Skier Balance posts

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.

WHY TRYING TO COPY HIRSCHER AND SHIFFRIN’S MOVES DOESN’T WORK – PART 4

A central premise in skiing, especially in ski teaching and coaching, is that skiers and racers can learn to ski like the best by observing and copying them. Hence, articles and videos that talk in nebulous terms about good balance, an athletic stance, pressure control, steering, edging, extension, separation etc. as elements that, when blended together, will enable skiers and racers to ski like the Hirschers and Shiffrins of the world. If a racer who has undergone training in the system is not competitive or worse, suddenly becomes uncompetitive, the racer is typically blamed for not being strong enough or not pushing themselves hard enough or not taking enough risk or some other factor. In the end, the responsibility for lacklustre performance is conveniently assigned to the racer.

Ski boots are rarely considered a factor. So long as the boots are comfortable that is the only thing that matters. To suggest otherwise is to blame the equipment. This flies in the face of my experience. But until the skate study (1.) I had no reliable way of measuring and thus comparing performance.

The two pressure studies done in 1998 by the University of Ottawa with elite ski instructors provided an opportunity to compare the results of the studies to those of the 2012 skate study that I modified skates for. This study was also done by the University of Ottawa. Of the three studies:

  • One 1998 skier pressure study used three highly skilled ski instructors (CSIA level IV)
  • One 1998 skier pressure study used six internationally certified Canadian ski instructors.
  • The 2012 skate study used five competitive skaters.

The 1998 study with the six internationally certified Canadian ski instructors provided Peak Force data that I could use to compare to the Peak Force data obtained from the 2012 skate study.

As I pointed out in my previous posts, skating and skiing are similar in that they both depend on the ability of the participant’s neuromotor system to create a foundation of dynamic stability across the skate blade or the inside edge of the outside ski prior to being able to effectively apply force to the ice blade or ski edge. The existence of dynamic stability across the skate blade or inside edge of the outside ski enables the neuromotor system to regulate fore-aft stability in what is typically referred to as skater or skier balance.

Peak Force

Peak Force is the highest force applied in an Impulse Force

In the skate study skaters performed forward skating sprint starts in each skate (OS and NS) for a total of 6 trials each. As would be expected with competitive skaters Dynamic Stability as represented by Peak Force was very close among the skaters in their Own Skates as shown in the graphic below.

But when the highest and lowest Peak Forces of the competitive skaters were compared to the highest and lowest Peak Force of the internationally certified Canadian ski instructors the difference was much greater; approximately 125% for the skaters and 300% for the ski instructors. The researchers noted this significant variance and suggested equipment could have been a factor. But that aspect was not investigated.

Peak Force Improvement

It would seem logical to assign sole responsibility for such marked differences to inferior muscle strength or improper training. Muscle strength and training are definitely important factors. But their contribution to overall performance is dependent on the ability of a competitor to create dynamic stability and quickly acquire a position from which they can effectively apply force to a skate blade or edges of a ski. These factors, in turn, are dependent on a functional environment in the footwear for the physiogic function of the lower limb.

As shown in the graphic below, when the same skaters switched from their Own Skates (OS) to the skates I prepared (NS) there was an immediate and statistically significant improvement in mean Peak Force of approximately 190%. Even more significant is the fact that the Peak Force of skater number 4 (the lowest of the four skaters) increased by approximately 252% changing the skater’s ranking from #4 to #1.

Impulse Force Improvement

An Impulse Force is a high force of short duration that causes a change in momentum.

When the skaters switched from their Own Skates (OS) to the New Skates (NS) there was an immediate mean increase in Impulse Force of approximately 216% as shown in the graphic below. Even more significant, the Impulse Force of skater number 4 (the lowest of the four skaters in their Own Skates) increased by approximately 276% raising skater number 4 to almost the same level as skater number 3. Meanwhile, an increase in Impulse Force of approximately 224% raised skater number 2 to almost the same level as skater number 1. In other words, the New Skate was literally a game changer that resulted in a leveler playing field for the four competitive skaters.

Center of Force (CoF) Variance: Where Races are Really Won

The most significant effect of the New Skate (NS) was on what is called Center of Force (CoF) Variance. Center of Force Variance is the amount of forward movement of the Center of Force within a fixed unit of time to the position on a skate blade or ski edge where force can effectively be applied.

The graphic below shows the Center of Force Variance of the four competitive skaters in their own skates (OS).

