Rotary, active vs. passive

I'll bite..

Balance on one foot, lift or even just lighten the other foot. Then tip the lighter foot to the little toe side and pull it back.

I defy you to not have to fight to keep the foot straight. It will turn.

As I explore more and more of my skiing, I have been told to pull this the foot back, engage the little toe side, and guide the inside ski through the turn.

Generally unless I'm trying to make a very short radius turn, the guiding I find happening is in the form of keeping the ski from diverging not making the turn tighter.

From what I've read, played with, and learned is that there are specific "primary movements" that if they become our "go to" or "default" movements then many of the other movements will follow.

As PSIA moves and evolves I am finding that the better and enlightened coaches I have encountered are all talking about movements or movement patterns rather than skills. Yes the skills are there Balance, Edge, Rotary, Pressure. But it's how we blend the skills to create MOVEMENTS that change our skiing for the better or worse.

PMTS is a teaching system that works on how to use these movements. Much more structured but I also find a little confining especially while teaching if you have students that are not "motivated" to spend time practicing movements and doing drills. Most of the public wants the thrills of skiing without the sweat or practice time.

Bud it's all about the balance. Since this seems to be a very difficult concept to communicate, I suggest you make some skidded turns both ways (steering vs tipping) on video so you can see for yourself.

This is really well worded. I like. During ESA Tahoe I was trying to build a short turn. While we had joked a lot about "un-approved" teaching methods (since both WTFH and I were discussing PMTS movements), it shows where we were coming from with our current movements. Robin never told me to rotate or actively move my legs to create the short turn though. She wanted me to "soften" the outside leg. She said I was making really good carved turns, but I wouldn't be able to get any shorter without this change (that I didn't really understand yet). I didn't get it until almost the end, but when I did it was like magic. Soften/relax/whatever you want to call it reduced the edge angle. As long as my other movements were correct this created much more of a "brushed" turn.

This seems to be another place where the end result is the same even though we use different terminology to get there. For the skier who is willing to work hard and do drills in their own time PMTS definitely leads to really good (expert, if you will) skiing. At the end of the day it looks like both camps are still teaching very similar movements.

BTW, after a half day with another of Mike and Robin's pals at heavenly ski school I'm really feeling good about my off-piste skiing. I did a number of double blacks at Kirkwood yesterday, and it was fun (rather than scary). I still can't link short turns on those kind of steeps keeping them as narrow as I'd like, but there's always next season!

-Adam

In PMTS (and in other systems as well) rotary is not thaught as a movement in means of torcing skis into turning. To my understanding PSIA (and some other systems) are doing that. That is the difference. There are other interesting differences also, like the active and passive weight distribution. In PMTS active weight distribution is called couterbalancing and is regarded as the 4th of the 6 essentials of skiing in new HH book while that is a strict nono in PSIA. This would make PMTS a active weight distribution and passive rotary technique. PSIA would be a passive weight distribution and active rotary technique.

I don't think I would categorize counter-balancing as a strict no no in PSIA FWIW. For those not sure counterbalancing = angulation, more or less.

Bud, good topic, I hope it can stay civil. My impression is that there are many people that only have a partial understanding of these issues, but are passionate about their approach, which is why we often end up at a stale mate on the point about active vs passive rotary.

But I do think it comes down to the fact that in PMTS they do not advocate actively steering with the legs. There are numerous PMTS movements which do result in rotation..both the femurs in the hip socket as well as the skis on the snow. However, their focus is not on actively steering with the legs, it is on using other movements which create changes in dynamic balance that may result in these rotational outcomes.

I really think PSIA is an organization rather than a system. One PSIA instructor of unknown cert level talked about steering (which to me = rotary), but didn't teach any during that lesson. Neither of the PSIA L-3 instructors I have worked with taught any active rotary. They both taught active counter balancing.

As a SCUBA instructor I get a lot of questions about which certification agency gives the best instruction. I always tell them that the agency is irrelevant, and the variance from individual instructor to instructor is MUCH greater than the variance from system to system. Find an instructor who has been successful with students who have the same goals as you, and you're likely to have a good match. Is skiing any different than diving in this area?

-Adam

Hi Bud,

I joined to take part in Max501's thread,then found it's not so easy to get your thoughts into words, especially if the ground keeps shifting!

Here's my take on rotary.I believe it is possible to generate rotary motion of the skis by linear movement of the feet- tipping and pullback.

Imagine an armoured tank viewed from above - the tracks can only move in a straight line relative to the tank. To turn, one track moves faster than the other. The tracks then skid on the ground to allow the tank to turn. Indeed, if the tracks move in opposite directions at the same rate the tank would spin on the spot! The ultimate in rotary motion generated by linear movement.

