Flexing through transition (video)

[BornToSki683]

Nice breakdown into time slices which occur in moment by moment through transition. Getting warmer... ;-) In some cases you listed some specific muscle activated movements, directed by the skier, that facilitate this sequence in the first step or two...in some cases you described more of the outcome and didn't really explain what the skier needs to actually do to accomplish these outcomes...

With regards to flex-to-release...

These questions are meant to invite discussion and further detail, not to disagree with you...

3. The outside ski follows along like a dog on a leash, usually. It continues to tip more, just as the inside ski does. That leg shortens as well as it approaches the body.

focus on the underlined bit. What causes that leg to approach the body? What causes it to shorten? At what point in the turn? what external forces are present at that moment which would cause the leg to approach the body? what internal and/or external forces cause the leg to shorten?

4. Re: both legs/feet/skis are coming back up under you,

What causes the legs/feet to come back up under you? Where is the force coming from? what was that force doing a moment before it started moving your legs and feet to come back up under you somehow? if your leg is shortening because of an external force, what will the effect be on your CoM by virtue of the fact that your leg is shortening even as its coming back up under you?

each of them getting onto higher edges and each leg getting shorter to accomplish this. You'll be low in transition.

what causes each leg to get shorter to accomplish this? How does shortening both of your legs cause the skis to get into higher edge angles? I'm presuming you're talking about the uphill edges, the inside edges of the old turn at this point.

6. As the feet move up under the CoM/upper body, the body will continue forward down the hill on its already established trajectory.

How does the body continue down the hill on its already established trajectory? Aren't the skis trying to push your feet, which are pushing your legs which are pushing your CoM/upper body over towards the side of the run right about then?

Next question, what if you actually want and need your CoM to be pushed sideways across the hill, such as in TDK's video here, the skier does allow the CoM to be pushed sideways across to the other gate. What muscle activated and skier-directed movements will cause that to happen?

7. The whole body, moving as a unit with legs attached, progressively pulls the skis to flat.

I presume you mean here that as the skis are sliding across the hill and the CoM is somehow moving down the hill (crossing over), this momentum of the CoM pulls the skis off their old uphill edges to flat (and beyond as you went on to explain). So the question is, what needs to be done in order to ensure that this momentum of the CoM down the hill actually occurs and what will happen if its blocked in some way by body parts or a blocking pole plant, for example. What might block it? What would you have to do in that case if you blocked it?

what if the skier chooses, as TDK's video to have their CoM directed sideways across the hill? How will the skier be pulled onto flat skis and even further onto new edges?

 

[razie]

My skis cross my path because they are tipped onto their inside edges and the snow makes them turn, and as they cross under the path of my CofM, which has been released, they get tipped onto their new edges, due to my CofM being connected to them through my legs which become downhill from them.

Careful that you don't actually drag the skis on edge with your hips, but rather tip them actively from the feet, through flat and onto the new edges...

cheers

 

[François Pugh]

Careful that you don't actually drag the skis on edge with your hips, but rather tip them actively from the feet, through flat and onto the new edges...

cheers

Active tipping at transition is highly recommended, especially if done with GS skis at higher GS speeds while trying to see how far "upside down" you can get. There's not much worse than finding yourself heading downhill much faster than your skis when those skis are behind you and pointing across the hill.

 

[LiquidFeet]

Here goes. My comments in red. I don't know where you are going with this, so bear with me.
With regards to flex-to-release...
These questions are meant to invite discussion and further detail, not to disagree with you...

3. The outside ski follows along like a dog on a leash, usually. It continues to tip more, just as the inside ski does. That leg shortens as well as it approaches the body.
focus on the underlined bit. What causes that leg to approach the body? The skier's outside leg is attached to the pelvis which is attached to the inside leg. Leaving it behind is not an option. What causes it to shorten? The skier. At what point in the turn? At end of old turn, or start of transition, or at release, or just after apex/fall line, whatever words you prefer. what external forces are present at that moment which would cause the leg to approach the body? If it's edged, which the skier should make happen, the snow will push it along as FP pointed out upthread what internal and/or external forces cause the leg to shorten? That foot is trying to keep itself attached to the human it belongs to, so it comes along like a good puppy. Or the skier.

