Zeppa-Delta Angle posts

DETERMINING OPTIMAL BOOT SHAFT/BOOT BOARD RAMP ANGLE

A follower of skimoves posed the following;

“I’m trying to determine my optimal boot shaft angle and ramp angle given my physiology – i.e. what works best for me. I’ve done some of this work on my own by adjusting binding ramp angle (last season). What is interesting is the shaft angle of my newer Head vs. Lange boots”.


As discussed in recent posts, the importance of the cumulative effect of boot board ramp (zeppa) and binding ramp (delta) angles on stance is becoming increasingly recognized. Although binding ramp angle (delta) typically varies widely from one binding to another in recreational bindings, boot board ramp angle seems to be coming into line with functional reality in race boots. Reliable sources in Europe tell me that the boot boot board ramp angle in World Cup boots is in the order of 2.6 degrees. After I eliminated the arch profile in boot boards for a 23.5 Head race boot, I calculated the ramp angle at 2.35 degrees, a far cry from the 5 degrees claimed for the boot boards. I calculated the boot board ramp angle of an Atomic race boot of a local ski pro at a little over 2 degrees. I have also been told that shim kits are available for all race bindings that allow the delta angle to be zeroed.

The default barefoot ramp angle for humans is zero. It has been unequivocally established that anything more than a small amount of ‘drop’ (heel higher than forefoot) in footwear will have a detrimental effect on stance, balance and movement patterns. This especially true for balance on one foot, something that is fundamental to sound ski technique.

Elevating the heel relative to the forefoot will cause the muscles in the back of the lower leg to contract. Over time, these muscles will become chronically shortened. The key muscles affected are the calf muscles; the gastrocnemius and soleus. But the small muscles that stabilize the knee and pelvis are also adversely affected, not a good thing.

If I want to find the optimal boot shaft angle and compare the shaft angle of two or more boots, I start by making the boot boards perfectly flat with the transverse aspect horizontal with the base of the ski. I set the boot board ramp angles for both boots at 2.5 or 2.6 degrees. Since it can take a long time for the body to adapt to even small changes in ramp angle underfoot, the angle is not hypercritical.   I have settled on 2.5 to 2.6 degrees of total ramp (zeppa + delta) as an arbitrary starting point. Although there appears to be a positive effect of a small delta binding angle in SL and GS, I prefer to work with a zero delta angle initially since a positive or negative delta affects the shaft angle of a ski boot.

When moving from one boot model to a different model or to another boot brand, the first thing I do is remove the boot boards and calculate the ramp angles with the top surface monplanar. If the boot boards are not flat, I plane or grind them flat. If a new boot is to be be compared to a current boot with a boot board angle of 2.5 to 2.6 degrees, I modify the boot board of the new boot so it has the same angle as the current boot.

Next, I compare the shells and the angles of the spine at the back of the shaft of each boot. Even if the angles of the spines of the boot shells appear similar, there is no guarantee that what I call the static preload shank angle (more on this in a future post) will be the same.

A quick check of how the structure of the shell of the new boot is affecting the functional configuration of the foot and leg compared to the current boot, is to put the current boot on one foot then put the new boot shell with the liner from the current boot on the other foot. If a significant difference is perceived, the source is the new shell.

At this point, it may be apparent that there is a difference in the shank angles of the left and right legs when comparing the current boot to the new boot. But whether one boot is better than the other or even if one boot eanables the optimal static preload shank angle would not be known. I will explain how I identify this angle in my next post. For now, study this recent video of Lindsey Vonn starting off by skiing in what appears to be a strange ski stance. In fact, the exercise Vonn is doing is a familiar routine to me, one that I do before I start skiing – https://www.facebook.com/LindseyVonnUSA/videos/10154672700589728/

Why is Vonn skiing this way? What is she trying to do?

Also, check out this screen shot of Anna Fenninger. Note her compact, forward in the hips stance.

fenninger-1

Finally, watch this video in which Brandon Dyksterhouse compares Shiffrin and Fenninger – Shiffrin GS Analysis – https://youtu.be/phchHWwDhdY

What do Vonn and Fenninger have in common? Why?