The graphic below shows the Center of Force Variance of the four competitive skaters in their Own Skates (OS) compared to the Center of Force Variance in the new skates (NS). When the skaters switched from their Own Skates (OS) to the New Skates (NS) there was an immediate mean increase in CoF Variance of approximately 172% as shown in the graphic below. Skater number 4 experienced the largest increase in CoF Variance (approximately 241%) that changed the ranking from #3 to #1.

An increase in the variance of CoF results in increased control during the stance phase of forward skating.

The graphic below shows what would happen if only skater number four were provided with New Skates (NS) while the other 3 competitive skaters continued to use their Own Skates (OS). Think of the red dashed line at 1.20 as the finish line of the CoF Variance race. It should obvious who will win and who will have the advantage at every turn.

The Score for Skater Four

Skater number four experienced the following improvements in the New Skates (NS) over their Own Skates (OS)

  • Peak Force – 252%
  • Impulse – 276%
  • CoF Variance – 241%
  • Mean improvement – 256%

The improvement in the three metrics was immediate and, based on my experience with skiers and racers, probably immediately reversible simply by having the competitive skaters revert to their Own Skate (OS) format.

Few forms of athletics place as high demands on the footwear used in their performance as alpine skiing. It (the ski boot) functions as a connecting link between the binding and the body and performs a series of difficult complex tasks. (2.)

To paraphrase Dr. Emily Splichal:

A skier is only as strong as they are dynamically stable.

In my next post, I will discuss the implications of the skate study and associated performance technology and metrics for the future of skiing, especially ski racing.


  1. A Novel Protocol for Assessing Skating Performance in Ice Hockey – Kendall M, Zanetti K, & Hoshizaki TB – School of Human Kinetics, University of Ottawa. Ottawa, Canada
  2. Ski-Specific Injuries and Overload Problems – Orthopedic Design of the Ski Boot –  Dr. med. H.W. Bar, Orthopedics-Sportsmedicine, member of GOTS, Murnau, West Germany

WHY TRYING TO COPY HIRSCHER AND SHIFFRIN’S MOVES DOESN’T WORK – PART 2

In previous posts I discussed the two studies (1, 2) done by the University of Ottawa in 1998 that analyzed pressure under the feet of elite alpine ski instructors

The pressure data from the study that used 6 elite alpine ski instructors found maximal (peak) force ranged from a high of 1454 Newtons to a low of 522 Newtons. The graph below compares the peak force seen in pressure data captured from the 4 competitive skaters in their own skates from my last post to the highest and lowest peak force seen in pressure data captured from the 6 elite alpine ski instructors used in the 1998 University of Ottawa study.

In consideration of the fact that the researchers commented that force-time histories revealed that forces of up to 3 times body weight can be attained during high performance recreational skiing it is interesting that the peak force of one of the 6 elite alpine ski instructors in the study was less than the lowest peak force of one of the 4 competitive skaters in the 2012 University of Ottawa study while the highest peak force of one of the 6 elite alpine ski instructors in the 1998 study was almost twice the highest peak force of one of the 4 competitive skaters in the 2012 University of Ottawa study.

A significant challenge in attempting to conduct foot pressure studies with alpine skiers is the variability of the slope and environmental and piste conditions. Test conditions and variables, especially ice, can be tightly controlled in the conditioned environment of an indoor skating rink.

Although the studies did not provide pressure data that compared peak and average pressures for different ski instructors, the peak forces from one study reached up to 30 newtons per square centimetre.

In the spring of 2012 I was asked to modify a number of pairs of the same brand and model of a hockey skate for use in a study that would compare metrics derived from pressure data captured from a competitive skater’s own skates to the same metrics from data acquired  from skates I had modified. I saw this as an opportunity to document the effect of modifications made to hockey skates based on the principles of neurobiomechanics described in my patents and this blog. When I speculated that the metrics derived from the pressure data might show improvements as high as 10% (i.e. 110%) I was told that the study was unlikely to result in more than a single digit improvement of approximately 2% or 3%.

I modified the pairs of skates in the shop in the garage of my home near Vancouver. The modifications were general in nature and made without the benefit of data on the feet of the test subjects. No modifications were made after I shipped the hockey skates to the University of Ottawa. I was not involved in the design of the study protocol or the actual study. I was hopeful that the study would produce meaningful results because it would have implications that could be extrapolated to alpine skiing.