4. Re: both legs/feet/skis are coming back up under you,
What causes the legs/feet to come back up under you? The skier edges the skis so that they come around; intent counts. Where is the force coming from? The skier's search for sensations that thrill. what was that force doing a moment before it started moving your legs and feet to come back up under you somehow? The skier squirted those feet waaay out there. if your leg is shortening because of an external force, it isn't; the skier is shortening it what will the effect be on your CoM by virtue of the fact that your leg is shortening even as its coming back up under you? Really?

each of them getting onto higher edges and each leg getting shorter to accomplish this. You'll be low in transition.
what causes each leg to get shorter to accomplish this? The skier. How does shortening both of your legs cause the skis to get into higher edge angles? It doesn't. I'm presuming you're talking about the uphill edges, the inside edges of the old turn at this point. I did forget to say that, didn't I? I was trying to be brief.

6. As the feet move up under the CoM/upper body, the body will continue forward down the hill on its already established trajectory.
How does the body continue down the hill on its already established trajectory? The skier chooses to do this. Aren't the skis trying to push your feet, which are pushing your legs which are pushing your CoM/upper body over towards the side of the run right about then? Not if you are bringing your feet up under you, and paying attention to keeping your upper body moving along on its established trajectory. Borntoski, you are phrasing these questions as if the skier's intent is irrelevant, or at least submissive to the forces at play. I prefer to think that the skier is manipulating/controlling those forces in order to ski a chosen line.

Next question, what if you actually want and need your CoM to be pushed sideways across the hill, such as in TDK's video here, the skier does allow the CoM to be pushed sideways across to the other gate. What muscle activated and skier-directed movements will cause that to happen? Dunno.

7. The whole body, moving as a unit with legs attached, progressively pulls the skis to flat.
I presume you mean here that as the skis are sliding across the hill and the CoM is somehow moving down the hill (crossing over) somehow?, this momentum of the CoM pulls the skis off their old uphill edges to flat (and beyond as you went on to explain). The tilted body tilts the skis. Think: Leaning Tower of Pisa attached to ski boots and skis. So the question is, what needs to be done in order to ensure that this momentum of the CoM down the hill actually occurs The skier times things right and what will happen if its blocked in some way by body parts or a blocking pole plant The skier be sorry, for example. What might block it? Dunno. What would you have to do in that case if you blocked it? You have something specific in mind. What is it?

what if the skier chooses, as TDK's video to have their CoM directed sideways across the hill? How will the skier be pulled onto flat skis and even further onto new edges? Different turn strategies produce different results.

 

[BornToSki683]

You get an A for humoring me with answers to the questions, which were kind of all over the map but also designed to get us thinking... I didn't get the answer I was hoping which was specific bio mechanical instructions for the skier, to orient everything in the right way together with external forces, to accomplish the outcomes you listed. ;-). Yes intent matters of course, but intent doesn't tell you how to do it. I'm asking you to identify the specific bio mechanical efforts needing to be done by the skier in order to realize those intents. Saying "shorten" the leg, is not enough info, there are a few different ways to bio mechanically cause the leg to shorten, depending a lot on external forces present or not, with different results.

Let me say a few more things which might get us there. Remember, the point is to discuss the point of this thread, which is flexing through transition, of which there are numerous variations... A Ghost from the past already started eluding to the answer a few posts ago.. ;-)

so specifically we are talking about "flex to release".

Think about that line for a sec. How does flexion cause a release? Why does it cause a release and does it matter how and when you do it related to external forces that are happening in the turn? External forces are mainly gravity and centripetal snow reaction forces...

So consider this....

Remember...the skis can't make a turn at all, they can't squirt way out there and then loop back around to cross under you, without snow reaction force under the edge. What causes that? Mainly, at any given moment, our momentum is trying to move our CoM a certain direction, we position our skis on the snow in such a way and maintain functional tension in our body so that this momentum will plow into the snow, cause an equal and opposite reactionary force from the snow. That causes the ski to change direction, and the very functional tension in our body that is required to convert that momentum into turn forces, and speed control forces...that same functional tension will transmit the forces up from the snow to the CoM and push the CoM in a new direction and controlling its speed.

