Schlopy

[Biowolf]

The best use different movements, they use a combination of lateral foot, ankle and passive (following) leg movements. These movements are accomplished with co-contraction of the antagonistic muscle groups around the key joints and a phenomenon called loose adoption before co-contraction is established. Loose adoption is a form of relaxation. It happens at the joints and the mid body to assist in developing alignment of the body to the ski edges. This action creates angles, alignment of the joints and of the body, to resist forces developed in the critical part of the turn.

Harald, can you PLEASE explain this in detail. Also it would be great to know what you did to Schlopy's boots.

[John Mason]

no replys - I'll take a stab - and watch for corrections/clarifications

co-contration:

This is when both opposing muscle groups around a joint are contracted. As an example that you can do while seated with your arm:

1. move your arm at the elbow joint up using your bicep
2. move your arm back down using your tricep

Because your muscles are only on and off - even while doing this exercise another neat thing is happening to some degree - cocontration.

When you lower your arm back down, it's not flopping down, because your bicep is co-contracting some.

Ok - another experiment.

1. lock your forearm in a given position (both your biceps and triceps will be somewhat contracted
2. grab your hand with other free arm and try to move your forearm up and down
3. you'll see that your bicep and triceps are INSTANTLY resiting that movement. When a joint is in a co-contracted state that joint will be locked to that position with the mind of the body itself keeping it in place

notes - you can have someone else grab your arm and try to move the joint and you see the same effect. Absolutly instant response of your bicep and triceps to keep the arm elbow joint at the same angle

This is why this is weird:

Your arm is doing this itself. Your brain and the nerve lengths involved can't do this because of the nerve propogation time.

Try this experiment to prove this to yourself:

1. hold your hand out with your thumb opposing your fingers 1/2 inch
2. have someone else hold a dollar bill vertically between your thumb and fingers
3. try to catch that dollar bill when your friend releases it

You can't do it. Your reaction time is too slow. Yet, we can co-contract a joint to lock in a particullar body position and the muscles on either side of the joint will change their output instantly to maintain the joint angle. Weird but beautiful.

Loose Adoption - relaxation:

So, in a co-contracted joint the body is very strong and keeps it's position. It will do this and resist a force far stronger than you could do a bicep or tricep exercise. (like a negative rep in weight training - much much stronger - as a negative rep is really co-contraction resisting a joint movement)

The point is - once co-contraction is achieved to resist forces - using that joint freely is dificult to impossible without releasing the co-contraction effect.

When you relax the body will loosely adopt "neutral".

Here is a self test you can play with for loose adoption. This exercise comes from the realm of singing:

When most untrained singers sing and take a breath before a long phrase they will often breath in strongly and tense up.

Trained singers learn that the body's "loose adoption" relaxed state is in fact a full breath. So, at the end of a long phrase, while maintaining good posture, if you simply relax your lungs will fill with air. What's cool about this is the breath taken in this way goes deeper into the lungs and provides more air than the "forced" taken breath. So, to play with this example of loose adoption, sit with good posture, blow out all your air, pause, then simply relax while retaining your posture. Your lungs will fill up deeply and quite completly.

Skiing and PMTS and co-contraction and relaxation/loose adoption

In PMTS we laterally tip the inside leg - the free leg. Simultaneously we stand - co-contract - the stance leg. When the stance leg is so-cocontracted it's hard to do much with it but let it bear the load. But we have complete freedom of action on our inside free leg. As we flex our downhill ski to begin to setup for our new turn, and we tip that foot the new stance ski will passivly follow the angles of the new free foot. Then we extend and co-contract and create our stance leg for the new turn. We didn't have to worry about keeping that outside leg parallel, as it will passively do this, much like taking a full relaxation breath.

The very first PMTS drill for beginners also focuses on this dichotomy of relaxed and active free foot and stance foot that is first relaxed and follows the inside foot then is cocontracted.

You draw a circle for the student in the snow (oh about 4 feet in diameter). You then have the student use their poles for balance and stand with each foot over the circle. One foot is outside the circle, one foot is inside the circle. You have them lift and tip the inside foot and move it forward a bit and set it down leaving it tipped. You then have them relax the outside leg and let it go where it wants. It will, in this "loose adoption" phase, want to match the angle of tipping of the inside free foot and move up to meet it. They then set that foot down and extend and stand on it (co-contract that outside leg). They'll be in the position to balance and ride out a turn. (not that they are ready for that yet, but these actions stay the same in PMTS thoughtout the progression. Then you have them repeat untill they are all the way around the circle.

Now, in this drill - we are not working on "steering". It's best to de-emphasize any steering idea or component by having the student use many many very small steps. We are reinforcing the actions of tip the inside foot, let the outside foot follow, then stand on the outside foot.

That's my understanding of what HH was meaning when he was talking about co-contraction and loose adpoption.