The graph below shows the highest peak force in Newtons recorded for each of the 4 competitive skaters in their own hockey skates (blue = OS) and in the hockey skates that I modified (red = NS). The improvement was immediate with little or no run in period in which to adapt. The percentage improvement for each skater is shown at the top of each bar.

The mean (i.e. average) improvement was approximately 190%. The only factor that improvements of this magnitude could be attributed to is improved dynamic stability resulting from an improved functional environment in the skate for the foot and leg of the user.

……. to be continued in Part 3.


  1.  ANALYSIS OF THE DISTRIBUTION OF PRESSURES UNDER THE FEET OF ELITE ALPINE SKI INSTRUCTORS – Dany Lafontaine, M.Sc.1,2,3, Mario Lamontagne, Ph.D., Daniel Dupuis, M.Sc.1,2, Binta Diallo, B.Sc.: Faculty of Health Sciences1, School of Human Kinetics, Department of Cellular and Molecular Medicine, Anatomy program, University of Ottawa, Ottawa, Ontario, Canada.
  2. ANALYSIS OF THE DISTRIBUTION OF PRESSURE UNDER THE FEET OF ELITE ALPINE SKI INSTRUCTORS – Dany Lafontaine, Mario Lamontagne, Daniel Dupuis, Binta Diallo, University of Ottawa, Ottawa, Ontario, Canada

IS SHIFFRIN ON THE LEVEL?

By on the level, I am suggesting that Shiffrin may have a much lower zeppa-delta ramp angle than her competition.

Here are some screen shots from the March 18, 2018 Are Slalom where Shiffrin won by  1.58 seconds. She is on and off her edges in milliseconds as she just seems to pop from turn to turn – Total Domination From Shiffrin (1.)

Compare the angles of Shiffrin’s ankle, knee and hip in the photo below to those of her competition in the second and third photos below.

Notice how extended Shiffrin’s lower body is as she exits the rise line and enters the bottom of the turn in the photo below from a training session earlier in the year.

Extended in the Are Slalom.

Out of the start her knees and ankles are almost straight!

In my next post I will explain what I think is happening and why.


  1. https://youtu.be/gQu-LkyfsRQ?list=PLo6mlcgIm9mzWPBpeXnH2CpFOXrWhBiEB

ZEPPA-DELTA ANGLE EXTENDER

The problem associated with measuring boot board (zeppa) and/or binding (delta) ramp angle as individual components is that the resulting angle may not accurately reflect the actual angle between the plane of the base of the upper surface of the boot board and the base of the ski in the boot/binding/ski system. Boot boards of the same zeppa angle may not necessarily have the same zeppa angle with the base of the boot shell due to design and/or manufacturing variances.

A level inserted into a ski boot shell with the boot board in place can be difficult to read. With the liner in place, this is not a viable option. A better option is to extend the angle of the boot board up above the top of the shaft of the boot so it can be accurately and easily read.

A simple device for this purpose can be made for about $25 with basic hand tools and a few screws using 2 – 8 in (20 cm) x 12 in (30 cm) x 1/8 in (3 mm) thick steel carpenter’s squares.

Place the long arms of the squares over each other as shown in the photo below and clamp them securely together. Two-sided tape can be used to help secure the alignment. Then drill a hole  at one point on the vertical leg and screw the 2 squares together.

Check the parallelness of the 2 opposite arms on a level surface with a digital level. If good, secure the 2 levels together with a second screw. Then affix a section of 3/4 in (2 cm) x 3/4 in (2 cm) square or L-bar bar on the top of the extender to rest the level on.

To use the extender, place a boot shell on a hard, flat, level surface. If the surface is not level it should be leveled before the extender is used.

The photo below shows the extender being used to measure the zeppa angle of an old Salomon SX-90 shell. I didn’t have the electronic level for the photo. So I used a small torpedo level.

Insert the lower arm of the device into the shell as shown in the right hand image and place the lower arm firmly on the boot board. Place the level on the top arm and read the angle.

The photo below shows the same process as above. But in this example, the liner is in place. If an insole is in the liner, it should be flat with no arch form. I highlighted the square bar with pink to make it easily visible.

A check of the zeppa-delta angle of the boot-binding-ski system can be done by mounting the boot in the binding of the ski that is part of the system and clamping the ski to a flat surface with sufficient force to ensure the camber is removed and the running surface of the base is in full contact with the supporting surface. A strap wrapped over the front of the boot shell and under and around the supporting surface then tensioned will help ensure that the toe plate of the binding is loaded.

The Zeppa-Delta Angle Extender provides the user with a fast accurate way to know their total number. What’s yours?

