LEARN THE SR STANCE IN 3 EASY STEPS


This post was originally published on October 23, 2016. I have revised the post to clarify that the SR Stance applies to the load phase of a turn that occurs in what is commonly referred to as the bottom of a turn and that the joint angles of the SR Stance are configured by the major muscles in isometric contraction. When external forces cause the muscles to lengthen or stretch this will trigger the myotatic or stretch reflex. Because the myotactic reflex is a spinal reflex it is activated in 1 to 2 thousandths of a second. As such, it is both rapid and powerful.


The SR Stance configures some of the most powerful muscles in the body in a state of isometric contraction so that the powerful myotactic stretch reflex can maintain the angles of the ankle, knee, and hip and keep the CoM of a skier in balance on their outside ski in the most powerful position in the load phase of a turn.

The SR Stance is best learned outside the ski boot in an environment where the feet and legs are free from any influences. One of the benefits of learning an SR Stance outside the ski boot is that, once learned, it provides a reference against which to assess whether a ski boot supports the functional parameters of the skier. If it doesn’t, the SR Stance can be used as a reference to guide equipment modification and establish when and if it meets the functional requirements of the skier.

The SR Stance tensions the pelvis from below and above; below from the balls of the feet through the PA-soleus-gastrocnemius-hamstring muscles to the pelvis and above from the shoulders-latissimus dorsi-trapezius muscles to the pelvis.

The graphic below shows the Achilles Tendon junction with the PA at the heel bone.

pa-ac

The graphic below shows the 3 major muscles of the leg associated with the SR stance.

3-muscles

The Soleus (left image in the above graphic) extends from the back of the heel bone (see previous graphic) to a point just below the knee. It acts in concentric contraction (shortening) to extend or plantarflex the ankle. In EC-SR, the Soleus is under tension in stretch in isometric contraction.

The Soleus is one two muscles that make up the Triceps Surae.

The Gastrocnemius (center image in the above graphic) extends from the back of the heel bone  to a point just above the knee. It acts in concentric contraction (shortening) to flex the knee. In EC-SR, it is under tension in isometric contraction to oppose extension of the knee.

The Hamstrings (right image in the black rectangle in the above graphic) extends from a point just below the knee to the pelvic girdle. It acts in concentric contraction (shortening) to flex the knee. In EC-SR, it is under tension in isometric contraction to oppose extension of the knee.

A number of smaller muscles associated with the SR that will be discussed in future posts.

The graphic below depicts the 3 steps to learning an SR Stance.

er-steps

  1. The first step is to set up a static preload on the shank (shin) of the leg by tensioning the soleus muscle to the point where it goes into isometric contraction and arrests ankle dorsiflexion.

The static preload occurs when the tension in the soleus muscle of the leg simultaneously peaks with the tension in the sheet-like ligament called the plantar aponeurosis (PA). The PA supports the vault of the arch of the foot. The soleus is an extension of the PA. This was discussed in my post ZEPPA-DELTA ANGLE AND THE STRETCH REFLEX.

  • While barefoot, stand erect on a hard, flat, level surface as shown in the left hand figure in the graphics above and below. The weight should be felt more under the heels than under the forefoot.
  • Relax the major muscles in the back of the legs (mainly the hamstrings) and allow the hips to drop and the knees to move forward as shown in the right hand figure in the graphics above (1.) and below.
  • As the knees move forward and the hips drop towards the floor the ankle joint will dorsiflex and the angle the shank forms with the floor and the angle of the knee, will both increase until a point is reached where the shank stops moving forward on its own. Movement of the shank will probably be arrested at a point where a plumb line extending downward from the knee cap ends up slightly ahead of the foot. This is the static preload shank angle. It is the point where the soleus and quadriceps muscles go into isometric contraction.

static-preload

2. From the static preload shank angle, while keeping the spine straight, bend forward slightly at the waist. The angles of the shank (ankles) and knees will decrease as the pelvis moves up and back and the CoM moves forward towards the balls of the feet. This will cause the muscles of the thigh to shift from the Quadriceps to the Hamstrings. Bending at the waist tilts the pelvis forward. As the pelvis tilts forward, it tensions the Hamstrings and Gastrocnemius causing the knee and ankle to extend to a point where extension is arrested by the muscles going into isometric contraction. Tension in the Hamstrings and Gastrocnemius extends the lever arm acting to compress the vault of the arches of the feet from the top of the shank to the pelvis thus increasing the pressure on the balls of the feet through Achilles-PA load transfer.

3. From the position in 2., round the back and shoulders as you bend forward from the waist.

Shldrs-back

Make sure the core is activated and tightened as you round the back and shoulders. Pull the shoulders forward and towards each other as the back is rounded so as to form a bow with the shoulder girdle. Looking down from above, the arms should look like they are hugging a large barrel.

