show up.

 

If in a turn I’m equally pressured on both skis, then for whatever reason, I lift a ski completely off the snow, the pressure felt on that ski is gone from that ski and the amount of pressure felt on the ski that stayed on the snow increased by the same amount, but the total amount of pressure did not.  The only way to increase the pressure for more than a fleeting moment is to have someone toss you something heavy.

L&AirC, good post.  

One of the ski instructors on my mountain, a good skier, swears by pressuring the outside ski in the last part of the turn, by essentially making a skating step without the step.  My question is when is this a good technique, assuming it is. Thanks.

 

Tom

Carl R,

May I suggest you buy, "Ultimate Skiing" by Ron LeMaster. You will get the visual and "intellectual" answers to your question!

Respectfully,
SG

 

 Whenever you want to go faster...and you can safely handle doing in the conditions/terrain you are on.

 

However, you aren't pressuring per se as much as you are redirecting the pressure while skating.  I think of pressure as a force that is opposing another force.  In this case you are moving your outside ski in the direction it is going.  You might shift more weight to it in the process, but "I" don't think you are actually pressuring it anymore than you would normally be.

 

I'm not 100% sure this actually makes you go faster or it just makes you feel like you go faster.  I do like doing it.

 

Ken

 

Flawed Fisics ..

 

The minute I read that I got the image of cracking the whip.  Or how the one wing of a plane is going faster as evidenced by the vapor trail of one wing but not the other when you crack it over in a turn.

 

So, the minute you decrease the radius by pressure and or edging are you going faster till the uphill movement and gravity bring you back down?

 

Two facets?  One ski is a different speed than the other and overall momentary speed.

 

Not thought through but the visual popped in.  Worse, somewhere or sometime that will be asked in a class of beginners.  The kid will be struggling with the "Intro To" course and strongly resemble ...

Can you explain how skaters can skate in a circle and pick up speed but skiers can't?

 

The airplane analogy doesn't fit because the wings don't move independently.

 

In my post I never said increase pressure or edging.  I said to skate the outside leg forward in the direction of travel.  Edging shouldn't be changed.

 

My thought is that one ski picks up speed and the inside one comes along for the ride.  In the next turn the favor is returned.

 

Do you believe that you can skate on skis without taking your skis off the ground?  If so, why won't this work?

 

I'm not saying I'm correct.  I'm saying you haven't convinced that I'm not yet.

 

 

The skill classification is not offered in such a narrow way Rick. Ultimately that's the question here from what I can tell. That wider world is the world of the PSIA skills classification. So while I agree that short term changes are all we can do, it's important to understand that Gravity is the only constant in a ski turn. Even that force acts differently at different points in a turn. Since there are no constants the whole issue of needing one seems a bit moot.

JASP, I not really sure where we're squarely at odds.  I suspect at the root of our belief system we're not.  Actually, I'd bet a bucket full of money on it.

There is a fairly large thread devoted to that move, discussion started by simplyfast.

 

Other things to be considered while turning.....
 

 

I started using that in slush last week to keep the pressure on the outside ski and prevent it from bogging down. 

It's not a huge move -it's really moving pressure from ball of foot to heel.

 

Rick we're not at odds at all. Even on the bathroom scale Hopping involves brief pressure increases and those increases are created by muscle power. So while our weight doesn't change we're creating an upward acceleration by increasing the pressure between us and the ground. In turn, the ground responds by either sheering, or pushing back and we become airborne.

On snow, leapers are an alternate cert maneuver that feature a hop.

Another situation is Extending on the back of a bump to create contact and pressure, it's another example of using muscle power to create pressure that would not otherwise exist.

PSIA's pressure control classification includes these but from what I can tell your pressure classification excludes it. Not sure what you would call them but I hope you will share that information.

Edited by justanotherskipro - 4/26/11 at 10:38am

I find it interesting, JASP, how different schools of thought breakdown the same whole into different pieces.  I worked construction for a while with a good friend of mine.  Sometimes he and I would approach the building process with slightly different methodologies, but in the end the final product would be the same.  For good ski carpenters, it's much the same.

 

I use a number of "leaper" type drills, and the skill area I assign them to varies, because I use them in various ways, to achieve various things.  I may use them to develop flexion/extension skills.  I may use them to work on balance skills.  I even have versions I use (counter hops being one) to work on rotary skills.  

 

Many of the drills I use are multifunctional like that.  I can use them to work on various things.  Over the years I've developed many of my own drills, and I see it kind of like pharmaceutical development. Drug's are developed to address an existing problem, but often after the drug hits the market new uses are found for it.  Same goes with drills.  Drills are just tools, devised to help students work on specific technical issues.  Often those same drills can then be pirated, and perhaps slightly modified, to be used for other skill issues.

 

For the most part, I don't do a lot of work focusing on what I would classify as pressure management, because I see most pressure changes as a byproduct of other things we do to achieve goals outside of pressure change itself.  Take the simple leaper exercise.  The goal is to, well, leap.  Flexion/extension is the primary tool we use to make  it happen, and a pressure spike is just a byproduct that occurs as a result.   The focus I use is for the student to see how high they can get off the snow,  not to see how much pressure the can exert.  Same with sucking up a bump with flexion/extension.  The outcome is a more consistent level of pressure, but the true goal was to avoid getting launched, and keep connected to the snow with the CM continuing to move forward on its intended course.  

 

I do use pressure a lot, as a focal point when working on balance state management, and transition skills.  It's an excellent sensory awareness tool for helping people learn proper execution, and too self monitor and coach themselves.  

 

Just this old woodworkers way of wielding his hammer and saw.  

 

Our focus and objectives are congruent in those activities, even though we don't always classify things the same way.

Ski Well my FRiend,

JASP