 

WHY STANCE TRAINING IS ESSENTIAL

When readers click on my blog address at skimoves.me, analytics give me a hierarchy of the countries with the most views and the most popular posts in ascending order. This helps me identify which content resonates most strongly with viewers and which content draws a blank.

As I write this post, the top five countries are the US followed by Croatia, the United Kingdom, Slovakia and France.

The most viewed post today is THE SHOCKING TRUTH ABOUT POWER STRAPS; far and away the most popular post I have published to date. But the most important posts by far that I have ever written, A DEVICE TO DETERMINE OPTIMAL PERSONAL RAMP ANGLE and STANCE MUSCLE TENSIONING SEQUENCE EXERCISE barely sputtered in comparison. This strongly suggests that far from just some small gaps in the knowledge base skiing is founded on, massive craters exist.

Arguably the most important aspect of skiing is a strong stance. Any variance in the fore-aft angle of  the plane of support under the feet and the plane of the base of the ski has significant impact on stance. Yet these subjects are barely blips on the Doppler Radar of the ski industry.

Since I started the dynamic ramp angle assessment project a few weeks ago I have found that when asked to do so, it is rare for a skier of any ability to be able to assume a strong ski stance in an off the ski hill environment. Even when a skier  skis with a relatively strong stance, they seem to lack a sense of what a strong stance feels like. Because of this, they lack the ability to consciously replicate a strong stance. If asked to do so, they would be unable to coach a skier in the sequence of events that I described in my last post

In the dynamic ramp angle assessment project, I  have also observed that skiers with with a boot/binding ramp angle greater than 2.8 degrees appear to have become accustomed to the associated unstable, dysfunctional feeling and identify with it as ‘normal’. Before I can test them, I have to spend time coaching them into the correct stance because it feels unnatural to them.

When I go back and forth between a strong functional stance on a flat, hard level surface to a stance on the dynamic ramp angle device set to an angle of 4 degrees, I can get close to the same angles of ankle, knee and hip. But when I do, I feel strong tension, stiffness and even pain in my mid to lower back which is  common in some skiers and even racers.

Based on results to date with the dynamic ramp angle device, it appears as if strong skiers ski best with ramp angles close to zero. But depending on their sense of balance and athletic ability, they may have a wide range in which they sense little difference on the effect of ramp angle until they approach the upper limit of stability. While they may be able to ski well with a ramp angle close to the maximum limit of stability, ramp angles much above 1.2 to 1.5 degrees may not offer any benefits. This can only be tested on skis where balance is tested by dynamic forces which cannot be replicated in a static setting.

Issues affecting skier stance were discussed in detail in my post, THE SHOCKING TRUTH ABOUT POWER STRAPS. Here are the excerpts I posted from the chapter on The Ski Boot in the book, The Shoe in Sport (1989), published in German in 1987 as Der Schuh Im Sport– ISNB 0-8151-7814-X

“If flexion resistance stays the same over the entire range of flexion of the ski boot, the resulting flexion on the tibia will be decreased. With respect to the safety of the knee, however, this is a very poor solution. The increasing stiffness of the flexion joint of the boot decreases the ability of the ankle to compensate for the load and places the entire load on the knee”. – Biomechanical Considerations of the Ski Boot (Alpine) – Dr. E. Stussi,  Member of GOTS – Chief of Biomechanical Laboratory ETH, Zurich, Switzerland

“The shaft of the boot should provide the leg with good support, but not with great resistance for about two thirds of the possible arc, i.e., (14 degrees) 20 to 22 degrees. Up to that point, the normal, physiologic function of the ankle should not be impeded”.

“Previous misconceptions concerning its role in absorbing energy must be replaced by the realization that shaft pressure generates impulses affecting the motion patterns of the upper body, which in turn profoundly affect acceleration and balance.

“When the lateral stability of the shaft (the leg) is properly maintained, the forces acting in the sagittal direction should not be merely passive but should be the result of active muscle participation and tonic muscular tension. If muscular function is inhibited in the ankle area, greater loads will be placed on the knee”. – Kinematics of the Foot in the Ski Boot – Professor  Dr. M. Pfeiffer – Institute for the Athletic Science, University of Salzburg, Salzburg, Austria

It has been over 40 years since international authorities on sports science and safety raised red flags concerning the adverse effects of ski boots design and construction on skier stance, balance and the potential to cause or contribute to injury. It is time that their concerns were taken seriously and acted on. Research on stance and the effect of such things as zeppa and delta ramp angles is urgently needed.