Repeat steps 1 through 3. Pay close attention to the changes in the sensations in your body as you work through each step. If you bounce up and down lightly in the position in Step 3., the angles of the joints in your stance should return to the static preload position between bounces.

With the ski boot and Zeppa-Delta ramp angles configured to enable an SR stance, your ski boots will work for you and with you instead of the other way around.

In my next post, I will go into greater detail on how rounding the shoulders and holding the arms in the correct position optimally activates the muscles associated with the SR stance.

16 comments

  1. hi David
    i think your blogs are great by the way. I understand you have many years of experience and no doubt our passionate about skiing, biomechanics etc. I too am passionate about the sport and would definitely be humbled by your abilities on ski’s as i am far from elite. Like you I have for many years worked with elite skiers and am a little obsessed with biomechanics particularly as it relates to injury. Back pain and injury as you are aware are common amongst skiers and as a sports physiotherapist this is something i regularly manage and give advice on.

    The reason i am reaching out is i am also passionate about this topic and regularly present this to many groups/staff at whistler Blackcomb and from time to time get into discussions regarding your skiers manifesto. So congratulations as you appear to have quite a reach. We have a difference of opinion, however on the skier ready position step #3 with respect to back position and i wonder what your reasoning is to encourage a flexed lower lumbar/back. I am interested to know if you think performance will suffer if people assume a more neutral low back position (neutral lumbar lordosis) as in my experience this significantly reduces the incidence of back pain or improves most who are suffering form it while also improving performance rather than taking away from it.

    To be clear on anatomical neutral spinal position, i often demonstrate to people when standing upright that when you place a ski pole on your back there should be 3 points of contact….back of head, mid shoulders and tailbone/sacrum leaving just less than a hand width in the low back. On bending or hip hinging the same gap in your low back and 3 points of contact should remain indicating appropriate dissociation/movement co-ordination and maintenance of “power position” in a more loaded posture as occurs with a forward trunk position. this neutral low back spinal posture is sometimes mistaken for being anteriorly titled, but its not, as to be anteriorly tilted you must have a hyperextended low back, which is not what i am proposing.

    I often teach the athletic stance (neutral spinal curves with some hip and knee flexion as you also promote) as the starting or default position. As we both know the dynamic nature of skiing requires our spines to move through a fairly full range but when possible i encourage people to default to their neutral lumbar spinal position (power position) or something close to it, rather than staying in a flexed lower lumbar position as this simply disengages most of the deep and superficial truck stabilizers and posterior chain muscles (gluten, hami’s etc) and results in us hanging off ligaments and placing high and potentially damaging loads on our lumbar discs and this threat accumulates when sustained. Many propose that the reason they are doing this is to engage the rectus abdominus (6 pack muscles) which based on basic anatomy only serves to protect us from a punch to the stomach or bring our rib cage to the pelvic, but offers negligible strength or stability across our spine.

    It is therefore in my opinion that we should be in constant adjustments aiming for the less strained and more powerful neutral lumbar lordosis posture much like constant micro adjustments to our centre of mass so we stay balanced. The problem is many don’t know or cannot achieve this position, which leads many to back pain and to booking in for treatment.

    While I still see some high level skiers staying fairly flexed in the low back while skiing, there are many examples of highly skilled moguls and alpine skiers that have a good sense of the neutral power position. Anatomy and biomechanical studies also suggest fairly conclusively that a neutral lordosis creates the necessary length tension relationships through our low back, glutes and hamstrings to best absorb and tolerate high forces or bumps and also puts our joints and soft tissues in the least strained position allowing us to best deal with both expected and unexpected forces.

    I would very much be interested to hear your take on the spinal position encouraged in step 3.

    Mike Conway
    Co-Owner Back in Action Sports Physio
    M Physio Sports, M Physio Manips, M Physio Studies, BSc Kines
    Lead Physio Ski Cross Canada

    1. Hi Mike, welcome to the Skier’s Manifesto. I apologize for the delay in responding to your comment. I have been up to my neck in things.

      As an opening comment, my passion and mission spanning the past 40 years has been and continues to be to advance the principles of skiing as an evidence-based science that displaces the current predoiminance of eminence based positions embraced by popular opinion and influence with little or no support in principles of applied science. I am delighted there is a camp in Whistler who is following my blog. I would be pleased and honoured to meet with yourself and others who are interested in a productive, interact, object dialogue on the issues such as you raise. Minimizing ski injuries is the cornerstone of my efforts.

      “Back pain and injury as you are aware are common amongst skiers and as a sports physiotherapist this is something I regularly manage and give advice on.”

