EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Ski Gear Discussion › Fit versus Function, or Why Do Boots Still Hurt?
New Posts  All Forums:Forum Nav:

Fit versus Function, or Why Do Boots Still Hurt? - Page 2

post #31 of 58
Thread Starter 
Quote:
Originally Posted by bjohansson View Post

I know the OP has spent eons and $millions$ on bootfitting and can't seem to find the cosmic connection, but that doesn't mean nobody can.

No, only a few centuries and a few 100K. biggrin.gif But what's funnier is that the large majority of readers seem to feel this is a sour grapes thread. When it's not about my feet or my adventures with boots. That's the lead-in story. My point is questioning how and why we have come to accept current boots as a good marriage of fit and function. I think we've bought into a marketing narrative about how boots are supposed to fit, and do their work. Most think otherwise...th_dunno-1[1].gif


Quote:

Originally Posted by mdf View Post

I find this "molds are hideously expensive" argument ridiculous.  

Consider for example this company I found by a quick google search...

 

http://www.armstrongmold.com/pages/rapidinjection.html

"Rapid Injection Molding allows us to make prototype injection molded parts in a production thermoplastic resin in 2-5 weeks. These parts may be used for full functional and fit testing as well as test marketing.  Bridge or production tooling - molds can run 1000's of parts"

 

The real problem is that stocking and distributing a lot of sizes and widths is just too much trouble.


^^^^ This. IMO folks who think we are straining the technological envelope here just don't understand late capitalism. This isn't about new tech being too complicated or expensive, it's about people being happy to pay for what's out there already, and retailers being understandably wary of cool new designs that no one might try. Supply and demand in the age of advertising and conditioned consumers. 

 


Edited by beyond - 10/17/11 at 6:34am
post #32 of 58
Quote:
Originally Posted by beyond View Post

But what's funnier is that the large majority of readers seem to feel this is a sour grapes thread. When it's not about my feet or my adventures with boots. That's the lead-in story. My point is questioning how and why we have come to accept current boots as a good marriage of fit and function. 


I think many people do feel that their boots are a good marriage of fit and function, relatively speaking.  Any 'footwear' that disables natural foot movement is going to have an impact and plastic isn't the best warm retention material on the planet - hence, most of us are pretty happy to be in a warm street shoe at the end of the day.  FWIW, I have the opposite problem you have - my foot is a B+ width in a weighted stance and is an 'easy' shape.  I only fit in a snug, narrow, boot, and when was the last time you saw one of those targeted to an advancing intermediate?

 

I raised this question early on to your main point:  "how do you change the boot without changing the binding?".  Following your Unification Theory, does a snowboard need the same kind of release as a pair of skis in a typical crash?  Therefore, does it need the same kind of binding, and therefore boot?  Shaped 'board' design may translate, but does binding translate in terms of performance and injury mitigation?

 

Boots continue to me to be an output of a rigid binding mount with a mechanical release system.  It would seem that all of this design does not begin with fit vs. function - the first principle is an acceptable level of injury rate and mitigation.  Hence, at least for now, a rigid mechanical release binding forces a rigid lower boot shell design (at a common standard for binding interface) that forces a hinge for flex in the upper shell.  In this context, you could argue that boots are (properly) form following function until a better safety mechanism is designed.

 

For better or worse, we seem to be in a ski/binding/boot equilibrium, and equilibrium can be hard to change.  So we see changes in skis, very little in bindings, and changes in boots designed to mitigate the negative 'fit' effects of the boot/binding relationship.  

 

And so the Burton Theory of Skiing Unification is countered by Why You Aren't a Snowboarder.  Not strapping a long board with grippy edges to each foot by a rigid system when one is going snow surfing is probably 90% of how you address binding and boots.  But skiing is sexy, and high heels have yet to go out of style, too.

 

 

 

 

 

post #33 of 58
Quote:
Originally Posted by NayBreak View Post

I think many people do feel that their boots are a good marriage of fit and function, relatively speaking.  Any 'footwear' that disables natural foot movement is going to have an impact and plastic isn't the best warm retention material on the planet - hence, most of us are pretty happy to be in a warm street shoe at the end of the day.  FWIW, I have the opposite problem you have - my foot is a B+ width in a weighted stance and is an 'easy' shape.  I only fit in a snug, narrow, boot, and when was the last time you saw one of those targeted to an advancing intermediate?