So even if the CoM appears to be moving straight down the fall line, its actually being pushed on the right side, then the left side, then the right side, then the left, etc.. And if you're controlling your speed the CoM is being pushed up the hill also! ( or I should say its being pushed back against the direction its trying to go ) When its pushed to the right, the snow will push back and through that functional tension in the body push the CoM back the other way. If it doesn't do that at least partially, pressure will be lost and the ski will stop turning!

The fact that the CoM may appear to travel straight down the fall line is an illusion...yes its moving straight down the fall line, but its being pushed on from side to side and then we do certain bio mechanical actions to maintain that illusion that the CoM is just floating straight down the fall line even while acheiving snow reactionary forces from the momentum of our CoM that causes are skis to turn and causes us to control our speed also.

So... what are those bio mechanical movements given that we have these external forces pushing on the right and the left? When do we create functional tension in the body and when should we release that tension (there's a big hint), so that the illusion of floating down the fall line while our skis cross under infinity style underneath us? How should we respond to those external forces? what body parts do we manipulate to effect functional tension on or off and when in the turn?

And additionally if as we come out of the belly of a turn our CoM is being pushed to the right, for example, how do we get it to move down the fall line faster then gravity would take it? You described that we need that to happen in order to crossover the CoM and unedge the skis and get them to the new edges. Great... That is the crossover. But its not a given that crossover will happen, many a skier gets stuck without the CoM moving across effectively. Why? If we are controlling our speed, then there could be points in the turn when the snow is pushing our CoM up the hill away from crossover. What do they need to do bio mechanically and when to facilitate that and how does the timing of that relate to what you're doing to maintain the illusion of the CoM moving straight down the fall line?

And then take TDK's video where the CoM is not moving straight down the falline, but in that case the intent of the skier is to get across from gate to gate..so there must be some subtle or not so subtle differences in what they are doing bio mechanically to acheive that intent with all of the above forces at play as well as the need for the CoM to crossover to change edges. What might that be? I will submit this is a lot about the functional tension, when and how to manipulate it. You got this!

 

[LiquidFeet]

OK. This is going to be long. Sorry.

BTS posted: "And additionally if as we come out of the belly of a turn our CoM is being pushed to the right, for example, how do we get it to move down the fall line faster then gravity would take it? You described that we need that to happen in order to crossover the CoM and unedge the skis and get them to the new edges. Great... That is the crossover. But its not a given that crossover will happen, many a skier gets stuck without the CoM moving across effectively. Why? If we are controlling our speed, then there could be points in the turn when the snow is pushing our CoM up the hill away from crossover. What do they need to do bio mechanically and when to facilitate that and how does the timing of that relate to what you're doing to maintain the illusion of the CoM moving straight down the fall line?"

1. GRAVITY
When I make these turns I've described, which is the source of my thoughts on the subject, my body/CoM does NOT travel faster than than gravity would take it. I am not pushing my CoM ahead down the hill. Are you thinking that propelling the upper body/CoM down-the-hill is a part of the turns FP and I have described? That's not it. Momentum plus gravity carry it over the skis when the feet get to the right place beneath it.

2. BLOCKAGE
You have brought up a "blockage" that gets skiers stuck when they are trying to learn this movement. You say a crossover is not a given; by that I think you mean that they may hold their bodies back up the hill of their feet. Yes, I've certainly seen this in students. It can be stunning the levels of hold-back a student can enact when they aren't used to letting the body cross the skis at the start of a turn.

Aside: I often use the drill of lifting the "downhill"/new-inside-ski tail to start a turn. When intermediates successfully lift that tail (not the tip), their bodies as a whole do tilt downhill and their uphill/new outside ski does tilt onto new edges along with the body. The cross-over happens because of that lifted tail. Usually. But some folks lean waaay back uphill when they lift that tail (or tip), balancing on the little toe edge of their uphill/new-outside-ski -- because it's so habitual to not cross over the skis. Unacknowledged (or acknowledged) fear keeps them in that leaning-back-uphill position, even though doing that requires balancing on the LTE. Amazing to see, and so frustrating when trying to teach someone to just DO IT.