      Perfectly predictable given that it is commonly stated that a ski boot MAXIMISES ENERGY TRANSFER implying that it is somehow a good thing. Newton’s Third Law states that for every action, there will be an equal and opposite action or RE-action. So if the ski boot does indeed MAXIMISE ENERGY TRANSFER to the snow, then the snow maximizes energy through the structures of the boot (bypassing the physiologic processes that normally dissipates shocks from GRF) UP the vertical column to where? The knees and back? Correct. But it is far worse that this as in FAR worse. Proponents of ski boots actually boast indirectly that the boot transfers injurious forces and no one questions this? Rather than speaking to the reasons behind the posture I show in Figure, I will address these issues in a separate post aimed at those with a background in physiology.

      In the meantime, I strongly suggest that you obtain a copy of Barefoot Strong by Dr. Emily Splichal. It will challenge everything you thought you knew. I bought my copy as Kindle book on amazon.ca. The cost? $9.99. The information? Priceless. The best value for money, bar none, that I ever spent in my life and you can quote me on that. Dr. Splichal’s brilliant teachings crystallized many of the things I have been mulling over my mind for decades. I read it none stop. If you do nothing else, buy it and read it again.

  2. Dear Dave,

    Several house keeping things, yes stance is all about balance so I would agree that a powerful stance by definition has to be one that enables SR. that’s sort of a no brainer, one your work suggests has been over looked. Also I referenced two anatomical planes of the body. You point out skiing body movements incorporate in all three. I agree I just used 2 as it was easier for my rhetorical point. When you said this about stance “…rapid balance responses and not as a neboulous look or image” I think ‘rapid’ or dynamic as in ‘constantly changing’ is the key element to describing and understanding stance. Stance is all too often explained as static state of being. That is why I started using the older term form. ‘Form’ I agree is still not as fluid sounding term as required to denote rapidly changing – perhaps use the plural stances or forms is more descriptive (see how it reads below). This is rather fun, thank you.

    I would like to go back to the first two tread posts in this conversational between us. Instead of thinking of one-dimensionally about the skier, is there the possibility of simply methodology differentiate the skier and the natural elements?

    Your first thread post was very helpful to me to begin to differentiate between the actions of the body and the natural forces acting on it. The distinction I am coming up with for the body is what I am calling for “short hand” power and stability are functions of the skeletal, muscular, and neurologic (broadest sense), systems of the body.

    There is something very refreshing about your saying “In skiing, gravity provides the force. An effective ski technique uses muscles to resist forces in a manner that is in phase and consistent with muscles used to mediate the processes of balance.” This seems break with tradition or the way we think about the human being in total control. It congers the idea that the human succumbs to force, resists it and molds force to carve a turn. If you think of a runner applying GRF, gravity is constant and so are all other terrain aspects. Even if gravity is constant in skiing unlike track there are other natural forces such as G force, acceleration and deceleration (in 3 planes or dimensions) that change chaotically due to terrain millisecond by millisecond.

    So it might be useful to conceptually think of those natural forces such as G forces, gravitational pull and acceleration and deceleration as separate, apart and distinct from the actions of the body. The skier is more like a cork in the surf than an assertive controller. Let us being with the body for a closer examination of the subtle differences in my use of words power and stability and your writing and see how they compare to your more analytical approach.

    Additionally skiers unlike sprinters, skiers have to alter stances or forms (note plural) sub-optimally in order to gain stability as they move over undulating terrain. While I think we mean the same thing there is the possibility of confusion. When I read this “…uses muscles to resist forces in a manner that is in phase and consistent with muscles used to mediate the processes of balance” to me it denotes muscular power. That is true muscular strength is used but used to achieve or maintain stability. I am thinking your “mediate the processes of balance” is what I am calling stability in layman’s English. It sort of follows the neurologic system will deploy muscular power to maintain equilibrium stability, the process of SR (stitch reflex) if not the skier crashes.

    I am also using the word power to describe that action that alters skier from which I conceptualize as active and resistant. Examples of active muscular activation could be changing from the lateral lean in the apex of the turn to a neutral position in the transition, plus the activation of the new stance leg (new outside) to initiate the new tern and consequently new lateral lean. To me this signifies the use of muscular power to over power external forces. It may because we are talking about different aspects of the tern but when you say “An effective ski technique uses muscles to resist forces…” I hypothesize skier actually overcomes not resists the G force and gravitational pull by driving the new outside foot down as you describe with the point of pressure being applied to the first metatarsal hopefully also resulting in new inside lean. The resistance to the forces only then takes place as the skier gets higher on edge and skinks into the turn molding and crafting the natural force to control the tern. The art is to instantly change between action and resistance, to conserve energy consumption of both concentric and eccentric contractions by optimizing forms to maximize the efficiency of boot/ski – snow interface.

    Unlike a inanimate mass hurtling over chaotic terrain subjected to external forces, the body changes with its muscular power to create forms (stances) to both remain stable (mediate the processes of balance) and to affect direction of the ski increasing the likelihood of survival. A luxury beginner skiers and inanimate objects don’t have because these are learned neurologic responses.