 

STANCE MUSCLE TENSIONING SEQUENCE EXERCISE

Tensegrity

Tens(ion) + (Int)egrity 

The optimal ramp angle, as determined by the dynamic ramp device, is based on a stance predicated on the principles of tensegrity.

Fascial continuity suggests that the myofascia acts like an adjustable tensegrity around the skeleton – a continuous inward pulling tensional network like the elastics, with the bones acting like the struts in the tensegrity model, pushing out against the restricting ‘rubber bands: Tom Myers, Anatomy Trains (1.)

A ski stance based on the principles of tensegrity must be learned and rehearsed in a step-by-step process. It is neither natural or intuitive although elite skiers and racers such as Shiffrin and Hirscher appear to have acquired the elements of tensegrity. Assuming a group of racers of equal athletic ability, the odds will favour those whose stance is based on tensegrity.

In a ski stance base on tensegrity, tension in the arches of the feet will extend to the palms of the hands holding the poles.

  1. Start by standing barefoot on a hard flat floor or surface in a controlled environment such as your home. Where possible, use the same surface and place to rehearse the stance. If you have constructed a dynamic ramp assessment device, use this with the top plate set to level.
  2. Stand upright at attention. You should feel most of the weight under your  heels and less weight across the balls of your feet. This is normal. The fore-aft weight distribution is actually 50-50 heel to forefoot. But because the weight of the body is spread across the balls of the feet and along the outer aspect behind the small toes, more weight is sensed under the heels. Stand so your weight is distributed equally between both feet.
  3. Relax your hamstrings (in your thighs) and let your torso drop towards the floor.  Your knees move forward as they flex and your ankles will dorsiflex. Your ankles should stop dorsiflexing on their own when the front of your knee caps are aligned approximately over the balls of your feet. This is the point where the tension in your soleus (calf muscle) peaks with the tension in your arches. You should feel about the same pressure under the balls of your feet as you feel under your heels. But it should feel as if the circle of pressure under your heels has gotten bigger and your feet should feel more connected or integrated with the floor. I call this ‘rooted’ because it should feel as if your feet have sunk into the floor.
  4. While keeping your upper body erect, move slightly forward in the hips. You will quickly reach a point where you start to become unstable and feel as if you would fall forward onto your face if you move farther forward in the hips. When you get to this point your big toes should press down on the floor on their own to try stabilize you. This is the forward limit of stability.
  5. Now move rearward in the hips until you start to feel the same instability. This is the rearmost limit of stability.
  6. Now bend forward from the waist. Do not curl your back. Bend from the hip sockets for the thigh. The movement is actually thigh flexion. Lift your thigh to get the right feeling. As you bend forward from the waist, let your buttocks move rearward.  Your ankles and knees straighten. Allow your buttocks to drop towards the floor until you feel your body settling onto your feet. As this happens, reach forward with your arms as if you were going to hug a large barrel in front of you. Make sure the palms of your hands are facing each other with fingers curled and pointing towards each other. Find the place where your arms and head feel neutral to your spine. As your arms come into position you should feel your abdominal core and muscles in your back acquire tension.
  7. Experiment by increasing the amount of flexion at the waist while keeping solid pressure under your heels and balls of your feet as you straighten your knees slightly. As you increase the forward bend at the waist, pressure should increase under the balls of your feet. But you should not feel unstable. If anything, you should feel stronger and more stable. Make sure to keep solid pressure under your heels as you increase the pressure under the balls of your feet. You should feel as if the weight of your head and shoulders is pressing your feet down into the floor.
  8. Increase the bend at your waist while keeping the pressure on the balls of your feet and heels until the top of your head is down by your knees. You should still feel very strong and stable in the feet. The is the lowermost limit of waist flexion.

Once you have acquired a kinesthetic sense of the integrity of foot to hand tension, a sense of stability while pulsing the torso vertically up and down over the feet confirms a state of tensegrity.

The photo below is of simple model I designed and constructed in 1993 to illustrate the basic concept of bottom up tensegrity and how the degree of tension in the arches of the feet and the vertical biokinetic chain is driven by the weight of COM stacked over the foot.

The graphic below shows the continuum of tension from the balls of the feet to the opposite shoulders through the mechanism of the transverse posterior sling.

In my next post I will discuss what I term the NABOSO Effect.


  1. https://www.anatomytrains.com/fascia/tensegrity/