My question for you, BTS, is this. Are you teasing out a discussion on how to teach someone who does this to allow that body to move downhill across the skis? That is a very big issue for ski instructors. It's a BIGGUS DEALUS, someone on Epic used to say. I'd love to hear what others do to teach this.

3. WHY
You ask why do people lean back uphill? I had a woman tell me once that she thought she'd go faster if she leaned forward. There's a window into the soul! Fear, caution, terror. That's why.

4. PUSH
You do point out that the snow is "pushing" our CoM uphill. Now that's an odd statement. The snow is resisting being shoved downhill by the edged ski. Little crystals of snow get pushed together by the ski, and their molecules refuse to merge because of electromagnetic forces. At that point a dense platform of smushed snow particles builds up and says "no" I won't go any farther, and the tipped ski moves along on that platform in a curved path. The snow does not communicate with the upper body, it communicates with the ski/boot/lower leg, up to the knee. From there up, there are joints that the skier can allow to bend or not in all kinds of directions. So the snow does not push the CoM anywhere. The skier is in control of the CoM.

5a. STRAIGHT
I don't remember saying the CoM moves straight down the fall line. In a pivot slip, yes. In these turns, it moves along a sinuous line leftie-rightie, down the hill. The feet take another sinuous line down the hill. Recognizing the line the CoM takes requires seeing things from the ground up. When one does this, the stable hill is the frame of reference.

5b. FRAME of REFERENCE
My description involves seeing things from the CoM down. The CoM is my frame of reference in my descriptions. The feet move around in a sideways figure 8 beneath the stable (from this frame of reference) upper body/CoM. Bob Barnes has animated this clearly in a video. He calls the move of the feet the "infinity move." In this video, he represents the skier at the beginning from the frame of reference of the hill. About 3/4 of the way through he shows things from the frame of reference of the CoM.

6. BIOMECHANICS
You are asking for a more precise biomechanical answer to what body parts a skier moves, and when, to get the CoM to move across the feet, yes? I'll answer that from the frame of reference of the CoM. The skier moves the feet in a sideways figure eight beneath them. This can be practiced on flattish terrain. I'll tell a story to illustrate.

One fine spring morning in April, the last day my mountain (Wildcat) was open, I took a left turn onto trail named Wild Kitten. It was warm out, and Wild Kitten was ungroomed. It's a long green trail that swings out and around at the bottom of the mountain, a very flat green trail. The snow was soft and sticky; my skis sank a few inches. .......Only one skier, probably a patroller, had skied the trail. He had made perfectly formed, very small round turns in the snow. I worked hard to match his tiny round turns. You can see tracks like the ones I left below, but they are waay bigger than the turns I was matching. What these tiny round turns required, on my all-mountain skis, at that very slow speed, in that gloppy snow, I discovered, was moving my feet around under me in a sideways figure eight.

The biomechanical thing I had to do was to "scoop" my feet out and around, back to front. Feet are attached to legs, but my focus was the feet. This "scoop" feels like a "pulling" of the feet forward and around, from back behind.

--Pull the feet from behind the body to just in front of the body. Do this on an "out and around" path, say over on the right. This makes one side of the sideways figure eight (infinity move).
--During this pull, legs start short, extend out to the side, then shorten.
--Bend ze knees extra as they come around up under you. This allows the upper body to keep moving on its path down the hill, which is over the skis.
(Not necessary in regular turns on a pitch; this was slow gloppy travel.)
--The momentum of the upper body moves it straight ahead across the skis (no pushing of the body with muscles).
--The feet end up behind the body again.
--Pull them forward on an out-and-around path on the left this time. This makes the other side of the sideways figure eight.
--Repeat.

Now these turns were on flat terrain, in gloppy snow. They required a ton of muscular work. With more pitch and momentum, I discovered later that much less muscle is necessary. Which muscles? My abs, hip flexors, erector spinae, and glutes were so sore from those turns that I could hardly move that night. It had been the last day of the season, and I was in prime shape.

 

[Don Duran]

Microsoft is developing a tracking device to answer all your questions BTS. Not sure of a release date though. Stay tuned to PSIA's site for that announcement.