    In stead of the boot/ski snow interface what you seem to be exploring is the boot – body interface. The body has to be able to millisecond by millisecond detect the physical environment through the scenes, have adequate proprioception, and the precise instantaneous neurologic response in order to survive. When those are present people ski exceedingly well on barrel staves.

    So if I am not mistaken the question you are trying to answer how can the boot accommodate the body so the body can perceive the chaotic environment and act optimally? The boot therefore should neither hinder neurologic perception nor the optimal forms (stances) and should maximize the mechanical advantage of the hard shell. What you are attempting to do is to quantify the answers in a standard or norm which is scientifically sound and reproducible.

    I tried on a pair of new boots the other day and wondered how I could get optimal body forms from them. Looking forward to more essays, thomas

    1. “Instead of the boot/ski snow interface what you seem to be exploring is the boot – body interface. The body has to be able to millisecond by millisecond detect the physical environment through the scenes, have adequate proprioception, and the precise instantaneous neurologic response in order to survive. When those are present people ski exceedingly well on barrel staves.

      “So if I am not mistaken the question you are trying to answer how can the boot accommodate the body so the body can perceive the chaotic environment and act optimally? The boot therefore should neither hinder neurologic perception nor the optimal forms (stances) and should maximize the mechanical advantage of the hard shell. What you are attempting to do is to quantify the answers in a standard or norm which is scientifically sound and reproducible.”

      You are engaged in some serious critical thinking Thomas. This is precisely the kind of high level dialog I have been seeking. You have raised too many issues for me to address in a reply to your comment, so I will ‘touch’ (just barely) on one comment:

      “….the question you are trying to answer how can the boot accommodate the body so the body can perceive the chaotic environment and act optimally”.
      > Precisely. Although I did not have a lucid, comprehensive picture of all the issues when I wrote my notes for US Patent No. 4,534,122 filed on December 1, 1983, I knew that the neural flow associated with postural responses (i.e. the processes of balance) emanated predominantly from the 200,000 or so nerve endings in the feet and mechanoreceptors in the joints and that the structures of the ski boot were introducing out-of-plane foreign forces that were contaminating and degrading the processes of balance. On this aspect alone, the fundamental premise of indiscriminant envelope or, ‘don’t know what it does, don’t care’ on which the contemporary ski boot is predicated should be made it unacceptable, not viewed as the Holy Grail. My efforts spanning the next ten years were focussed on finding a method by which to restrain the foot to an external appliance such as a ski or skate blade that preserved or even enhanced neural flow. That I succeeded in achieving this goal which continues to be ignored by the ski industry even after the associated patents have long since expired making the technology available free for all the world to enjoy, is, in my opinion, a black mark indelibly etched on skiing.

      1. Dear Dave,

        I have enjoyed reading your work and look forward to the next installments. I really did not have and intention to expect you to comment on this last post. Someone else may want to take a stab at it. Hopefully incorporating some of the themes will be helpful to you and to other readers as we move forward in our exploration. So much of what we seem to know about skiing is the result of what has been expedient at the time – often not based on science. This seems to be true of instruction and if I understand you correctly has been true on the manufacturing end as well.

        As I think our dialog demonstrates it is hard to come up with simple terms and concepts to just communicate meaning about skiing form and function let alone the underlying science. Often skiers throw terms about having very technical meaning while others have no meaning at all. Since most of us are not physicists or bio-mechanical specialists it is very easy to misuse or misinterpret technical terms. And layman’s terms are well, nebulous.

        I am guessing you want us to know what pleasure you have had in researching the various aspects body – boot interface. That includes all the avenues you have explored that even the dead ends have been rewarding because you were learning more all the time. Perhaps it has been lonely and in starting this blog you feared more loneliness. That you value learning and the challenge of debating and exploring the engineering required merge the human body-mechanics to the natural forces for optimal management by the skier. So I’m guessing you value greatly the connections you are making here, the European racer who is using your work and others.

        It may sound trite but thank you for asking us all to become just a little more inquisitive, thomas

      2. Very pertinent comments as usual Thomas.
        “So much of what we seem to know about skiing is the result of what has been expedient at the time – often not based on science. This seems to be true of instruction and if I understand you correctly has been true on the manufacturing end as well.”
        > Yes. I have no reason to believe that there was a premediated plot to deceive. Rather it was a case of needing a good (believable) story to justify what was being done. I feel into the ‘need to support the foot’ camp after having what I felt was an epiphany that arose out of overpronation (another invented term) as the cause of running injuries. But being an intensely cursious critical thinker, I began to see that the good stories that the ski industry is based on are the classic house of cards. But once the faulty premises became a source of financial revenue momentum set in that continues to resist and oppose change.