 

A READER RESPONDS TO BOOT BOARD RAMP ANGLE VS. BOOT SIZE

The reason I started this blog was to stimulate an intelligent dialogue on the issues pertaining to the design and modification of ski equipment and the formulation of ski technique based on sound principles of science. The comment below on BOOT BOARD (ZEPPA) RAMP ANGLE VS. BOOT SIZE was received today from Michael Pupko. I have underlined key statements.


Excellent presentation on boot length and the binding’s effect on net ramp. Anyone that is going to experiment with lowering their ramp angle needs to be aware that they will have to do something about the restriction on ‘ankle glide path,’ and the ability to flex their ankles within the ski boot shaft or they may end up with a false conclusion.

I didn’t have the smarts to start with the fact that the ski boot locks up the ankle and also ‘race fit’ etc. restricts all normal foot function. So my approach to not being able to flex my ankles enough to get out of the back seat was to raise the ramp angle because it does 2 things; first it ‘artificially’ gives the skier more forward lean without using up the limited ankle flex available thus getting them out of the back seat and second, from that position I found I could ‘drop’ into the tongue of the boot using body weight rather than the tiny muscles in the front of the shin that aren’t designed for bending rigid plastic ski boots. As I removed the obstacles to foot function, first by trial and a lot of error on my own and then with the help of this blog in regard to ankle glide path, allowing toe spread, and removing arch impediments I have greatly reduced my ramp down to a third of what it was at its’ literal zenith. The trouble with starting within a boot with too much ramp in the zeppa, one has to really tighten the boot cuff to prevent falling forward out of the boot. This is what David addresses before the skier steps into the bindings and those experimenting with ramp angle must do so also. I originally improved my fore/aft ‘balance’ by increasing the ramp angle but it kept my feet locked up or even increased that issue. Everything has to be fixed where the problem is to get the optimum results; adding oil to the car’s engine won’t help if the gas tank is empty.

I’ve been playing with body position while running this summer. Due to my knee issue, the only way I can run without stressing the knee is to land on the ball of my foot; forefoot strike. Going down hills this has been fine but I started playing with the position of my COM due to a discussion with a friend. I discovered that I was running downhill very much like walking down steps until I lowered my COM and that really smoothed out the foot strikes. What I realized is that in a sense I’m stepping down as if my foot is ramped but adjust it according to the slope and needs. Thus I can see why there needs to be some ramp in the ski equipment for going downhill but the industry has gone way overboard with net ramp and forward lean because someone decided to not bother with allowing natural ankle movement in ski boots. I tried to find my last pair of leather boots to see what was underfoot in them, but unfortunately had no luck. I have noticed for years from seeing old pictures of skiers in leather boots, how they flex normally like other sports. That still didn’t make me figure out that we should do likewise in ‘modern’ plastic ski boots because I believed they were made and fitted by experts that knew what they were doing. Thanks David for helping me get over that misconception!!

  • Michael Pupko

In my next post will explain why it is important for ankle flexion to occur within the confines of the boot shaft and how to determine optimal boot shaft angle.

BOOT BOARD (ZEPPA) RAMP ANGLE VS. BOOT SIZE

It is becoming clear, the angle the boot board (zeppa) establishes for the skier’s foot relative to the ground, is vitally important to the ability to balance and function on skis. Therefore, knowing boot board angle (ramp angle) and skier preferences should become part of every boot setup and purchase. Yet there appears to be a fundamental error in the understanding of ramp angle in boots. This is evident when someone states, for example: “The head Raptor has a ramp angle of 4.5 degrees”. The statement may only true if the angle is linked to the boot size.

There are production controls applied to boots just as controls and standards are applied to all other things mass produced. In boots, it means the first prototypes are designed to a specific size (generally Mondo 26). All other sizes are scaled up or down from it. Each Mondo size is a change of one centimeter. Zeppas are fixed in both rear foot and forefoot height in the prototype standard. Only the zeppa length changes as boot size changes.