 

I raised this question early on to your main point:  "how do you change the boot without changing the binding?".  Following your Unification Theory, does a snowboard need the same kind of release as a pair of skis in a typical crash?  Therefore, does it need the same kind of binding, and at the end of the design process, boot?  Shaped 'board' design may translate, but does binding translate in terms of performance and injury mitigation?  Snowboarding didn't start with the boot, it started with the board.

 

Boots continue to me to be an output of a rigid binding mount with a mechanical release system.  It would seem that all of this design does not begin with fit vs. function - the first principle is an acceptable level of injury rate and mitigation.  Hence, at least for now, a rigid mechanical release binding forces a rigid lower boot shell design (at a common standard for binding interface) that forces a hinge for flex in the upper shell.  In this context, you could argue that boots are (properly) form following function until a better safety mechanism is designed.

 

For better or worse, we seem to be in a ski/binding/boot equilibrium, and equilibrium can be hard to change.  So we see changes in skis, very little in bindings, and changes in boots designed to mitigate the negative 'fit' effects of the boot/binding relationship.  

 

And so the Burton Theory of Skiing Unification is countered by Why You Aren't a Snowboarder.  Not strapping a long board with grippy edges to each foot by a rigid system when one is going snow surfing is probably 90% of how you address binding and boots.  But skiing is sexy, and high heels have yet to go out of style, too.

 

 

 

 

 



 

post #34 of 58
Thread Starter 
Quote:
Originally Posted by NayBreak View Post

 

Boots continue to me to be an output of a rigid binding mount with a mechanical release system.  It would seem that all of this design does not begin with fit vs. function - the first principle is an acceptable level of injury rate and mitigation.  Hence, at least for now, a rigid mechanical release binding forces a rigid lower boot shell design (at a common standard for binding interface) that forces a hinge for flex in the upper shell.  In this context, you could argue that boots are (properly) form following function until a better safety mechanism is designed.

 


Interesting point. My Grand Unification Boot (hereafter GUB) will look like a snowboard boot with an exoskeleton. Not an insect-like exoskeleton (that's what a boot is now), but a more human approach (think rib cage and clavicle). So struts that follow angles of force, connect to each other at points where our own movements occur across joints. Rigid where it needed to be for transmission of force to the ski, just snowboard boot where it did not need to transmit force. The bottom of the boot could have an attachment link to a plate that sensed load, released in appropriate directions when needed. If you wanted to use existing binding designs, then shelf in front of toe and behind heel would be rigid, as now, attach directly to exoskeleton, binding wouldn't know it's not a traditional boot. And exotic materials are cheaper if you don't make an entire shell from them, just some struts and braces. 

 

Put another way, why do we need the entire boot to be rigid plastic? If you can cut windows in a boot shell around the 5th metatarsal, as they did with Solly's and Atomics, you can create a GUB that's mostly "liner," just uses hard materials where the force concentrates. To be determined: Whether you could have the exoskeleton as part of the binding, just slip your snowboot in, connect, and go. 

post #35 of 58
Quote:
Originally Posted by beyond View Post

To be determined: Whether you could have the exoskeleton as part of the binding, just slip your snowboot in, connect, and go. 


You would probably need an electronic binding release so the exo could fully release.  And that seems to be something of the crux - will people accept sensor based electronic bindings?

 

And also, why the hell can't I edit my posts without creating new ones redface.gif

 

post #36 of 58
Quote:
Originally Posted by beyond View Post

Interesting point. My Grand Unification Boot (hereafter GUB) will look like a snowboard boot with an exoskeleton. Not an insect-like exoskeleton (that's what a boot is now), but a more human approach (think rib cage and clavicle). So struts that follow angles of force, connect to each other at points where our own movements occur across joints. Rigid where it needed to be for transmission of force to the ski, just snowboard boot where it did not need to transmit force. The bottom of the boot could have an attachment link to a plate that sensed load, released in appropriate directions when needed. If you wanted to use existing binding designs, then shelf in front of toe and behind heel would be rigid, as now, attach directly to exoskeleton, binding wouldn't know it's not a traditional boot. And exotic materials are cheaper if you don't make an entire shell from them, just some struts and braces. 

 

Put another way, why do we need the entire boot to be rigid plastic? If you can cut windows in a boot shell around the 5th metatarsal, as they did with Solly's and Atomics, you can create a GUB that's mostly "liner," just uses hard materials where the force concentrates. To be determined: Whether you could have the exoskeleton as part of the binding, just slip your snowboot in, connect, and go. 

Didn't some boot manufacturer (Nordica?) try this?  As I recall it failed miserably.  Skiing used to be hard when we had flexible boots.  Plastic boots made skiing much, much, MUCH easier.  I don't know anybody that would advocate reverting to the techniques we had to use in the early 60s to make skis turn. 