To try and translate into skiing -
Imagine both skis tipped onto their right edges, parallel and we're curving, I'm old fashioned so most pressure is on my outside ski(left) and I've an inside ski lead
If we keep everything else the same(hips, upper body),pull the inside foot back. This loads the inside ski tip making it flex more which tightens the radius of it's arc.If we keep internal muscular tension to bring the outside ski with us in the tighter arc, but keep the same edge angle and pressure, the outside ski must brush, skid, slip, pivot or whichever term seems appropriate, to follow the tighter curve.

As an unfit,creaking 50yr old looking for the most efficient(= effortless) way to ski PMTS seems to have its merits. The simple tipping and pull back movements are easy to do and calibrate and are capable of generating powerful rotary forces for shorter arcs when needed.Of course you have to allow the foot to rotate with the ski which I think of as secondary rotation - easier and less effort than the complex muscle contractions needed to actively rotate the foot and the ski - Primary rotation.

I tried to incorporate Pmts into my skiing this year and when I got the timing right for flex/extend, it was effortless to initiate a new curve, and being fully extended at the bottom of the curve, I took the pressure increase stacked up on my bones. I managed to ski all day for six days! Good for me.

Cheers
Brian

I think you are right but I also think the movement concept has always been there.

Seems to me whenever someone quotes the PSIA skills quickly, they say four words "Balance, Edge, Rotary, Pressure". But, if my rusty old brains remember what the textbook version of the PSIA skills are, it is actually "Balance, Edging Movements, Rotary Movements, Pressure Control Movements". The movement concepts have always been there and you're leaving something real important out if you only quote the four words.

Have I a clue?

Oh, a quick search found something from TPS 2002 that has the M word after all the words including the B word--

http://www.psia.org/psia_2002/educat...assessment.asp

European take....

Simply tipping will not apply any rotary torc to your skis if you do it according to PMTS and TDK .

It is important to understand the difference between skidded turns and arched ones. In arched turns we follow our skis but in skidded turns the skis follow us. In order to get our skis skidding we need to do something to make the tails overstear (car term) and is a complex procedure. The following reasoning is based on arched mechanics.

Here's how you can test it right at your work desk. Sit in your weeled chair and place both feet on the floor pointing forward and with knees at a 90deg angle. Grab the desk with your hands and move your chair sideways. Notise how this movement is only tipping your feet as your butt moves sideways. Now from a neutral sitting position rotate the chair to one side. Notise as your knees start pointing in a new direction they start to pull on your front part of your feet on the floor and transmits that butt rotation to your feet (skis). If you only point your knees one or the other way same rotation torc to feet is applied. That is a femour in hip socket rotation. In other words, if we do not apply any knee angulation, pointing of the knees (femure rotation) at any part of the turn we do not apply any rotation eather. There is one more thing to consider, couter also called counter rotation or PMTS term counteraction. In my first example we were sitting in our chair moving it sideways but what we actually should do is counter and that we do by rotating the chair in the opposite direction of where we are moving it sideways. This has the opposite effect to pointing our knees into the turn and ultimately tries to perform rotation to our skis in the opposite direction, out of the turn. In other words, when all these movements are used in skilled proportions rotation can be added or removed at any time.

The mecanis are that as long as the lower foot up to the knee joint stays perpendicular to the ski base no torc in form of rotation is applied between ski base and snow. As soon as the knee (leg) moves faster, the knee drives, rotational torc is applied. If you drive the edging by angulating your vrist your knees will lagg behind and some knee pointing could be done without rotation. HH has all this figured out and if he sais that he is not using any rotation to drive his turns we should listen up.

In austria we used to practise "dwarf turns" which is a drill aiming at getting your knees loose, flexible and working. That was exclusively for short turn purpose. I would call that a rotary movement according to my definitions above. I can PM a video if someone is interested.

Bud, I think that one of the root problems for the difficult communications on this topic is the term rotary, as well as associated terms such as steering and guiding. At best they are inexact and at worse they mean very different things to different people. I have initiated threads and posted on this topic many times. In response I have received separate references/definitions from PSIA literature on rotary referring to joint rotation and the application of a twisting force in the plane of the ski. On the far other side are some who almost entirely deny the need of any kind of rotary (whatever that means!) at all in skiing. My suggestion would be to eliminate the use of these terms if you really want to discuss the underlying topic. It is very simple to restrict ourselves to more exact terms for actions/forces we can apply to the ski (tipping, twisting, combined twisting and tipping, pressuring fore or aft, unweighting, etc.). Similarly it is very easy to describe joint movement (i.e. internal rotation, external rotation, flexion, extension, supination, pronation, etc.). If people would more specifically use these terms to describe the movements they are talking about and the actions/forces they are trying to transmit to the skis I believe we could have much more meaningful discussion.