        “As I think our dialog demonstrates it is hard to come up with simple terms and concepts to just communicate meaning about skiing form and function let alone the underlying science. Often skiers throw terms about having very (limited?) technical meaning while others have no meaning at all. Since most of us are not physicists or bio-mechanical specialists it is very easy to misuse or misinterpret technical terms. And layman’s terms are well, nebulous.”
        > It seems to be a typical human behaviour to invent a nebulous term to explain away a situation or create an illusion of knowledge where there is none. And most lack the courage or motivation to challenge obviously flawed statements choosing instead to simply parrot them.

        “So I’m guessing you value greatly the connections you are making here, the European racer who is using your work and others.”
        > Yes, I do because I constantly push my limits so I can expand my knowledge.

  3. Hi David
    I am getting ready to experiment with reducing my ramp to less than 3 degrees. I have measured my zeppa angles at 5.1Salomon Xmax and 5.5 degrees Fischer RC140. Both are 27.5 mondo. My bindings have 0 degrees of delta. I am looking at 8 ish mm of lift under the front binding to reduce the ramp angle below 3 degrees. I have two questions before I proceed.
    1. Is 8 mm of lift uncommon?
    2. Should I try for the same ramp angle on my DH SG GS and Sl skis or does each require individual assesment? I have read on Epic that DH and SG skis benefit from more than 3 degrees of ramp angle.
    Regards
    Bill Sule

    1. Hi William,
      It is important to separate zeppa (boot board) angle from delta (binding angle). If zeppa is excessive, correcting it by raising the toe of a binding will have the effect of reducing the forward lean of the boot. For this reason, the standard I use is to start with about 2.35 to 2.4 degrees of zeppa angle and 0.2 degrees of delta and keep delta the same for all bindings. The zeppa numbers for your Salomon Xmax (5.1) and Fischer RC140 are, unfortunately, typical of what I have seen with some race boots almost at the other end of the scale with zeppa angles in the low 2s.

      1. Is 8 mm of lift uncommon?
      > Yes, or even more. Many recreational setups (zeppa + delta) are between 6 and 10 degrees.

      2. Should I try for the same ramp angle on my DH SG GS and Sl skis or does each require individual assesment? I have read on Epic that DH and SG skis benefit from more than 3 degrees of ramp angle.
      > That is what I do. I hear stories of racers even at the WC level having different pairs of boots for every discipline. Maybe I am missing something, but I fail to see any valid reason for this. It has been known for over a century that elevating the heel relative to the forefoot, more than a small amount, will prevent the Stretch Reflex. Until a skier or racer has solidified an SR stance and a boot has been configured to accommodate it, the most probable explanation for the nonsense of different ramp angles is that the boot is inhibiting and otherwise limiting skier/racer function. The next time someone tells you that DH and SG skis benefit from more than 3 degrees of ramp angle, ask them to provide a detailed explaination based on principles of functional anatomy how this works. Hint, “Just because”, does not work.

      With a 2.4 + 0.2 = 2.6 standard, I have the skier/racer ski in the 2.6 ramp angle for a few runs then add a 1 mm shim under the heel of one insole (which are akways heated and pressed flat) and compare the feel of that boot to the other boot with no shim. One mm is around 0.2 degrees give or take a bit. One mm thick forefoot shims can be tried to test less ramp. While shims introduce a small amount of what is called ‘toe spring’, I have not found it significant. In cases where the startibng zeppa was in order of 2.2 degrees, it is amazing how much better a skier/racer will ski with 1 mm shim added under the heel. It instantly shows up in video,

  4. Dear Dave,

    I been mulling the 3 steps to learning an SR Stance as I have been curious for a long time to explain stance in a way learners can apply it. Your detailed work here in bare feet shows the advantages of bare feet over doing it with skies on snow.

    I’m still working through the methodology of your three easy steps. The forth figure or stance number 3 in your drawing crystallizes some contradictions for me. In track and field sprinting if I am not mistaken the power of the foot driving down from a near perfectly stacked skeletal frame is what gives one runner an advantage over someone who has the posture of frame #3. So in skiing we compromise power for stability or postures that allow for vertical survival in chaotic terrain and rapidly changing conditions. Successful races optimally maximize both power and stability relative to each other.

    So I wanted to check with you my understanding when you say “bend forward slightly at the waist” the meaning is to keep the pelvis and lumbar spine aligned in the Coronal or frontal (for aft) plane. The leaning occurs at the femoral ball and socket joint or hip. Therefore the pelvis and lumbar spine do not hinge but lean together as a board would. This is the trade of between power and skier stability that a sprinter does not have to compensate for. Yet by keeping the pelvis and lumbar spine in anatomical alignment both power and stability are maximized relative to each other even with the forward lean. Did I get that the way you wanted it known?

