or Connect
New Posts  All Forums:Forum Nav:

Fore/Aft Balance

How does for/aft balance change throughout a turn and how do we affectively stay balanced through those changes?

Great question Loki

Caveat - there all always exceptions. I'm not mentioning them all.

In general, it helps to be moving (diagonally) forward at the beginning of the turn. Then as the skis turn more down the hill, they travel faster than the body. At the end of the turn, as the skis go more across the hill, they slow down relative to the body and allow the body to start moving forward to begin the next turn. So, as the skis are pointed more down the hill, weight is shifting backward and as the skis are pointed more across the hill weight is shifting foreward. In general. For efficient skiing.

Racers sometimes let the skis get way ahead of them at the end of their turns so they can pressure the tails to "jet" them even faster. But those that do this successfully have incredibly strong cores to pull themselves back over their skis. In short radius turns, when the body is moving straight down the hill and the skis only spend a miniscule portion of the time going straight down the hill, the fore/aft balance difference is minimal. In moguls, we sometimes shoot the feet ahead to "catch" the next bump and lever against it to slow down.

So how do we stay balanced with our weight shifting all around like that? Technically we don't. The general idea is that our out of balance condition propels us in the directions we want to go. This creates a condition called dynamic balance where we are in balance relative to the desired movements we want to make over time (aka turns).

I'm an old skier learning mono-sitski and just starting to carve.. According to my instructor the key 'thing' I have do right after initiating the turn, is to time the smooth return to mid-balance to weight the tail of the ski to keep the carve going to reduce the wash out. Jetting will come later..maybe

I've started to notice that along with the diagonally forward movement at the beginning, I also sort of raise up my stomach(!!) ..  I think its a bit analogous to stepping up onto the uphill ski like in the old days ...

Weyham,

[I chose "the" to match my website and to avoid confusion with other "Rusty's" - but in threads with no other Rusty's posting, Rusty is just fine]

You have my utmost respect. I've been in a sit ski once. It remains my scariest experience ever on snow. Something about the duct tape around my feet set the tone for the whole experience,

Yes, any over pressured part of a ski will wash out. Many skiers over pressure the tails and wash them out, but it is possible to over pressure the tips. Raising up your stomach sounds like old fashioned up unweighting for turn inititation. I'm not sure why you'd need it, but I'll take your word for it. Although the ability to manipulate weight distribution while in a sit ski may seem limited, my experience was that the required amount of movement was below my threshold of detection. I was told that I was maneuvering, but I felt totally out of control. So I can totally believe that you would need to pressure the tail to finish a carve. I just can't imagine how or how much movement that would be.

Imagine two paths Loki. The path of the body resembles a sine wave down the slope. The path of the skis and feet is longer, rounder and resembles linked half circles that go out to the side further than the sine wave does at the fall line. Both intersect at the transition though. It follows that the longer distance traveled by the feet and skis means they are actually traveling faster than the body over the course of a turn. The coordination and timing of our movements are done within this framework. The two paths (and the different parts of the body) are playing cat and mouse and one may be ahead of the other momentarily but they alway end up at the same place, at the same time, by the end of the turn. At least in theory that how it happens. Some people never get them to that same place by the end of the turn but that's another story that we can sum up by saying we can allow one of the two to lag behind the other through the end of the turn. It's not usually a good thing though since we're not really set up well to start a new turn. Some racer will do that on purpose for one turn, or because of the dynamic nature of that type of skiing they end up in that that position. Overall it isn't really where they, or we want to end every turn.

However during the turns we have a couple of options, we can modify the timing of these two paths a little by projecting our body into the new turn and allowing the feet to catch up by the end of the turn, or we can allow the feet to get ahead of the body and move the body to catch up to the feet. On skis we have a greater range of fore/aft movement available than we have in our street shoes. Allowing us to play cat and mouse over that wider range. Go out and play with this idea and try to feel the cat and mouse game our feet and our body are playing. As you do so change the timing to find out how that feels. At some point you will discover for yourself what works best for you and what doesn't. I alway have fun doing this type of exercise which is called a good turn, bad turn drill. The Mahre brothers are famous for a lot of these drills that they published in their book No Hill Too Fast.

I hope that helps...

Edited by justanotherskipro - 2/11/2009 at 04:27 pm

Edited by justanotherskipro - 2/11/2009 at 04:32 pm

So i understand the basic idea of the path of the COM and the feet.  What I am asking is how does one maintain For/aft balance throughout a turn when the longitudinal balance point on the ski changes as it accelerates and decelerates.  I am looking for a more specific description of for aft balance throughout a turn.