It means; if the prototype size is twenty six, the zeppa of a twenty three is three centimeters shorter with the same toe and heel heights. Therefore, the ramp angle of the zeppa of a twenty three is steeper than the ramp angle of the zeppa of a twenty six. Since many women’s boots are scaled from the twenty-six Mondo standard, boot set-up problems can be more difficult to solve for women than for men. This is the reason women are more adversely affected by boot configuration than men. The graphic below compares the boot board (zeppa) ramp angles of larger and smaller boots to the standard Mondo 26 boot.

Zeppas Mondo 26

 

Bindings obviously confer the same effect, since with most models heel height is greater than toe height. As the heel and toe change distances from each other according to boot size, binding angle (delta) changes and its angle is additive with the boot ramp angle to determine gross equipment angle as shown in the graphic below. Binding delta has a double effect, since as delta increases boot cuff angle relative the ground also increases.

Zeppas Mondo 26 bindings

When talking about boot boad ramp, we should include the boot size or always use the ramp of the Mondo 26 as a known reference.


Lou Rosenfeld has an MSc. in Mechanical Engineering with Specialization in Biomechanics earned at the University of Calgary Human Performance Laboratory. His research was titled, “Are Foot Orthotic Caused Gait Changes Permanent”.

While at HPL, he assisted with research on the effects of binding position for Atomic, and later conducted research for Nordica that compared Campbell Balancer established binding position to the Nordica factory recommended binding position.

Lou is one of the invited boot-fitters on the EpicSki forum “Ask the Boot Guys” and has authored articles on boot fit, balance, alignment and binding position for Ski Canada, Ski Press, Super G, Calgary Herald, and Ski Racing, USA. He is a CSIA Level 2 instructor and CSCF Level 1 coach. He currently resides in Calgary where he owns and operates Lou’s Performance Centre. A selection of his articles may be found at www.Lous.ca.

BOOT BOARD STANDARD: A PROPOSED STARTING POINT

At the time that I designed the Birdcage research vehicle in 1991 with a biomedical engineer, I was aware that a Net Ramp Angle (boot board + binding ramp) of more 3 degrees had a significant, perceivable, negative effect on skier stance and balance. Although I didn’t know what the range of the optimal Net Ramp Angle was (and still don’t), I knew that Net Ramp Angle is affected by the length of the Achilles tendon and that this aspect affects the synchronizing of peak arch tension with peak Achilles tendon tension that occurs just before the heel separates from the ground to initiate propulsion. I refer to this as the Reference Shank Angle. It is the foundation on which to build a strong stance from the bottom up.

Since my experience prior to 1991 had demonstrated that more than 3 degrees of Net Ramp Angle was too much, a decision was made to fix the Net Ramp Angle of the base of the small Birdcage, shown below, at 2.5 degrees and the base of the large Birdcage at 2.35 degrees.

Screen Shot 2016-08-09 at 3.30.12 PM

The small Birdcage fit US men’s size 4 to 8 feet. The large Birdcage fit US men’s size 8 to 12 feet. Thus, all skiers with feet in a Birdcage size range had the same Net Ramp Angle.

Since the base of the Birdcage acted as the boot board, there was no removable boot board as in most ski boots. The base shown above was made from high grade aluminum and was in the order of many times stiffer and more torsionally rigid than was necessary to withstand the expected loads of skiing without deforming. This is an important factor that will be discussed in a future post.

Since 1978, I had suspected that the plastic shells of most, if not all, conventional ski boots were undergoing significant deformation under loads typically of racing. So I began stiffening the bottoms of ski boot shells with a torsion box structure similar to those used to stiffen skis. Recent studies have not only confirmed my suspicions, but shown that the deformation that occurs can be far worse than I suspected. Consistent with good practices of science-based research the entire Birdcage was engineered with excess structural capacity so as to ensure that it could easily withstand the maximum loads imposed on it without significant deformation as this could disrupt the processes of skier balance and control.

