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Edging "Feet First" - Page 2

post #31 of 53
I don't mean to discount the wealth of info and posts. I read some, skimmed others.

My 2

What really determines edge angle is where your Center of Mass is in relation to the edge(s). Learning to get there without moving out of balance is best learned 'bottom up.' After that, edging is a function of balance and where the CM is directed.

I agree with SCSA in that skiing is all about balance.
post #32 of 53
Good addition Rusty!
post #33 of 53
John H and Roto - Excellent, excellent points. Upon thinking more deeply about this issue, I remembered that there actually are two relevant angles to this discussion, and that a few extra degrees of edge angle can indeed be critical.

The first angle involved is the one that the bottom of the ski makes with the snow. This is the obvious one that everyone thinks of and usually tries to maximize when they want to lock in a traverse or carve.

The second, and more critical angle can be defined in a bunch of ways, but the way that Roto just mentioned is fine: lets take it as the angle between a line drawn from the CM to the relevant ski edge and a line along the bottom of the edge/ski. Despite its extreme importance, almost no one thinks explicitly about this second angle.

Also, because few people distinguish between these two (related) angles, no common terminology has been established, specifically, which is called "THE" edge angle. Here, I'll simply call the first, angle "A", and the second, angle "B".

The reason that angle B is so important can be seen by considering a stationary ski on edge on a relatively steep hill, ie, you're stopped and balancing on one ski in the middle of a traverse.

Case I - no skidding:

For the skier not to fall over, the skier's CM must be directly above the point of contact with the snow. Now, if the skier can lift the downhill side of his ski slightly above horizontal, the little ledge that the ski has created in the snow will be slightly higher on its "air" side than on its snow side, and hence, the weight of the skier will tend to drive the ski further into this little snow ledge. He will not slip unless this little snow ledge can't support the weight of the skier and crumbles away. This corresponds to angle B being less than 90 degrees.

Case II - skidding:

If the skier lets the downhill side of his ski drop slightly below horizontal, the little ledge that the ski has created in the snow will be slightly lower on its "air" side than on its snow side, and hence, the weight of the skier will tend to drive the ski out of (and off of) this little ledge, and the ski is guaranteed to slip. This corresponds to angle B being on greater than 90 degrees.

The important thing to note is that the difference in angle A between the stable and skidding situations may be only a few degrees. If the hill is 30 degrees, angle A might be 32 deg in the stable case, and 28 deg in skidding case. Both of these numbers feel and look like a large amount of edge angle to the skier, so he may not make the effort needed to generate the extra few degrees of edging needed to lock into a traverse. (Note - the above numbers for angle A correspond to values of B of 88 and 92, degrees, respectively).

John H - With respect to your plus/minus 2 degree ankle angulation argument, my feeling is that for most people (not near their flexibility limits), its probably pretty easy to generate an 4 extra degrees of edging by more knee/hip angulation, but I agree with you that that the difference of 4 degrees between a floppy ankle and an active ankle can be extremely important. BTW, I think that plus/minus 2 deg is about the absolute maxim transverse slop you would have in modern boots.

In addition to the above effect, as was pointed out earlier, even small ankle movements within the boot almost certainly trigger or facilitate considerably more angulation further up the body.

Guys - this is a great thread. It certainly helped me clarify these issues in my own mind.



PS#1 - This discussion has caused me to wonder where exactly I (as an old fart) fit into the edging / flexibility spectrum. If I stand on hard level surface with my boots and skis on, say 8 inches apart, I can only achieve an edge angle of maybe 30 degrees (I'll have to actually measure it to be sure). This does not seem like much. How does this compare to other people? BTW, to compare apples to apples, I'm not interested in the case where you are very low, one leg is laid way over and the other is used as an outrigger. Obviously, you can get more edge angle this way.

PS#2: Here are a couple of assumptions that are behind the above discussion. I put these down here because, while important to some people, putting them in line above would interrupt the flow of the discussion.

First, for simplicity, I assumed that the metal edges of the ski have a base bevel angle of zero.