Furthermore I think that it is important to differentiate between active muscle recruitment needed for a movement (whether to initiate the movement or to continue the kinetic chain along the intended path) and reduction of muscle activity or relaxation to permit joint movement. I would hope the reason for this is obvious. However, I think it may be worthwhile to further differentiate between movements which may happen without "effort" as part of the intent of a movement, and those that must be purposefully performed within a movement, recognizing that this can be different for different people.

[quote=dchan;698528]I'll bite..

Balance on one foot, lift or even just lighten the other foot. Then tip the lighter foot to the little toe side and pull it back.

I defy you to not have to fight to keep the foot straight. It will turn.

As I explore more and more of my skiing, I have been told to pull this the foot back, engage the little toe side, and guide the inside ski through the turn.

Generally unless I'm trying to make a very short radius turn, the guiding I find happening is in the form of keeping the ski from diverging not making the turn tighter.
[quote]

When I was skiing with Wigs in Aspen he talked about the same thing - that it was not possible to tip the ski without turning it some. We stopped and played around for a while. He demonstrated this concept to me while standing still on skis. He could not tip his ski without turning it to some degree no matter whether it was very lightly weighted or just lifted. I could do so quite easily. He was surprised.

Was it a difference in our physiology, equipment set-up, training, ...:

I guess I've always been defiant to some degree ever since my early youth

See page 143 of "essentials" : "Can We Really Tip without Turning?"

There is a lot of pertinent info there.

I find the most confusing aspect of this discussion to be trying to work out what constitutes good, active rotary to those who believe such a thing exists.

There definitely are movements in PMTS in which the skier's muscles cause the skis to rotate. Tipping creates torque on the skis because it recruits rotation of the thigh and ankle muscles. Pulling back the inside foot moves the point around which the outside ski is rotating forward and slows down the inside of the body relative to the outside. Counteracting creates some turning force as the legs unwind under a stable upper body. There are more, no doubt. But by Harald's definition all of these are "passive" side-effects of movements we perform for some other primary purpose. At slow speeds and low edge angles PMTS skiers rely on these rotary forces to get the skis turning, but at higher speeds, as Harald says in the section of the Essentials that BigE cited, they become a threat to balance that has to be controlled.

So from my perspective, passive rotary can be good or bad depending on what else is going on in the turn. But what about active rotary?

There only seem to be two rotary movements that anyone believes should be taught in modern skis. Counteracting/counter-rotation, and rotation of the legs by turning the leg at the hip joint. I don't think there's any real disagreement that counter-rotation is a good and useful thing in short turns.

So it all comes down to rotation of the leg at the hip, and this is where I get confused. Whenever you see a good skier's legs rotating, they are also (unless they are doing a drill or demo) edging their skis at the same time. In PMTS we just talking about tipping, which primarily produces edging, but under some circumstances also add torque to the skis. So it seems that the real area of disagreement here is about turning flat skis. PMTS doesn't teach any way of doing this - when skis are turning, they are edged. But "traditional" ski instruction in the US does teach beginners how to turn their skis without edging them. Indeed, the whole idea of the gliding wedge/wedge christie/open parallel progression seems to be to teach leg rotation without edging first, and then add edging later.

Do I have this right? If so, what I wonder is, when it comes to upper level skiing, is there really any value in being able to turn a flat ski? I don't have much use for such a movement myself, but I'm only a reasonable recreational skier, so I'm asking the question seriously, albeit skeptically.

Or does something similar apply to leg rotation as applies to tipping, that when we try to make leg rotation movements, we also secondarily making tipping movements to stay in balance?

As I understand it, HH created PMTS because he didn't like the end result of skiers learning from sequence of the snowplow, to the christie, to the parallel turn. HH says there is a flawed movement pattern in skiers who learn from the snowplow on up. The snowplow forces people to do bad things: 1) Learn to ski with your butt sticking out, which is bad for alignment. HH stresses that an unaligned body is difficult to control on varied terrain and is inefficient, needlessly using up too much energy. 2) Learn to turn by rotating your outside hip, leg, knee and foot inside, which twists the ski into a turn.

HH says that these bad habits are very hard to break and adversely affect one's ability to become an expert skier.

Instead, in PMTS, HH advocates lightening or lifting the inside heel, tipping it toward the little toe edge, while pulling the inside leg back, with ankles even throughout the turn. These primary movements: 1) Keep the body in skeletal alignment, since the butt cannot stick out while you pull your inside foot even with the other ankle. 2) Efficiently let you use your full body weight to tip the ski on edge from its center, which engages the tip and tail of the ski, causing it to bend, which allows you to turn without any rotation.