The longitudinal balance point of the ski changing?...I don't think so.

The skis tend to run out from under the body during the turn.  It is necessary to recenter, or maintain center.  The way I prefer to do it is to pull both feet back under me (feels like they're behind me, especially on steeps) when the skis are light on the snow during the turn transition.  The steeper the hill, or the more you need to recenter, pull back more strongly.  I tend to get back on my skis during the turn, so to prevent this I strongly pull the inside foot back all the time, again more strongly on steeps or if I'm tending to get out of center.  Others say to move the body forward, but there's little leverage or strong muscle groups to move the body relative to the feet, and the strong hamstrings are available to move the feet relative to the body.

Or just let the skis go out to the side, guide them around with the legs, and then they come back underneath you as the body took a different path. No need to rinse, just repeat.  The feet certainly are not under the body at all times.

I too have a question about this.  When initiating a turn, I've tried experimenting with different pressure distributions.  I've tried concentrating on the tips--so that I'm leaning forward, and actively trying to drive the front inside edge of my downhill ski into the snow.  That worked kinda--but not so much.  But I found that I got the best results when I leaned back more, and tried to pressure the WHOLE edge--making sure that my tails were pressured too.  I tried to concentrate on distributing my weight over my entire foot--so that my heel and the ball of my foot had equal weight distributed (versus all the weight on the ball).  I tried to concentrate on having my foot flat against the bottom of the boot and pressuring it evenly (of course, keeping pressure on my front shins as well).  My skis carved best when I did this.  What do you guys think?

Mrzinwin, that sounds about right to me. You've experimented and found the sweet spot on your skis. I've found that it depends on the ski.  When carving on groomed/firm snow, some of my skis like a bit more fore pressure to carve cleanly, some a bit more centered.  Soft snow is another matter.

Related to fore-aft pessure management, a common problem many skiers have is the chattering or skipping of the tail at the end of a turn on steeper terrain with hard snow, and this is very often a function of too much forward pressure.  The lack of weight on the back of the ski prevents the edge from holding.  Of course, flexing at the end of the turn is also key to manage chatter.

Quote:
Originally Posted by zkurtb

Mrzinwin, that sounds about right to me. You've experimented and found the sweet spot on your skis. I've found that it depends on the ski.  When carving on groomed/firm snow, some of my skis like a bit more fore pressure to carve cleanly, some a bit more centered.  Soft snow is another matter.

Related to fore-aft pessure management, a common problem many skiers have is the chattering or skipping of the tail at the end of a turn on steeper terrain with hard snow, and this is very often a function of too much forward pressure.  The lack of weight on the back of the ski prevents the edge from holding.  Of course, flexing at the end of the turn is also key to manage chatter.

I've also found that binding position has a big role in this.  When I moved the binding forward, I found I needed to lean back a bit more to get to the sweet spot.  I guess that makes sense.

PSIA has been using BERP  (Balance, Edging, Rotary, Pressure) for a while.

I think they're moving to a new acronym for the younger Instructors.

Fore, Aft, Rotary, Tipping (FART)

As a turn progresses our direction changes and this in turn causes the forces involved to have a different effect. Gravity can pull us into a turn at times yet it will pull us away from a turn at others. Forward momentum might seem more constant but as we traverse across the hill we lose some of that momentum, going uphill we lose all of it, and going downhill we gain it. Add lateral balancing needs from our tipping activities and it should become obvious that balancing isn't about finding one spot and trying to stay there. The dual paths model represents a relationship between the trajectories of the CoM and the BoS (core and the feet). Reducing these trajectories to a frame by frame approximation might help get you in the right vicinity but even then our stance depends on the snow surface, which can be highly inconsistent and constantly changing. Especially in areas like a mogul field.

Does fore / aft balance change in different parts of a turn? Sure! How it changes is a more complex answer though. Any discussion of that needs to include an intended outcome to provide some context. I would also point out that doing all the math might not add as much to your understanding as going out and experimenting with different stance options. I cannot stress enough that the answers lie outside on the hill. Get a coach and go play with this stuff.

Edited by justanotherskipro - 3/24/2009 at 07:44 pm

Quote:
Originally Posted by SoftSnowGuy

The longitudinal balance point of the ski changing?...I don't think so.