An important aspect of the Birdcage was continuity of the surface structure that the foot rests on. A one piece top sheet comprised of 5 mm thick high grade aluminum formed into a tub was secured to the base with screw fixations. The 3 black strain gauges shown mounted on the base (2) and side plate (1) in the photo below of a left foot Birdcage show the continuity of the surface under the balls of the feet. Continuity of the surface under the ball of the large toe is especially critical.

IMG_6453

In order to ensure each test skier was as close as possible to the Reference Shank Angle, the start and end points of shaft rotation and the forward end point at which resistance was introduced were adjusted to peak Achilles tension – Shank Reference Angle so as to make the effect of ramp angle as consistent and neutral as possible without fine tuning it to each test skier.

The photo below shows the rotation resistance control mechanism on the back of the Birdcage.

IMG_6451

This important aspect is discussed in detail in US Patent No. 5,265,350. FIG 56 below from the patent, shows the means to adjust the rearward travel limiter of the shaft to set the shaft forward lean angle, forward travel limiter of the shaft to set the limits of forward shank movement and journal resistance means for 10 to 12 degrees of low resistance shaft rotation.

Fig 56

A reasonable starting point for a boot board standard would include the following:

  • A ramp angle of 2.5 degrees with a  shim kit with 0.1 degree shims for the heel and forefoot to facilitate fine tuning based on ski testing.
  • A top plate surface that the foot rests on that is monoplanar (flat in the long and transverse planes) with the transverse plane parallel to the transverse aspect of the base of the ski.
  • Torsional qualities that when integrated with base of the boot shell maintain deformation of the boot board and boot shell base within agreed upon acceptable limits.
  • A top plate surface that the foot rests on that is contiguous under the heel and the balls of the feet, especially under the ball of the big toe under the the 5th metatarsal.

THE BOOT BOARD FACTOR

While the Ottawa researchers did not explore this aspect, they correctly identified that equipment, including custom insoles, technical skills and ski technique might explain why the pressures recorded under the heel and the head of the first metatarsal of some instructors were much higher than the pressures seen in the same locations in other instructors.  The University of Ottawa studies are the only ones I am aware where the researchers considered the effect  of what is known in research as uncontrolled variables on their findings. Poor technique and interference with the function of the foot and leg caused by the ski boot can ensure that COP remains under the heel.

Although boot board ramp angle and shape have an undeniable impact on the function of the feet and lower limbs, as evidenced by the photographs below of a sampling of boot boards, there does not appear to be any continuity, let alone any standard for boot board ramp angle and the form of the surface that interfaces with the sole of the foot.

1

 

2

IMG_5560

3

IMG_6187

4

IMG_0144

When the effect of  binding ramp angle, which appears to have even more variation than boot board ramp angle, is added to ramp angle equation to arrive at Net Ramp Angle, the possible combinations that make up Net Ramp Angles becomes unlimited and can range from as little as two to as much as ten degrees.

As if the lack of any apparent standard for boot board and binding ramp angles were not causing enough of an impact on skier/racer performance, there is a factor that appears to be compounding the issue by introducing a layer of inconsistency; boot base shell deformation under loads typical of recreational skiing.

I will discuss boot base shell  deformation in a future post. In my next post I will propose a starting point for a boot board standard.

STANCE KILLER: EXCESSIVE RAMP ANGLE

Ramp sole angle or drop, as it is called when the heel is elevated above the forefoot in footwear, affects the function of not just the foot, but the entire muscle-skeletal and balance systems.

With few, exceptions, the sole structure of most shoes elevates the heel above the forefoot. Prolonged activity in footwear with anything other than minimal drop will result in chronic contraction and shortening of the muscles in the backs of the lower leg.

“This is an extremely serious situation considering the fact that the shortened lower leg muscles are now contributing to faulty foot function in a number of ways. The most significant foot fault caused by elevated heels is that shortened posterior leg muscles pull improperly on the back of the heel (Achilles tendon) to unnaturally increase the amount of flattening the arch will undergo. Said another way, chronically shortened lower leg muscles increase pronation of the foot and ankle.