One other thing and I'm outta here for the summer. HH should be given credit for emphasizing bootfitting and alignment. He's made a real difference helping to change the culture of ski outfitting to benefit people who struggled for years because they (and their instructors) didn't now they were misaligned.

FWIW -- I keep reading about rotary movements being a key difference between PSIA and PMTS when teaching students. Yet at the 3 ESAs that I have attended, I have never heard any of the instructors utter the "r" word. Whether during instruction or post skiing discussion, the concept of rotary movements has not come up. Not once. Alot of the conversation has been about balance, moving forward through the turn, and starting the turn with your feet. So what am I missing here?

PSIA teaches rotary as the main form of turning from day 1 with the gliding wedge. They don't have to mention it. It's already ingrained. /Have you ever heard "Turn the skis left to go left." The "turn" is a rotation of the skis.

Nothing, I suspect. If you read this forum regularly, you see very little mention of rotary movements, and I suspect the same thing goes for ESA. Many of the instructors and coaches who post here seem to use a style of skiing that is really very similar to PMTS skiing and therefore uses very little active rotary. The SkiBalance forum stuff in the supporters section and Bolter's ArcTech seem very similar in spirit if not necessarily in the details to Harald's ideas. We're mostly headed in roughly the same direction.

The system the PSIA promotes for teaching beginners, though, really does encourage rotary movements of the legs to turn the skis, as this is the basis for the gliding wedge christie and open parallel turns. Bob Barnes has explained this extremely well in various posts on the "Perfect Turn" and his comments on what he believes to be wrong with PMTS. From what I can judge from watching beginner's lessons, though, a lot of actual ski school teaching doesn't effectively teach these movements, and their students end up in a braking wedge anyway.

Prior to my first ESA at Stowe 2005, I had not taken a lesson in over 20 years. Since getting on shaped skis, I have not heard anyone speak about "turning" my feet at any point during the turn -- all anyone has harped on is putting the ski on edge and letting the shape of the ski do the work. ESA instruction has gotten me to be more active in using my foot rather than my knees or hips to tilt from side to side.

True but when one of flattenned and the other has a bit of edge less , little or no rotary is necessary . Then when you remove the wedge the skill is in the edging and the rotary gets more passive. Rotary is a necessary skill in skiing. A pivot uses some rotary as do many other mixed turn shape moves. As long as it is done with the lower body it is a skill not a vice.

The gliding wedge does not function without active rotary. You can see it on PSIA demos. I tried it this winter and I can verify it. PMTS does not allow wedging but in Austria simple ski relese and active weight transfer is thaught. The gliding wedge turns much quicker. I have it taped on video if someone is interested.

I learned via what was then called the snowplow, and it certainly did not overemphasise rotation over edging for me. However, I have learned that the modern "gliding wedge" is differentiated from what I learned as the snowplow. The angles used in the gliding wedge are small. The main method of changing direction is rotation of a near-flat ski. The modern gliding wedge goes automatically into a parallel turn that relies heavily on rotation of near flat skis. The reasoning is to avoid "negative" movements and a braking wedge. The result appears to be that students can come back later and pay for "advanced" lessons to learn how to use tipping as the main means of turning instead of rotation.

I don't believe he said "ONLY".

Is PSIA denying teaching rotary skills now too?

Passive, as in, meaning to do it, wanting to do it, intending to do it, and actively doing something that MAKES it happen, but pretending it just happened on it's own?



Huh? Counter balancing (angulation for you home gamers), moves a skiers balance point in the direction of the outside ski. That is it's purpose. To do that you HAVE TO move body mass toward the outside of the arc, or as you say, "away from the intended direction of the turn".

PMTS'ers train to really exaggerate this lean away move in the high C portion of the turn (beginning of the turn, home gamers), where the nature of the forces most demand it (or so it's said). Check out HH's slant board demos. I'm just a dumb country boy, but it looks pretty "active" to me.

For what it's worth, and as you can tell from my above post, I have a big issue with this "passive" term. Anytime something is purposely done with the clear intent to make something else happen in a very precise manner, I just have a hard time coining that action as "passive".

Passive rotary to me is when joints are articulated in a manner which includes a rotational element, but is done to allow the skis to be tipped on edge so they can carve, yet apply no rotary force to the skis.

Anything done that creates a rotary force that is intentionally meant to be applied in a controlled and precise manner to the skis to sharpen the turn into a very specific shape,,, no matter what method is used to create that rotary force,,, well ,,, in my mind I just can't see it being anything but "active".

What you really should be asking is what PMTS does differently to produce that active rotary force so they can brush their carves