 

 

post #37 of 58

It seems you're describing something like a custom made orthopedic brace.  I don't think you could manufacture such items in pairs for twice the cost of high end ski boots.  I know a single custom knee brace goes for more than $600.

post #38 of 58
Quote:
Originally Posted by beyond View Post

Interesting point. My Grand Unification Boot (hereafter GUB) will look like a snowboard boot with an exoskeleton. Not an insect-like exoskeleton (that's what a boot is now), but a more human approach (think rib cage and clavicle). So struts that follow angles of force, connect to each other at points where our own movements occur across joints. Rigid where it needed to be for transmission of force to the ski, just snowboard boot where it did not need to transmit force. The bottom of the boot could have an attachment link to a plate that sensed load, released in appropriate directions when needed. If you wanted to use existing binding designs, then shelf in front of toe and behind heel would be rigid, as now, attach directly to exoskeleton, binding wouldn't know it's not a traditional boot. And exotic materials are cheaper if you don't make an entire shell from them, just some struts and braces.



Apex is there already:

 

inspiration.jpgCHASSIS_001.jpg

post #39 of 58
Quote:
Originally Posted by beyond View Post
As we now know, recent empirical testing has shown that ... humans are by nature forefoot strikers and in that position seldom overpronate, regardless of their arch,.

 

Wrong.

 

Foot Strike Patterns of Runners At the 15-Km Point During An Elite-Level Half Marathon

 

"Four hundred fifteen runners were filmed by 2 120-Hz video cameras in the height of 0.15 m placed at the 15.0-km point and obtained sagittal foot landing and taking off images for 283 runners. Rearfoot strike was observed in 74.9% of all analyzed runners, Midfoot Strike in 23.7%, and Forefoot in 1.4%."

 

http://journals.lww.com/nsca-jscr/Abstract/2007/08000/Foot_Strike_Patterns_of_Runners_At_the_15_Km_Point.40.aspx

post #40 of 58
Quote:
Originally Posted by Stikki View Post

 

Wrong.

 

Foot Strike Patterns of Runners At the 15-Km Point During An Elite-Level Half Marathon

 

"Four hundred fifteen runners were filmed by 2 120-Hz video cameras in the height of 0.15 m placed at the 15.0-km point and obtained sagittal foot landing and taking off images for 283 runners. Rearfoot strike was observed in 74.9% of all analyzed runners, Midfoot Strike in 23.7%, and Forefoot in 1.4%."

 

http://journals.lww.com/nsca-jscr/Abstract/2007/08000/Foot_Strike_Patterns_of_Runners_At_the_15_Km_Point.40.aspx



I don't think that speaks to whether they're heel strikers by nature or by training and shoe constraints.

post #41 of 58
Quote:
Originally Posted by cantunamunch View Post

Apex is there already:

 

inspiration.jpgCHASSIS_001.jpg


There you go - and for a cool $1,295 you can be an early adopter.

 

post #42 of 58

How wide a forefoot are you trying to fit?  I think in most worlds, Old School SL is going to be screwed with a narrow heel and a 120mm forefoot, but I've seen fitters get impressively wide feet into plug boots, which seem to be the best remedy for narrow heels.

 

I think part of the reason you're seeing the size/shape limitations you are is that most of the boot companies are european, and from what I hear, there isn't a lot of attention paid to individual morphology over there, even as far as sole canting and such.  The guys who get to be really good either have great morphology or are great at adapting to what's currently on the market, so when they're asked for input in designing the next series of boots, they don't see much need for change.  I can see where they're coming from, because with a 97mm forefoot and a great bootfitter, I ski very comfortably in plug boots all day long.

 

I think if you're looking for a more tailored approach than a plug or something like the Daleboot, you're going to have to wait on a boutique shop to figure out how to make a range of uncommon sizes inexpensively enough that they can afford to sell them for a price you're willing to pay.

 

I don't get the 3-piece boot requirement, though.  One of the best things I ever did for my skiing was to get out of a pair of those and into a plug.  It's not as comfy for walking around, but it skis a heck of a lot better in all conditions.

post #43 of 58
Quote:
Originally Posted by cantunamunch View Post

I don't think that speaks to whether they're heel strikers by nature or by training and shoe constraints.

 

 

Foot Strike Contact Location and Foot Loading During the Development of Running in Children Age 3 to 11 Years

 

"Our hypothesis that during running the younger children in our study would land flatfooted or on their forefoot did not hold. The majority of children over the entire age range examined, ages 3 to 11, were heel strikers.