“A more significant and potentially debilitating effect of heel elevation is that there is an involuntary stretch reflex built into the posterior lower leg, that can only be activated if the heel is allowed to come close to the ground. This does not occur in most shoes available to consumers today, EVEN amongst athletic models”. – Northwest Foot & Ankle (nwfootankle.com)

__________________________________________

“Barefoot, the perpendicular line of the straight body column creates a ninety degree angle with the floor. On a two-inch heel, were the body a rigid column and forced to tilt forward, the angle would be reduced to seventy degrees, and to fifty-five degrees on a three-inch heel. Thus, for the body to maintain an erect position, a whole series of joint adjustments (ankle, knee, hip, spine, head) are required to regain and retain the erect stance.

“In this reflex adjustment scores of body parts — bones, ligaments and joints, muscles and tendons — head to foot must instantly change position.

“But shoe heels have other, lesser-known influences on gait. For example, any heel, low to high, requires a compensatory alteration or forward slant on the last, which is translated to the shoe. This slant is known as the “heel wedge angle.” This is the slope or slant of the heel seat, rear to front, to compensate for the shoe heel height. The higher the heel, the greater the angle.

“On the bare foot there is no wedge angle. The bottom of the heel is on a level one hundred and eighty degrees, with body weight shared equally between heel and ball. Inside the heeled shoe, the wedge angle shifts body weight forward so that on a low heel body weight is shared forty percent heel, sixty percent ball; and on a high heel ninety percent ball and ten percent heel.

“Let’s add one further influence of shoe heels, low to high. The shoe’s elevated heel shortens the Achilles tendon and accompanying shortening of the calf muscles.”  – Dr William A. Rossi, DPM. ‘Why Shoes Make ‘Normal’ Gait Impossible’ – Podiatry Management. March 1999.

Katy Bownman also talks extensively about the adverse effects of heel lift in her book Whole Body Barefoot: Transitioning Well to Minimal Footwear.

__________________________________________

The reason I started this blog on May 11, 2013 with my first post, A Cinderella Story: The ‘Myth’ of the Perfect Fit – https://skimoves.me/2013/05/11/the-myth-of-the-…sive-perfect-fit/, was because a number of issues in my mind were still nebulous. Even though my boot modification efforts over several decades had consistently met with success at the highest levels of Olympic and World Cup competition, I still had more questions than answers. I knew that I was close. But I did not yet have the big picture figured out. One question that remained unanswered was, is it possible to develop a formula for setting up the boot/binding/ski system that will consistently maximise skier/racer performance? One thing I was certain was critical to any formula is the angle of the ramp the skier stands on in relation to the surface of the snow under the base of the ski.

Since 1978, I had known that a combined ski boot boot board/binding ramp angle (Net Ramp Angle) of about 3 degrees was critical to the development of a strong stance and that the positive effects of ramp angle fell off dramatically at NRAs of more than 3 degrees. I had a hunch that less NRA than 3 degrees allowed a stronger stance. But I didn’t know the NRA optimal range and especially where the bottom end was at which NRA became too low.

When I designed the Birdcage in 1991 with a biomedical engineer, we made two sizes. The small size fit US men’s 4 to 8 feet. The base ramp angle was 2.5 degrees. The large size fit US men’s size 8 to 12 feet. The base ramp angle  2.35 degrees. The ramp angles were based on our theory that it was better to be on the low side of optimal than on the high side. We were hedging our bets by playing what we thought were the low and high ends of the optimal range with 2.35 and 2.50 degree ramp angles. The robust adjustment range of the Birdcage made it possible for skiers with up to size 8 US men’s feet to ski in both the small and large versions. This made it possible for some testers to compare the 2 different ramp angles.

For those of you who are not familiar with the Birdcage experiments, the links below are to 4 posts on the Birdcage in the order of first to last.