    I am also wondering about the rounding of the back. There is no doubt that skiers do this through the turn; however the body may adjust to a more straight (vertical) alignment in the turn transition. This is where power is needed to what you and Mikaela Shiffrin have described as “getting over it”. In looking at some rather rudimentary stopped frame of her at the transition I see a straight back from pelvis to cranium. Then in the turn she incorporates the posture you describe frame #3. It would seem her brain is maximizing the utility of various stances. The way martial artists do.

    Finally there are ways to round the back which may not be apparent at first glance but possibly simply compromise stability and power. For example the head ways around 10-11 pounds (4.5 to 5 kg plus helmet) so that an iphone posture (head jutted forward) is burdensome to the body’s frame all the way down to the feet. The brain may want to be crunch the torso, “rounded forward” to deal the G and other forces of a 60 MPH turn. The question becomes how best is the head supported throughout this process? It stands to reason both optimal stacking and anatomically defensive position (rounding the back forward, crunching) can be achieved by arching in the lower thoracic spine keeping the sternum shoved back and up so that upper thoracic spine is inline with the cervical spine i.e. straightish under, supporting the head. This avoids the turtlelitis (head jutted forward) associated with an iphone posture.

    It seems complicated when I am still learning more about feet and boots.

    You seem to be heading to presenting a much more holistic approach of describing how the foot and body move together throughout the turn for optimal power and stability. Or put another way, finding and practicing the SR Stance introduces the brain to ways of maximizing power and stability while maintaining equilibrium through out the turn.

    I am looking forward to seeing you develop this further and enjoy the learning and conversation here, thomas

    1. Thomas, your comments are exactly what I was looking for when I started this blog.

      As an opening statement, I intentionally put myself in a position where I was forced to think and especially to drill down into issues and acquire an understanding at the level of basic principles. The impetus was nebulous statement such as “get forward”, “get over it”, “get on your skis” that seem to make up the predominate narrative in skiing. It was also apparent to me that unwarranted assumptions and conclusions were being made because there was no standard to assess skiers and racers against. For example, it may seem reasonable to assume that a racer is performing to their full potential if they are consistently on the podium. I believe that such assumptions can seriously limit potential.

      I believe the central issue that defines performance in skiing is stance. So I set out to disect it and provide a rational for every component that can be universally applied to every skier racer assuming they do not have pathologies that preclude this.

      Now to your comments

      The forth figure or stance number 3 in your drawing crystallizes some contradictions for me. In track and field sprinting if I am not mistaken the power of the foot driving down from a near perfectly stacked skeletal frame is what gives one runner an advantage over someone who has the posture of frame #3. So in skiing we compromise power for stability or postures that allow for vertical survival in chaotic terrain and rapidly changing conditions. Successful races optimally maximize both power and stability relative to each other.
      > First, let’s view the activity of skiing in the challenge of balancing on a platform moving over undulating terrain in constantly changing 3 dimensional forces. Put another way, the stack of ski equipment between the soles of a skiers feet and the snow is complex perturbation device that tests the ability to maintain equilbrium. The ability to align joints and major segments of the body through the stack of equipment so as to align applied and resultant forces with GRF from the snow is the issue, not the physical of force. In skiing, gravity provides the force. An effective ski technique uses muscles to resist forces in a manner that is in phase and consistent with muscles used to mediate the processes of balance. Using the leg(s) to hold skis on edge does not meet this criteria.

      I will speak to the other issues you raise in my next post.

      1. Dear Dave,

        Glad to hear of your enjoyment. We are indebted to you for your efforts.

        I have read over both my post and your response several times. Pondering it and trying to understand the meaning through a mix of terms, descriptions and expressions. While part of what I talked about you wanted to cover in future essays there are some things which might be useful to explore right now. In reflecting on our two communications I come up with is a muddle, which is surprising because I think we are saying the same thing if not very similar. So I would like to compare and contrast letting you know what I am hearing from you as well as explaining a bit more precisely what it is I wanted you to hear.

        But before we do that I wanted to check with about, “I believe the central issue that defines performance in skiing is stance” After this you go through a rather complete dissertation how body is acted on and how the body may act in relation to the forces due to chaotic terrain. I was rather stumped by the penultimate sentence as it seems to come out of no where – unrelated. What I think you want us to know by “Using the leg(s) to hold skis on edge does not meet this criteria.” is stance trumps ‘skis holding’. Skies on snow, skies bending, skies arching, and skies on edge is in some ways the holy grail of instruction. What I think you are saying is function follows form. That is if form is adequate the function of the ski will follow. Ergo the better the form the better the application is of the ski to the snow.

        This actually makes lot of historic sense. People were skiing exceptionally well before stiff boots. The skiers in the 1931 film “Der weisse Rausch” or The White Ecstasy are generally fantastic skiers anchored by Hannes Schneider. The skis then were finely crafted state of the art but by today’s standards were barrel staves. Thus as I think you have pointed out many times in the past it’s not the boots or skies that make skiers it is something else.