If I got any of this wrong - Bob Hintermeister who will be at camp this upcoming week can educate me as this is his field (bio-mechanics). Bob is one of the joint developers of the PMTS instructor manual as is a human bio-mechanics expert.

[Biowolf]

Great effort, John. Thanks very much. Biomechanics is not my forte but I thought our outside leg is in excentric contraction and our inside leg in concentric contraction. I wonder if what your are discribing is the same thing or at least related.
I am looking forward to some more input.

[John Mason]

thanks biowolf

I'm just giving my current understanding of what HH may have been alluding to. Hopefully he'll chime in here and say if my paraphrase was what he was trying to communicate or correct things.

When a joint is co-contracted, ie both opposing muscles in tension locking the joints position, both muscles are being used. The stance leg is nearly straight in a turn so your not depending on your quads exerting force to keep that leg strong and supportive but on your joints and skeleton being held in a supportive state.

The fact that PMTS is often a one legged style imitates to some degree walking in that we step with one foot with our weight while the other foot is relaxed and swinging forward with no weight on it. This helps the muscles of the leg recover and is the way they are "designed" to work.

The inside leg, while flexed to remove pressure from it at the end of the turn as it's changing from the stance leg to the new inside free foot, is able to do it's tipping etc, because its relaxed. It's a higher skill level to do this tipping while it still has weight on it (as in the weighted release).

Try this experiment with your arm. Co-contract the arm to lock the arm in a bent position as in the experiment in my prior post. The rotate your wrist while having your arm locked at the elbow in an angle. While co-contracted this is hard to do. Now relax your elbow joint releaing your co-contration and move your wrist around. It's very much easier.

The inside foot, because it's working of the non-supportive leg that is not co-contracting is very easy to laterally tip. It's very difficult to do this with the supporting co-contracting stance leg. That's what's great about the kenetic chain. That stance leg while strong and co-contracted will follow the angles you set up with the easy to manipulate free foot.

Quite simple. This is getting to some of the bio-mechanical reasons why PMTS works so well. (meanwhile others are trying to ski by steering their load bearing co-contracted leg - gosh - now that's hard and works against how your body works and is not needed)

[Harald]

Biowolf

I owe you two answers. First, what do I do to Erich Scholpy?s boots? We must always keep in mind that World Cup boots, (plug boots) are very different from regular, even in line race boots.

WC race boots are extra narrow, Scholpy has big and wide ankle bones and a rigid subtaler joint. He needs room to move his ankle toward the boot wall. I provide this room in a number of ways in the boot. We do a soft boot board modification that we invented and have Patent Pending on. We also do very specific wall modifications to the side of the boot. Since we have done this to Erich, we use it in other racers with the same success. After this work was done Erich won the Bronze at the world championship GS. He won the second run by 2 seconds. He also placed third overall in the GS world cup finals.

We don?t always do it exactly the same way for all skiers, as everyone?s foot has slightly different needs. Erich received new boots from Nordica this fall and he was having trouble. I skied with him and we watched video, we determined he didn?t have enough movement. He had failed to insert the soft boot board we make for him in his new boots. He installed the boot board, I also suggested he change his cuff angle and tip the boot, with slight adjustment, more inward. Two days later, he was sixth in the GS at Beaver Creek.

I have to do this work kind of on the slide with Erich, as the Nordic guys are very protective, he doesn?t like them to know (I hope they don?t read this forum) what we do to his boots.


Co-contraction is fairly easy; it is the activity of the different muscles groups around a joint moving in opposite pulling, one side, loosening the other, actions or directions to stabilize and balance the joint.

Loose adaptation is movement of the body at and with joints, where the antagonistic muscle groups are relaxed and the body moves in a loose and easy manner to its intended position (alignment), almost without conscious intervention by the athlete. An example in skiing would be during the float between turns, the body sets up for the new turn almost without effort falling into place before forces act on it.

[milesb]

Harald, would another example be arms swinging as a person walks?

[Harald Harb]

How about when the ankle and foot swings through from the toe push off, to the heel strick. The ankle and foot adapt to the next landing without you having to think about balancing and absorbing it happens.

[milesb]

Thanks Harald, I get what you are talking about now.

[Biowolf]

Thanks Harald for this important (for me) information. What is interesting is that my bootfitter did the same thing to my boots, punching out the inside so that my foot could move to the inside sidewall. He also punched out the toe box so that my big to was perfectly positioned (straight). The result was dramtaic. (punching is probably not thew best way of doing this ?)
Is there any way a mere mortal can obtain these soft bootboards ?

Also, thanks again John. Sounds as if you came pretty close. Your observation about walking is interesting as well. I read somewhere else that the ankle locks after the foot reaches a certain position after landing.
This position is individually different and should be considered when establishing the forward lean of a boot.