Second, for the purpose of this discussion, I've temporarily ignored carved turns or other dynamic situations. This is because the acceleration vector that these introduce must be added to gravity to determine the local, instantaneous direction of "vertical" that is most relevant to the interactions of the skis with the snow, and this would just obscure the simple discussion of angle geometry above.
post #34 of 53
Rusty Guy, if your extension is made to maintain contact with the snow you'll be performing an ongoing type of activity, which is what you want. If it's made too quickly, it becomes a push that's disruptive to balance.

Spag's push down on the right foot's big toe pad while lifting the left's big toe pad focuses pressure primarily on the outside ski, which is appropriate in SOME circumstances. My lift up on the outside of the right foot, or outstep (I've taken to referring to insteps and outsteps rather than the more traditional ball-of-the-foot pads behind the big toes and little toes), gets you the same edging action inside the boot while, for me, making it a bit easier to engage the left or right edges of both skis. Pushing down on pads seems to tension the leg more for me (making it muscularly stiff rather than skeletally strong).
post #35 of 53
Some great info, 1 thing that always bothers me some is the total isolation of movements and the right from wrong mentality sometimes. To be an expert you need to be able to move as needed depending on how out of balance you got on the last turn and what the terrain just surprised you with. Edging from the feet up is a great concept but unless you allow everything to move in concert it has accomplished nothing. I still feel that hip control is what is missing in most skiers. Much like walking the foot and leg can lead but you do not truly go any where until the hip moves. The hip needs to tip and lead but most skiers have it trail and twist. I think the ankle is the key in putting skiing the hip into postion but you need the ankle/thigh/hip to act as one. This is where movement assesment or needs anaylasis comes in. Some are good with one and bad with the others, you need to find which one needs to be focused on to improve the total. As a struggling golfer I improved my game on average of 5-8 strokes a round (this is not a infomercial) with advice that made alot of sense to me. The instuctor said don't think about were your hands are or the turn etc. Just swing with your whole spine and the rest will fall into place.

Soap Box: I too often see classes teaching endless exercises that are trying to fine tune movements that are not even there to begin with. We need to work from large gross movements to refined polished ones. To often people try to go the other way. If you get people just to move and have some freedom on there skis you have something to work. It is always amazing to me the lack of versitility in so called expert skiers. This IS the problem with PSIA centerline not in it's intent but in poorly trained instructors use of trying to get students to ski a way. This is the problem with HH method as well. Balan ce is the KEY but it is what you do when you get out of balance that seperates skiers. If you only have one movement to pull from you will be at a loss. That is the strength of the fundamental skills and skill blending. Experiment with movements, teach stepping, teach counterrotation, upperbody, steming etc... If you did not know that what Cold was how would you know something was HOT???

End of rant, todo
post #36 of 53
good post todo. You can't use your feet well when your CM is 2 feet behind your boots, can you?
post #37 of 53

Again, my comment was based upon the guy who helps my skiing (our SSD) and his contention is certainly smooth extension. In fact it is done in the control phase of the turn and is complete and the outside leg begins to soften coming out of the fall line as the turn is completed.

He hates "folded up" skiers with closed/articulated ankles,knees, or hips.
post #38 of 53
Kneale, to an extent you are right about the move focusing on the outside ski, but not all the way. It's just as important to lift the other toe, thus rolling the foot outward. Remember that I have only proposed and Exercise to establish a movement pattern by proposing a simple focus. It can get more complicated verbally if anyone wants to. Just an exercise...not a way to ski.

I also agree that this particular move isn't as skeletally strong, it's only to generate an understanding of how minute a move can be to change the attitude of a ski. Once a student understands that weight transfer and presure regulation can come from the feet and not the hips or upper torso, we can relax and feel the love. Thank you for pointing those things out! I needed to extrapolate a bit.
post #39 of 53
Spag, this is the catch 22 involved in any sports conditioning program. There are always going to be a few things that won't carry over. Lately, I have been giving myself the challenge of figuring out what the differentations are, and sometimes alerting my students to them (ex.: my post on the rounded back in The Tuck}.
Not an easy task.

Be Braver in your body, or your luck will leave you. DH Lawrence
post #40 of 53
Catch 22. Good way to put it. Any more I've started breaking it down into 2 categories...
1) If you get from point A to point B and MEAN to do it. That's a way to ski.