EPICSKI ARTICLE – THE BIRDCAGE EXPERIMENTS

https://skimoves.me/2014/03/03/epicski-article-…cage-experiments/

THE BIRDCAGE DATA – WORLD PREMIER

https://skimoves.me/2014/03/03/the-birdcage-data-world-premier/

THE BIRDCAGE EXPERIMENTS – DATA 3

https://skimoves.me/2014/03/05/the-birdcage-experiments-data-3/

BIRDCAGE VS. CONVENTIONAL

https://skimoves.me/2014/03/07/birdcage-vs-conventional/

__________________________________________

The Effect of Heel Lift or Ramp

Elevating the heel above the forefoot more than a small amount, tips the whole body forward. This provokes a compensatory balance response that alters the default angles of the ankle, knee and hip joints and the lengths of the associated muscles. This can dramatically affect the functional integrity of the foot and compromise the effectiveness of the balance system. That elevating the heel affects everyone in this manner is a virtual certainty.

Past a certain point, NRA in the stack of ski equipment between the sole of the foot and the surface of the snow will force a skier to retreat to weight borne on the heel with support for the leg from the rear of the boot shaft for stability.

After a lot of experimentation last season and input from reliable sources  in Europe I reached a tentative conclusion that the optimal Net Ramp Angle is in a range between 2.5 to 2.7 degrees. But nothing is really ever settled. A complicating factor is wearing shoes with varying degrees of drop. This prevents the balance system from using the default barefoot, zero drop balance reference or developing a consistent balance reference based on a fixed drop. Further exacberbating the effect of Net Ramp Angle is that boot boards are seldom monoplanar (dead flat in the x – y planes.

In my next post I will discuss the factors that add to and complicate the effects of Net Ramp Angle and my vision for a standard boot board ramp that would serve a ski stance/balance reference and a starting point for Net Ramp Angle Optimization.

 

MORGAN FROM FRANCE FINDS HIS RAMP ANGLE

When Morgan Petitniot from France first contacted me on September 2, 2014 (CASE STUDY: MORGAN FROM FRANCE – HIS STORY (https://skimoves.me/2015/11/30/case-study-morga…france-his-story/), I had not started to look critically at boot board ramp angle and Net Ramp Angle.

When I posted SKI BOOTS – WHAT’S YOUR ANGLE? and CALCULATING RAMP ANGLE, two years ago, I knew that ramp angle could affect the function and especially the balance of a skier. But I had no idea how critical ramp angle is. Through subjective experiments back in the late’ 70s, I had identified that a ramp angle in the range of about 3 degrees made it easier to ski. But I had not made any attempt to narrow down the range or pursue the issue further. Nor did I understand back then exactly how and why ramp angle affected a skier.

After Morgan sent me the video he made in which he documented his experiments with different boots and skis, (MORGANS’ EXPERIMENTS WITH BOOT SETUP: 2013 TO APRIL 2015 https://skimoves.me/2015/12/09/morgans-experime…13-to-april-2015/), the range of effects on his skiing that he experienced from different boots and skis far exceeded what I had expected. The problem was that there was no reference against which to compare the different components against and little or no structure to Morgan’s process that would have allowed him to control variables and isolate and identify the effect of each change.

Morgan started to make progress with his skiing after he discovered The Skier’s Manifesto and began applying my principles. While he got closer to skiing at the level that he wanted to reach, it became clear to me that something was still holding him back. It was about this time that the interactions I was having with those such as Michael was helping me to gain a better appreciation and understanding of the critical nature of boot board ramp and Net Ramp Angle.

After reviewing the video clip below of Morgan skiing on January 17 of 2016 I asked him to check the ramp angles of his boots and skis. The dated comments that follow are from our email exchanges subsequent to January 17.

Morgan has improved a lot since we started working together. To the untrained eye, he looks like he is skiing quite well. But there are subtle indications that he is not able to Get Over It (get CoM over the ball of his outside foot). Morgan senses and confirms what I am seeing.