The skis tend to run out from under the body during the turn.  It is necessary to recenter, or maintain center.  The way I prefer to do it is to pull both feet back under me (feels like they're behind me, especially on steeps) when the skis are light on the snow during the turn transition.  The steeper the hill, or the more you need to recenter, pull back more strongly.  I tend to get back on my skis during the turn, so to prevent this I strongly pull the inside foot back all the time, again more strongly on steeps or if I'm tending to get out of center.  Others say to move the body forward, but there's little leverage or strong muscle groups to move the body relative to the feet, and the strong hamstrings are available to move the feet relative to the body.

This is is biggest lesson I've learned this year. Pulling the inside ski back under me has transformed my skiing on steeps and bumps, wish I'd come across this trick a long time ago.

Why do you think this helps?  What does it cause you to do?

Loki1, while acceleration/deceleration can have a small influence on the fore/aft balance point, the bigger issues are the execution and the mental/instinctual reactions.

3 things move the balance point fore;  flexing the ankles forward, extending the knees, and flexing forward at the waist.  Articulate those joint in the opposite direction and we move our balance point aft.  Slight tension in the core helps keep us from getting pulled aft by mistake.  That's the simplified execution end of it.

Now the mental side of the equation.  We humans are programmed for survival.  When we feel acceleration, or a steepening of the slope, our natural reaction is to retract away from the speed or the drop.  We move aft.  That natural reaction has to be overcome.  Moving aft actually does the polar opposite of what our innate reaction intends,,, it makes operating the ski harder, and thus increases our chances of buying the farm.  We have to train ourselves to do the opposite of what our bodies naturally want to do.  We need to move toward the danger.  Once we do, we quickly discover how much better our skis perform, and how much more secure we feel because of it.

www.YourSkiCoach.com

Moving forward is easy if our point of reference is moving as well. Like standing on a boat, or in a bus. What gets complex is when we are moving through the environment and constantly changing directions. The platform (skis) is still moving but it is easy to get caught up in the idea that that platform can't be trusted. One we make that leap of faith the balancing is a lot easier.

Moving towards the danger means more mogul training -- every mogul is a transition.

Anytime our skis accelerate rapidly such as when they are turned toward the fall line there will be a tendency for the body to get left behind, relatively speaking. This will leave us in a poor position fore/aft wise to effectivelly utilize our skis for turning. In anticipation of this, expert skiers generally begin an adjustment of fore/aft position as they commence a turn. Whether this is envisioned as a moving  of the body forward, relative to the skis or a movement of the ski backward relatrive to the body may or may not be a matter of perception. As the skis slow as they are turned across the fall line at the conclusion of the turn there will be a tendency for the body to continue to move forward relative  to the skis. This can be utilized in the next turn by allowing this movement to accomplish the fore and aft adjustment described above. The perception of this in the skiing of an accomplished skier is a continuous flowing movement of the upper body. If the intention is not to continue to a new turn then the movement of the upper body relative to the skis must be stopped. This could be done by an edge set in which the body is balanced against the edge  (ie to the inside relative to the ski) or by having allowed the body to get behind in anticipation of the skis sudden deceleration.

This is my take on an answer to the original question for whatt its worth.

If you have the chance go play on some snowblades.

Quote:
Originally Posted by justanotherskipro

If you have the chance go play on some snowblades.

I'll bet they are excellent training for maintaining fore/aft balance, presumably unforgiving.

They do not have enough length for big fore / aft movements. That being said the forces involved align differently during different phases of a turn. So we can't just camp on them either.

Quote:
Originally Posted by justanotherskipro

They do not have enough length for big fore / aft movements. That being said the forces involved align differently during different phases of a turn. So we can't just camp on them either.

My point is that I would think (I've never been on them) that you must have to maintain perfect fore/aft balance throughout the turn or you would fall over.

release skis,release  mass from previous arc come over feet and move  inside new arc  with pole touch to help re-centering   feel side cut of both skis to give a platform so balance is centre  to forward .

Keep moving mass inside arc ,joints aligned ,increase edging of skis  , lateral movement of all lower joints  so balance is centre  ready for loading in fall line .

increase edging angulation to get skis to full flex ,keep good alignment  ,feet /steer  for direction balance  centre .

for/aft = keeping  body joints of largest to smallest aligned on a vertical axis and platform.

Move mass across skis to release edges and to create edge angles for new turn,pole touch optional, keep body parts aligned to resist the forces that will be generated, utilize "steering" movements (ie leg rotation) as well as leg extension and flexion to adjust location of COM and maintain balance against experienced forces , adjust fore/aft position to direct application of force to portion of skis as desired?

I like that last post. How could you simplify it into a catch phrase that would allow you to focus on the concepts while skiing?

I use the word SWOOP.