 

[BornToSki683]

The main and original question is actually quite simple and hasn’t been answered. What are the bio mechanical movements that result in the infinity move. I dare you to take a crack at it jasp

 

[BornToSki683]

Lf I’m not at a computer terminal to answer your long post properly but I will later. In the meantime I am curious what others may have to say.

 

[Fishbowl]

I like the concept of “functional tension”. That’s made a lot of little pieces of the puzzle finally fall into place for me.

 

[BornToSki683]

My question for you, BTS, is this. Are you teasing out a discussion on how to teach someone who does this to allow that body to move downhill across the skis? That is a very big issue for ski instructors. It's a BIGGUS DEALUS, someone on Epic used to say. I'd love to hear what others do to teach this.

well we can talk about how to teach it once we come up with some understanding of what it is we want to teach exactly. What are the bio mechanical movements? We might not agree on what those are I guess...but anyway let's try to start there. How to go about teaching it, is another interesting discussion. I reckon you are trying to avoid discussing bio mechanical movements, but are expressing an outcome and hoping that yourself and others will intuit the right bio mechanical movements to pull it off. I'm trying to invite some exploration into what those bio mechanical movements actually are.

I am interested at the moment about the thread topic of flexing through transition. Why do we do it, how do we do it...WHEN should we do it exactly. We got a little off track talking about cross under, which led us to infinity move, etc.. but then I realized, it may not be that far off track, as flexing to release is involved in that too. how and why?

PUSH
You do point out that the snow is "pushing" our CoM uphill. Now that's an odd statement. The snow is resisting being shoved downhill by the edged ski. Little crystals of snow get pushed together by the ski, and their molecules refuse to merge because of electromagnetic forces. At that point a dense platform of smushed snow particles builds up and says "no" I won't go any farther, and the tipped ski moves along on that platform in a curved path. The snow does not communicate with the upper body, it communicates with the ski/boot/lower leg, up to the knee. From there up, there are joints that the skier can allow to bend or not in all kinds of directions. So the snow does not push the CoM anywhere. The skier is in control of the CoM.

HOW does the skier control the CoM? What bio-mechanical movements to you employ in concert with external forces to control the direction it goes?

How is the CoM made to travel on an shaped line...or if you were going straight down the fall line even, how does the skier make the CoM do that? Because left entirely to its own devices...the CoM would be pulled by gravity straight to the center of the earth passing right through snow and earth and everything in between. But it doesn't do that in skiing, the CoM is redirected and we do certain things with our body that causes interactions with the physical environment, to cause the CoM to take a path different then directly to the center of the earth. What are those movements? Specific to this thread:

1. what do we do bio mechanically to facilitate the CoM crossing over the path of the skis in transition?
2. what do we do bio mechanically in response to turn forces, so that the amount of displacement of the CoM across the hill is controlled by us?

BLOCKAGE
You have brought up a "blockage" that gets skiers stuck when they are trying to learn this movement. You say a crossover is not a given; by that I think you mean that they may hold their bodies back up the hill of their feet. Yes, I've certainly seen this in students. It can be stunning the levels of hold-back a student can enact when they aren't used to letting the body cross the skis at the start of a turn.

I've seen it in students, high end skiers and many instructors too. So.. what are they doing bio mechanically that causes this to happen. HOW does a good skier "let" their body cross the skis? What is the bio-mechanical operation that let's or allows that to happen?

STRAIGHT
I don't remember saying the CoM moves straight down the fall line. In a pivot slip, yes. In these turns, it moves along a sinuous line leftie-rightie, down the hill. The feet take another sinuous line down the hill. Recognizing the line the CoM takes requires seeing things from the ground up. When one does this, the stable hill is the frame of reference.

very good. what causes the CoM to take the wavy line?

FRAME of REFERENCE

I could care less about frames of reference, I am talking about external forces and bio mechanical actions we take to manage those forces in order to effect the movements of the skis and movement of the CoM. What are those bio mechanical actions, when, how and why? Frame of reference discussions are a waste of time.