        So am I hearing from you that stance AKA form is really the determining factor to survival on down hill skies. That the boot/ski – snow interface is the result of form not the cause of it? So in order to understand the boot/ski – snow interface we must understand the body mechanics of skiing form (stance).

        I wanted to get this out of the way before moving back to the items I mentioned in the second paragraph, thomas

      2. While part of what I talked about you wanted to cover in future essays there are some things which might be useful to explore right now.
        > Agree.

        In reflecting on our two communications I come up with is a muddle, which is surprising because I think we are saying the same thing if not very similar. So I would like to compare and contrast letting you know what I am hearing from you as well as explaining a bit more precisely what it is I wanted you to hear.

        But before we do that I wanted to check with about, “I believe the central issue that defines performance in skiing is stance.”
        > Specifically, stance that enables SR.

        After this, you go through a rather complete dissertation how the body is acted on (by external forces) and how the body may act in relation to the forces due to chaotic terrain. I was rather stumped by the penultimate sentence as it seems to come out of no where – unrelated.

        What I think you want us to know by “Using the leg(s) to hold skis on edge does not meet this criteria.” is stance trumps ‘skis holding’. Skis on snow, skis bending, skis arching, and skis on edge is in some ways the holy grail of instruction. What I think you are saying is function follows form. That is if form is adequate the function of the ski will follow. Ergo the better the form the better the application is of the ski to the snow.
        > Exactly. In my post INNATE BALANCE I explain that skiing must be a reflex activity as opposed to a consciously mediated activity. Due the rapid processing of information required even at recreational skiing speeds, the latter is a case of too little, five turns too late.

        This actually makes lot of historic sense. People were skiing exceptionally well before stiff boots. The skiers in the 1931 film “Der weisse Rausch” or The White Ecstasy are generally fantastic skiers anchored by Hannes Schneider. The skis then were finely crafted state of the art but by today’s standards were barrel staves. Thus as I think you have pointed out many times in the past it’s not the boots or skis that makes skiers, it is something else.
        > Exactly.

        So am I hearing from you that stance, AKA form, is really the determining factor to survival on down hill skis (and finese). That the boot/ski – snow interface is the result of form not the cause of it?
        > Exactly.

        So in order to understand the boot/ski – snow interface we must understand the body mechanics of skiing form (stance).
        > Exactly. Understand and be able to reproduce stance on an individual basis. We need to think of stance as the end objective of a specific configuration of body segments, joints and muscles that produces a specific effect, automatic, rapid balance responses and not as a neboulous look or image.

        Inspired by your excellent dialog, I am working to develop a higher level of expertise with the illustration programs I use such as Poser and Visible Body – Muscle Premium. I hope to have new posts up in the next day or two.

  5. Dear David
    In your earlier post on SR you mention as the final step to complete the stance “Move forward in the hips until you feel good pressure under the balls of your feet.” You have not repeated this advice in this post. Stance 3 appears to have his centre of mass quite far back, looks like he is in the back seat. Am I misunderstanding the final stance?
    I am really looking forward to your post on boot stiffness; at the moment I dont understand why stiffness is so important so I am clearly not understanding all that I need to.
    I have modified my boot boards by adding material to the front to flatten them and reduce their angle, I look forward to trying them out on snow at Christmas and hope to have understood all the key info in your posts by then.

    1. “Move forward in the hips until you feel good pressure under the balls of your feet.” You have not repeated this advice in this post.

      > Here is what I said, “Bending at the waist tilts the pelvis forward. As the pelvis tilts forward, it stretches the Hamstrings and Gastrocnemius causing the knee and ankle to extend. Tension in the Hamstrings and Gastrocnemius extends the lever arm acting to compress the arches of the feet from the top of the shank to the pelvis thus increasing the pressure on the balls of the feet through Achilles-PA load transfer”. Fine tuning is coming in future posts.

      “Stance 3 appears to have his centre of mass quite far back, looks like he is in the back seat. Am I misunderstanding the final stance?”

      > Despite universal recognition of a strong stance as the foundation of balance and solid technique, the issues I am discussing don’t even appear to be on the radar screen. Here’s the stark reality –

      “Skis have been used for 2500 years to permit the motion of people living in countries where the snow was present for several months a year. Despite the large market of ski equipment, not many scientific papers have been published on this subject in the past. Moreover, most of the scientific work regarding the development of new materials and designs for ski-boots has been published as patents.” – Materials, Designs and Standards Used in Ski-Boots for Alpine Skiing – 21 October 2013: Martino Colonna, Marco Nicotra and Matteo Moncalero.

      My read of the above statement based on 4 decades of personal experience is that the predominant area of activity in the ski industry is finding ways to make money from skiing by commercializing products and commidifying services such as ski lessons based on the industrial model. Put another way, the majority are taking from the ski industry and skiers and few are giving to the sport.