Jan 18

Morgan: Ok David, on my Fisher ski boot I am at 3.6 degree net ramp angle. I had to screw à 5 mm plastic matérial under the toe pièce of my ski boot you see it on the attaches photo\

Feb 11

Me: The biggest change for most skiers is to maintain a compact stance throughout the turn. The knee is the joint whose angle changes the most. The ankle stays fixed in the resistive angle while the knee flexes on the inside leg and extends on the outside leg to move COM over the ball of the foot. Rotating the outside leg into the body and using the inside leg to steady the pelvis enables COM to be aligned and maintained over the ball of the outside foot.

I generally do not encourage laces on liners because they can obstruct the glide path of the ankle and pollute the mechanoreceptors in the ankle that are key to balance. The liner you are using appears to be very soft. So it is unlikely it is causing significant issues. In my experience, liners can cause more problems than boot shells.

March 6

Me: In the past few months I have learned a great deal about the importance of ramp angle. It seems as by chance I chose race bindings that have zero ramp angle  for my skis when I got them 2 years ago. I have since learned that very few bindings have zero ramp. I have checked many bindings last week and found that no consistency in ramp angle. They all seem to be different. Worse, it changes with boot length. This is a big problem. A few weeks ago, I reduced the ramp angle of the boot boards in my boots to 2.6 degrees from 3.0 degrees and immediately sensed a huge improvement in balance, ski control and the ability to absorb shocks.

A week ago I was asked by a relatively new skier to help her with her boots because she is taking her CSIA Level II course and experiencing difficulty trying to do the exercises. I checked her boots first. They were far too small, too tight and far too narrow in the forefoot. She has a small but wide forefoot. When I checked her bindings they had 1.9 degrees of ramp. Her total or net ramp is almost 6 degrees!

I am about to post on tests that can and should be done with the Stance Ramp. The first test is to double the 2.5 degrees of the ramp to 5.0 degrees. You will immediately feel unstable on the ramp. This is the minimal ramp that most recreational skiers have between their boots and bindings. Many skiers have far more.  The problem is that most recreational bindings available today cannot be shimmed. Please check your bindings. If they have anymore than 0.2 degrees or ramp it is difficult to adjust for this in the boot board. If your bindings have ramp, I suggest you try and borrow or rent a ski similar to yours with zero ramp bindings and do a comparison test. Also, please check your boot boards and, if necessary, adjust the ramp to about 2.6 degrees. You can do tests  by placing thin shims of polyethylene under the heel or fore foot between runs to fine tune the ramp.

Please let me know what you find.

The best way is to drop the heel by grinding or planing the boot board down. I use a very sharp block plane to do this.

Try and build a Stance Ramp as soon as possible. I will give you exercises that are very telling in terms of what works best. You can easily sense this. Make sure the material you use is very stiff. Reinforce it, if necessary. You can easily bend the Stance Ramp platform it with pressure on the balls of the feet unless it is very stiff.

Morgan: I answer you quickly. According to your advices about ramp angle on december 2015, I have bought my skis “ATOMIC REDSTER SL” because of the binding ramp angle = 0°

Actually my boot board ramp angle (in the Fischers) is 3.8 !!!

I will made the test with trying to lift the forefoot (i don’t know if i have sufficient space to lift up my foot about 5 mm)

I am testing 2 pair of boot (head raptor 130 RS with 2.5 boot board ramp angle AND Fischer RC4 withe 3.6 boot board ramp angle) Now the only thing I can tell you : After 2 weeks I feel better in Fischer (edging, shank angle, more balance) but my back suffer. In Head boot (edging more difficult, shank angle not sufficient, balance –) but my back is better. Perhaps there is something to explore unless you have already understand what is happen 😉

March 7

Skype meeting to discuss next steps

March 17 – A Happy Ending

Morgan: I have the pleasure to say to you that. My back don’t hurt me anymore 🙂 🙂 Total ramp angle 2.8 (ski binding 0, boot board ramp angle 2.8)

More power, more balance, more reaction of skis. Gliding with the skis straight away, more relax and stable position and the feeling of the center position.

Great !!!