2) Everything else is an exercise.

That's pretty much the only way I can make things fun for everyone I teach. There's a time for exercises, and there's a time for tossing them out the window and stepping outside the box a little. We can talk about and drill edging manuevers until our clients fall asleep, but you have to cast our newly educated bretheren out into the world sometime. I'll admit that I can be a real Mother Hen sometimes when I'm teaching movements like this. I'm sure some others here do the same. Some students need to learn by finding thresholds, and sometimes they go too far and violate those thresholds. Can't help but admire the poor SOB's.(haha) anyway I'm off on a tangent. G'bye! <FONT size="1">

[This message has been edited by Notorious Spag (edited July 17, 2001).]</FONT>
post #41 of 53
The phrase describing that location of CM in relation to edges determines edge angle is in the PSIA manual. However! Many people do miss it as an important concept. Thus the continual focus on minute edging movements which of themselves cannot lead anywhere in lieu of balance as a few people have noted here.

At the risk of taking this, once again into a discussion of PSIA material etc etc etc....

The Skills Concept has (visually) put Edging, Rotary and Pressure Control Movements as central to the Skills Concept. The intention has been to show Balance as all-encompassing, but the point hasn't come across en masse. Most developing teachers teach to Edging, Rotary or PC because that is what the Skills Concept looks to be all about. Balance is that 'other', non-specific skill that will just 'come along' as the others are learned.

My Soap Box:
Balance should not sacrificed for the sake of edging, rotary or pressure control movements.

Teaching to the advantages of the new gear has caused me to tweak, or adjust the Skills Concept to a more current, more effective one. My Skills Concept shows Balance as central to the concept, with the other movements as peripheral. The other movements are mere functions of Balance. Not to say that they should never be taught to. Just to say that recognising the role and importance of Balancing Movements and teaching to them simplifies skiing and teaching immensely.
post #42 of 53
Roto, I agree totally. Balance, in terms of the movements that refine skills that enhance balance should be considered in that order. The edge angle IS is relation to the CM, and balance IS while in motion, with all the factors that apply.
post #43 of 53
Yes, there are FOUR (4) skills in the ATS Skills Concept. Balance being the most important.
post #44 of 53

My soap box for my own work: Balance should not be sacrificed for the sake of either srength or flexibilty.

Sort of like life.

Be Braver in your body, or your luck will leave you. DH Lawrence
post #45 of 53
I'm not an orthopedic surgeon, but I thought I would shed some light on the "ankle" topic. I am a Physical Therapist, Fitness Professional, and Ski Instructor.

The foot... One of my favorite topics. And ofcourse, it is a huge lockerroom topic. Is it the foot or the knee or the hip? What moves? My "belief" is that they work together. Although people are able to "focus" on one or even create more "angles" from a particular joint, the lower extremity joints are influenced by the others (the kinetic chain)and difficult to differentiate.

The ankle/foot complex is a very tricky topic. I always worn people in training to steer clear of it in any exam because the likelihood of burying themselves is substantial. Unless you really know it, you don't. This includes the trainers and the examiners out there too.

Without getting into the detail of Gray's anatomy, I would like to say the "ankle joint proper" is a hinge joint allowing for fore/aft movements. Very important for balancing activities whether static or dynamic. In the foot complex, there are a couple larger joints that allow for the side-to-side movements required for edging. Normally, a person has 20 degrees of moving to the inside (foot positioned on little toe side) and 10 degrees of moving to the outside (on big toe side.) Unfortunately, this is in the land of "ideal".

It is such a difficult area to deal with because soooo many people are not "normal". And this includes ski professionals. They have stiff joints not allowing movements or gumby joints as someone mentioned with too many movements. (There is also the influence of all of the muscles.) So something you feel in your own foot may not be felt by another person. You may have the "different" foot. Evaluate any injuries you have ever had to that extremity or even your back/pelvis.

Because of bony alignment and how the joints interact, movement of the ankle will create movement all the way up the kinetic chain. (Usually- depends on pathology) Someone mentioned something about knee movement only. This is not the norm because the knee joint is a hinge joint which does not allow for lateral movement unless you have had substantial collateral (MCL, LCL) ligament damage. Knee angulation is a result of ankle/foot and hip movements. If it's coming from the knee only, I would probably get it checked out.