      “Stance 3 appears to have his centre of mass quite far back, looks like he is in the back seat. Am I misunderstanding the final stance?”

      > The weight of the body, as expressed by CoM, is the weighted average of the body parts and can fall outside the body. You have to look at and consider the entire body. The best instrument the human has for assessing position of CoM in relation to the feet is in the 200,000 nerve endings in the feet, that is assuming the foot is not tightly constrained within the structures of a ski boot in which case, all bets are off.

      “I dont understand why stiffness is so important”.

      > The flex rating of a ski boot is really the deformation rating. Find and read this article published in the Journal of Sports Science and Medicine in 2005: AN INNOVATIVE SKI-BOOT: DESIGN, NUMERICAL SIMULATIONS AND TESTING – Stefano Corazza 􀀍 and Claudio Cobelli and you will know why I want a stiff boot. I will get to this in a future post.

  6. Hello David, You have been posting incredibly detailed information in so many posts. You passion for promoting skiing stance and alignment has not diminished in all these years.
    You mentioned patenting boots, but it never came to fruition. You seem to intimate that shorter leather boots were preferable to taller plastic boots. That the arch of the foot must be free to work. That the drop must be minimal, the height of the heel down to the ball of the foot. I am wondering in the Apex ski boots are approaching what this you are looking for? I am a PSIA ski instructor looking for new boots this year. With each of your new posts, I hold my breath thinking you will finally recommend some boot that approaches your ideal! From what you have described I want something approaching at ramp angle of 2.7 degrees! Thank you.

    1. Hi Roland, welcome to the Skier’s Manifesto. I started the blog in 2013 because after several decades there were still a lot of issues that were not completely clear. I decided to immerse myself in these issues because I had just written a patent for a revolutionary footwear technology which continues to proceed through the patent process unopposed which means the concepts disclosed in the patent have never been articulated before. The inventive process stirred up the bits and pieces of the ski technique in my head that I had never addressed to my satisfaction. About two years ago, I started working with a small group of skiers, ski pros and racers. For the past 2.5 years, I have been working with a racer in Europe on almost a daily basis. This includes analyzing videos from every training session and race. I have learned more from this intense level of interaction than I have learned in several decades. I view every interaction such as yours as an opportunity to learn and advance my knowledge.

      To respond to the issues you raise.

      You mentioned patenting boots, but it never came to fruition.
      > Correct. One reason was that materials with the right qualities and the required manufacturing methods simply did not exist. They do today and a cycling shoe using a technology of which I am the lead inventor appears to be on the cusp of reality.

      You seem to intimate that shorter leather boots were preferable to taller plastic boots.
      > No.

      That the arch of the foot must be free to work.
      > Absolutely true.

      That the drop must be minimal, the height of the heel down to the ball of the foot.
      > Absolutely true. Although this is an area that should be researched, through recent ‘blind testing’ with the racer I am working, with different combinations of Boot Board Ramp (Zeppa) and Binding Ramp (Delta) angles, demonstrated that a Zeppa of 2.4 degrees in combination with a Delta of 0.2 degrees (total = 2.6 degrees) seemed to give the best results in terms of the ability to load the shovel of the outside ski in the bottom of the turn and create a Comma Hook turn where the shovel locks up the outside edge and rapidly hooks into an arc across the skier’s line. This closes the kinetic chain allowing the racer to apply aggressive rotation of the outside leg that is translated through the subtalar joint in the ankle into rotation of the outside ski about its long axis; the racer rotates the ski onto an extreme edge angle in a manner that increases edge hold. I am just analyzing Gut’s Gute Moves from Solden. She seems to be using this technique. It’s not magic. It’s just mechanics and physics.

      I am wondering in the Apex ski boots are approaching what this you are looking for?
      > I am not familiar with the Apex boot.

      I am a PSIA ski instructor looking for new boots this year. With each of your new posts, I hold my breath thinking you will finally recommend some boot that approaches your ideal!
      From what you have described I want something approaching at ramp angle of 2.7 degrees!
      > Or slightly less.
      I mainly work with Head and Atomic because that is what most of the skiers, ski pros and racers who come to me are using. Last season, I worked with local Whistler-Blackcomb Ski Pro, Matt Williams. Matt is a big boned, big guy at 225 lbs. I warned him, but he tried a Head 130 anyway. It was way too soft. So he went to a stiff Atomic race stock boot. It took all season and 3 or 4 liners to get them so Matt’s feet could function. Race boots are especially bad because the plastic is thicker = less volume and width; a nightmare for most skiers.

      I will be posting on Head and Atomic boot modifications; the good, bad and the ugly, as I work out solutions. The one boot I am considering for myself is a Head RD. For reasons I will explain, I want the stiffest boot I can get.

      If you have any questions, please post them in comments and I will do my best to respond.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.