My description involves seeing things from the CoM down. The CoM is my frame of reference in my descriptions. The feet move around in a sideways figure 8 beneath the stable (from this frame of reference) upper body/CoM. Bob Barnes has animated this clearly in a video. He calls the move of the feet the "infinity move." In this video, he represents the skier at the beginning from the frame of reference of the hill. About 3/4 of the way through he shows things from the frame of reference of the CoM.

Ok I understand you are trying to use a frame of reference as if the CoM is not moving and you are just hanging there in space while you push your feet around in a figure 8. But that is simply not how it all works..there are external forces pushing your feet...and you have functional tension (or not) in your body that does push your CoM around. How you position your feet on the snow in relation to various external forces causes the skis to be controlled and ultimately that is how your CoM is controlled too. So while its somewhat interesting to imagine that a nice looking outcome of figure-8's under our CoM standing still...that still doesn't explain how to acheive it. There is more going on. That is the problem with these frame of reference discussions...they almost always leave out certain details which are relevant and important. It can lead to using the wrong muscles the wrong way.

BIOMECHANICS
You are asking for a more precise biomechanical answer to what body parts a skier moves, and when, to get the CoM to move across the feet, yes? I'll answer that from the frame of reference of the CoM. The skier moves the feet in a sideways figure eight beneath them. This can be practiced on flattish terrain. I'll tell a story to illustrate.

Yea, that's a case in point, unfortunately. Though I do appreciate that you made an earnest attempt to describe the bio mechanical activities employed by the skier in your view to achieve the infinity move. But I'm afraid that isn't it unless you're talking about when you're sitting on a chairlit and trying to describe it to someone sitting next to you.

How can you relate infinity cross under to the thread topic, flexing through transition?

 

[BornToSki683]

missed this one in my last reply:

Which muscles? My abs, hip flexors, erector spinae, and glutes were so sore from those turns that I could hardly move that night. It had been the last day of the season, and I was in prime shape.

I'm not surprised you were so sore as described. Skiing pow or anything else can be a LOT less physically demanding if you allow the external forces to do the work for you.

Manage the pressure appropriately and everything falls into place

 

[LiquidFeet]

Well, I was managing the forces "appropriately" to match the previous skier's tracks. There's nothing wrong with that, BTS.
My movements were exaggerated, and I learned to do them from that exercise. Nothing wrong with that, either, and nothing is wrong with being sore.
So there's no reason for you to imply I should have done those turns more "appropriately."
Letting the "external forces do the work" would not have resulted in my matching the turns of the other skier.

If you have a point to make about how turns should be done appropriately, it's time you made your point on your own.

 

[BornToSki683]

I think I already have! Numerous times. Guess we're done..sorry didn't mean to say you were doing anything "wrong", did you have fun?

 

[BornToSki683]

I like the concept of “functional tension”. That’s made a lot of little pieces of the puzzle finally fall into place for me.

Add to that functional relaxation, then speak about when to create functional tension, and when to create functional relaxation.... when and how...then we'll be getting somewhere!

 

[Doby Man]

@BornToSki683 , I realize that you already know this but also seem to be drifting away from the fundamentals. There should never be so much discussion on biomechanics without labeling them exactly what they are. The main biomechanical movements in skiing are the five/seven +/- of alpine ski fundamental movements:

Angulation (separation)
Inclination
Flexion (separation)
Extension (separation)
Rotation (separation)
Tipping (& skidding)
Fore/aft pressure control

The reason why these terms of movement are labeled as “fundamentals” is because skiing cannot happen if it is missing any one of them. Note how many are linked to “separation” which is the number one coordinational fundamental for all athletes in most sports. How these biomechanical movements are integrated with each other in the ski context can then easily be described as how they flow through the kinetic path of anatomical movement and further characterized by their DIRT. To go to the next step in detail, we can then trace each of these seven fundamental movements through the three turn phases and transition. And, of course, managing specific contexts for ability, turn type intent and terrain is a must as any shift in one is a complete shift to the entire paradigm as organic as it is. For me, this total structure would be a very thorough full page individual MA or could be used to fully describe an actual technical model. When a coach or instructor can establish a complete understanding of technique, all the movements and dynamics, through these basic tried and true principles, they are then able to quickly and easily refer to it competently under any circumstance thrown at them while never contradicting themselves in the process. Whenever someone is asserting a certain concept you’ve never heard before and you can quickly process it through the fundamentals, kinetic chain, turn phase and specific contexts, you can then make a competent judgement on the spot as to whether it is worth its salt. All your questions in the above posts can be answered through these simple paradigms. I highly recommend it.