Alot of info on technique, but I think the most important factor is really the ski.  If you have a ski with a soft tail you can rock your weight back as the turn progresses and continue to carve with the flexed tail, whereas if the tail is stiff you will accelerate in a straight line when your weight gets back.  The OP asked about the change in fore/aft balance, but what you can do and the results of your actions are dictated by the flex pattern of the ski, so there really is no single answer as to how you "effectively stay balanced" because it is relative. One ski will give you a pop in a straight line and interrup the end of the turn, while another will contine to carve an arc with the same weighting.

I think it works better if you break it down.  Whatever your perfect turn looks like, seperate all of the moving pieces that are going on in transition and work on them individually.  Progressively add them into your skiing rather than trying to master the whole thing at once. A good transition is the absolute key to skiing well, but unfortunately, there is a lot going on there!

Here's an example of what worked for me in my development.  I actually reversed steps 3 and 2 somewhat because I thought (incorrectly) that my countering and angulation was happening early enough.  Regardless, here's a working progression for my perfect turn.

Start with relaxation or flexion of the stance leg to release the turn.  This one move does so many good things.  First, it allows the forces of the previous turn to pull you into the next one.  No active movements or projectsions are required; it just works.  Second, if you continue to actively flex, that will allow the new stance leg to extend.  Assuming you know what to do with your edges, focusing on that one little movement will get you into the next turn with little effort and in pretty good position.

Once that movement is owned, focus on early hip angulation and early counter.  Immediately on release, start countering and get the hip angles that you need for the new turn.  If you do this fast and hard, you will be completely stacked at the top of the turn and in a very good position to manage whatever forces your are going to get based on how much pressure you are applying to your new edges.  Applying these movements early and agressively is the key to maintaining a quiet upper body.  When you are neutral in the turn (skis flat) you should already have your angles.

As you can see, transition is a busy time!  IMO if the movements aren't seperated and broken down, it is very dificult to grasp all of the things that need to happen.

Specific to fore and aft, the best thing to do is play with it. You have to learn what it feels like to be out of balance both forward and aft to understand where your balance is and how to move it around.  On easy terrain, try to lean and flex so far forward you pop your tails off the ground.  See if you can make a turn that way. Then try the reverse.  Try to get so far back you can pop your tips.  Can you turn?  Feel it with your feet and where you are in your boot.  Once you've got it figured out, start skiing on one ski.  What kinds of fore and aft adjustments are you making in order to turn?  How do these adjustments affect your ability to hold an edge?  How do they affect the shape of the turn?  When you can answer those questions, you can start using fore and aft to influence the bend of the ski in whatever way you require for the given turn.

Quote:
Originally Posted by justanotherskipro

I like that last post. How could you simplify it into a catch phrase that would allow you to focus on the concepts while skiing?

I use the word SWOOP.

Why don't you just think of it as "turning"? Not very catchy but I can imagine you don't want to be distracted.

Quote:
Originally Posted by oisin

Why don't you just think of it as "turning"? Not very catchy but I can imagine you don't want to be distracted.

I suppose if that works for you it is what you should say. In my experience the term turning does little to describe how the body and the feet are moving though. Especially when it comes to describing the the relationship between the path taken by the feet and the path taken by the body. Since the feet are moving across more distance than the body over the same period of time, they are moving at a higher rate of speed (distance / time = speed). Syncronizing these two paths so the body and the feet arrive at the next cross over at the same time is part of this dual paths model for a baseline turning maneuver. Feeling the feet moving one way while the body moves another is what the word swoop describes.

So having shared a baseline turning maneuver, what do you suppose happens when we vary our fore / aft stance through the cross over? If you look at modern reaching slalom turns you will see an aft stance at the cross over because the skis have already released and started accelerating as the direction change has happened long before the skis get flat and the cross over occurs. In this example, the body needs to catch up by the time the control phase begins. Allowing the body to take a short cut by allowing it to move further inside the new turn instead of slowing down the feet by pulling them back is something I was working on with BB this spring. It goes against a lot of conventional thinking but all I know is it allowed me to make some gates I otherwise would have missed. It's not a movement I would use for every turn but it does work in specific situations where a greater range of motion (laterally and fore / aft) is needed. It kinda reminds me of how a snowboarder can carve while almost laying down parallel to the snow. OOPs I'm rambling on here. My advice would be to experiment with the location of the cross over and the Dirt of the movements used to balance on the skis. Especially in the fore / aft and lateral arena.

New Posts  All Forums:Forum Nav:
Return Home
Back to Forum: Ski Instruction & Coaching