Unfortunately there is no great research out there that really shows what's going on at the various joints during a turn. Anyone??

I hope this helps to clear up a few of the anatomy questions.

post #46 of 53
Okay, folks, I humbly step down as resident fitness expert. Excellent and informative post, and very much appreciated.

I have not found any studies such as the ones you spoke of. As I mentioned in my post about muscle fiber types in ski racers, most of my kinesiology classes have dealt with studies of other athletes, or dancers. Even in the Pilates post rehab program I am currently training with, most of the information about skiing ends up being stuff that I give out.

As both a fitness professional and a physical therapist, you have the opportunity to view exactly what is happening in people's feet, without their ski boots. And I agree, there are many abnormalities, even amongst fitness professionals. I sometimes wonder if this is due to all the extra anti pronantion, anti this, anti that devices they put in our shoes, when quite often they are not needed.

Your issues about the knee joints are interesting. It is both frightening and astonishing to me to observe how many people have a ridiculous amount of lateral hypermobility in their knees. Perhaps I just see it more often, given that Pilates classes often draw in the Yoga participants, who, depending on the technique, have "Lotused" their knee joints out of functionality!

Be Braver in your body, or your luck will leave you. DH Lawrence
post #47 of 53
More thoughts on this today. Is it possible that moving ONLY from the ankle without any follow through in the knee would lead to the same sort of torque injury as iniating the movement from the knee?
post #48 of 53
I only have a few seconds so I hope I can answer this. When you have movement of the ankle/foot complex, you have movement up the kinetic chain because of bony alignment. When you pronate your foot (weight on arch)the tibia (lower leg bone) will rotate in and when you supinate your foot (weight on outside border) the tibia will rotate out. And then the tibia will influence the movement of the femur (thigh bone) and so forth. So it's really hard to break things up and say nothing happens at a particular joint.
You mentioned you see a lot of lateral stability issues of your clients knee joints. Is is really coming from the knee, or is it being influenced from a poorly positioned foot or a hip joint rotation? It's nice to look at the posture without shoes.
I hope I answered your question. Please let me know. Gotta run.

post #49 of 53
Wow. GeorgiaPT
Welcome to epic. What a great start for your first post. Look forward to hearing more.
post #50 of 53

Regarding the lateral mobility thing, I need to think about this, because I am noticing it in my larger classes of 20+ Pilates students, which is way, way too big for that sort of class!
It is probably significant that I do not see this in smaller classes, possibly because I am able to correct more variables.

I do recall being in a Reformer workshop in Toronto with Moira Stott, and making an attempt to correct someone's knee alignment. After fussing around with various body parts with no sucess, Stott said to me, "Look at her feet". Sure enough, there was a minor misalignment in the feet that was causing "issues" in the knees.

This raises some interesting issues for ski instructors. Misalignments of the feet and ankles could cause problems in other areas.
But when a student is in a ski class, the EXACT alignment of the feet is the one thing a teacher cannot see, since the boot is covering them.

Be Braver in your body, or your luck will leave you. DH Lawrence
post #51 of 53
go to sleep LM!
post #52 of 53
Can't! Too much good stuff keeping me awake!
What's worse is I'm posting in between doing research related to some of the topics here. I can almost say that I'm working!

Be Braver in your body, or your luck will leave you. DH Lawrence
post #53 of 53
You are correct! Alignment concerns at the ankle/foot definately effect the knee and so forth. Even though you can't see your guests' feet, you have to train your eye for certain movement patterns during a turn or even walking around. If they are hugely pronated (collapsed inside arch), their knees goes to the inside and they hang out on inside edges a lot. They are REALLY good at hanging onto a turn!!! (For life) For people with supinated feet (on outside border), their knees bow out, and they are really good using strong rotation to initiate a turn and skidding their turns!!! Obviously the entire extremity is involved so there are exceptions to these ideas. But if you see something "not normal" you can always ask them. People usally know if they have flat feet . Someone probably tormented them about it.
It's nice to have cantable rental skis for the guests with huge alignment concerns. Especially for the never-ever. Otherwise they have a loooooong day ahead of them.

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