BTS: “what do we do bio mechanically to facilitate the CoM crossing over the path of the skis in transition?”
The crossunder is primarily biomechanically facilitated by angulation and the crossover by inclination. We respond to the lateral portion of turn forces with a skill blend of angulation and inclination along with ski tipping. The former morphing into the later based on turn intent how the turn progresses.

BTS: “what do we do bio mechanically in response to turn forces, so that the amount of displacement of the CoM across the hill is controlled by us?”
The CoM is ALWAYS controlled by us. It’s just that we rely on the turn forces to provide us the timing and power to fund the movement of our CoM. In a SL turn, a combination of mostly angulation and flexion with only well-timed hints of inclination and extension. Both hints of which, cannot be seen behind the dominant angulation and flexion because they each reside on the same scales - ang/inc and flex/ext.

We respond to the vertical portion of turn forces with a biomechanical skill blend of extension and flexion. The goal to the ultimate skill blend of flexion and extension is to be able manage a vertically steady CoM through retraction and over undulating terrain.

 

[BornToSki683]

@BornToSki683 , I realize that you already know this but also seem to be drifting away from the fundamentals. There should never be so much discussion on biomechanics without labeling them exactly what they are. The main biomechanical movements in skiing are the five/seven +/- of alpine ski fundamental movements:

Angulation (separation)
Inclination
Flexion (separation)
Extension (separation)
Rotation (separation)
Tipping (& skidding)
Fore/aft pressure control

Oh my gosh those are certainly not the only bio mechanical things happening in skiing.... those are very broad categories. In some cases they are outcomes also...not bio mechanical instructions.

The reason why these terms of movement are labeled as “fundamentals” is because skiing cannot happen if it is missing any one of them.

its not a bad list of fundamentals in a broad sense, agree...but again...accomplishing them involves more specific information about body parts. So try to relate what I have said so far....and what the thread is about...flex to release...to the skill categories you embrace above.

BTS: “what do we do bio mechanically to facilitate the CoM crossing over the path of the skis in transition?”
The crossunder is primarily biomechanically facilitated by angulation and the crossover by inclination. We respond to the lateral portion of turn forces with a skill blend of angulation and inclination along with ski tipping. The former morphing into the later based on turn intent how the turn progresses.

you really lost me there. Can you please elaborate? inclination to facilitate crossover? Angulation to facilitate crossunder? how? That is non sensical to me right now but maybe you can make sense out of it. Can you relate that to flexing through transition per the thread?

 

[Uke]

BTS,

You seem to use 'flexing to release' and 'flexing through the transition' interchangeably. To me they are two different things, do you view them and being the same thing?

uke

 

[BornToSki683]

Can you explain the difference between those two things as you see them? I’m not saying yet whether I agree or disagree, I need more clarity on what you mean exactly.

What I can say is that if you are flexing through transition then you are probably flexing to release just prior to transition. So they do go together in my view it’s presumed that if you flex to release you will be flexed through transition and visa versa if you are flexed through transition then you must have flexed to release just prior. It’s all connected. Let’s observe tdk’s video what they are doing.

How do you see it?

 

[Uke]

Have to keep this short as I hope to ski tomorrow.

What 'flexing to release' does is change the trajectory of the com, release it from its former path if you will. What it doesn't do by itself is release the edges.

I can 'flex to release' then flex even more to allow my body to cross the path of my feet.

I can 'flex to release' then slow or stop the flexing and produce a "vault' that will accelerate my com up. Depending on the strength of the vault I may continue to flex or I might have to extend to maintain snow contact through the transition as the paths cross.

I can release the edge and the com at the same time by flattening the ski at the foot. Again with this move I can then flex or extend through the transition as necessary to achieve early edge engagement.

Hope that makes things clearer,

uke