 

"At the younger ages, 80% or more of the children landed on their heel (Table 1). By the age of 6 most children were heel strikers (> 93.3%)"
 

http://www.asbweb.org/conferences/2009/743.pdf

 

 

Yes, I understand this study was part of the Nike Sport Research Lab but even those researchers thought children ran more flat footed than they actually do. And this study wasn't limited to the US, Japanese, Brazilian and German kids were part of the three year study.

post #44 of 58

Thanks for that.    icon14.gif    I wasn't going to  quibble about who did the study.

post #45 of 58

Pfft.  All we really need is for the ski binding and ski boot industry to get with the program now that the average ski is at least 10mm (more like 30?) wider than they were in the 60s yet the boot sole width and binding claws are still the same as they were back then.  Only pure race boots need to be 60 something mm wide and thin enough not to boot out with the current level of rise allowed.

 

Change the industry standard width of the binding claws and boot soles and the problem goes away.

 

Thanks, and keep the change..

 

P.S.  standard ski bindings mounted in a 120 mm wide ski look totally ridiculous!

post #46 of 58

Interesting thread.  Here are my thoughts, not backed up by any science, but seemingly intuitive to  me...

 

1. It's only the bottom of the foot that is suited to the magnitude and duration of forces that we're talking about here.  The rest of the foot/ankle/lower leg did not evolve to be so tough.

 

2. Because we're attaching a lever to our foot, we need to stabilize the foot and ankle.  In theory, it would be great to "go natural" and rely on our brute strength, but it seems to me that the anatomy isn't set up to provide enough strength to resist sudden forces acting on the ski tip.  So, unnaturally long lever leads to unnatural stabilizer.  Otherwise, we'd have a lot of torn calves/achilles, etc.  I don't think the stiffness of the boot is just for the binding interface.

 

3. Providing contact at obvious bearing surfaces isn't enough.  Consider the shin as a simple example.  Assume that we want to apply some pressure to the font of the ski.  We'll want to press the shin bone against the boot tongue.  This will not be very comfortable according to #1 above.  The flesh between the tibia and boot liner will get squeezed and begin to hurt.  What's the solution?  To spread the force over a greater area.  So, we'll engage the tissue/muscle on the outer side of the shin against the boot liner.  But, this area isn't bone; it's flesh.  In this situation, it acts like a liquid inside an elastic container.  If we press the front, it spreads toward the back.  So, if we want to relieve pressure on the tibia, we need not only to provide a bearing surface for the adjacent tibialis muscle, but we must also surround all the muscles with sufficient pressure.  Only by keeping all the muscles of the lower leg from moving around, can we use the muscle at the front to press the boot forward.  It's basically hydraulics.

 

4. Not only does the foot/leg behave a bit like a liquid, it requires liquid blood.  The boot/liner can't squeeze so hard for so long that the foot is starved of blood.  This is an area where people probably differ a lot based on activity levels, pain thresholds and physiology.  It's interesting to note, though, that other liquids in the foot, such as lymph, will slowly migrate out of the boot due to the pressure.  So, the fit changes.

 

Anyway, I think we're left with a tricky problem as we want to connect to the skis with a minimum amount of slop, and do it for many days in a row.

 

It would seem to me that a modest improvement could come from an increased diversity of molds, or perhaps even on-demand custom fabrication.  I'd suggest that making shells in half-sizes could help those on the cusp.  Perhaps four widths: narrow/wide X heel/toe, could get us closer out of the box.  It may very well be that we already have a rag-tag version of this courtesy of different manufacturers' styles, lasts, etc.  Only an expert can navigate these options, and probably there are gaps and redundancies.

 

It would be interesting to make expert bootfitting less necessary or less involved for more people.  There are clearly economic factors at work here, being that fitters are the manufacturers' customers, but I think good bootfitters would still have business.

 

Finally, it does seem odd when I have to explain to beginning/non-skiers that one should spend $500+ to get boots custom fitted by an expert, requiring a number of hours and iterations, even if their feet aren't unusually shaped.  It should be more like getting a pair of eyeglasses.

post #47 of 58

Boot manufacturers seem happy to sell the general public boots that feel OK in the store then turn to sloppy crap after three weeks of actual skiing.   After all, that is probably about how many days most boots get used.  Three years of one week wonder skiers and it's time to buy new boots again anyway-planned obsolescence right?.  Anyone that skis more than that also knows (or should know) that buying boots a little smaller than the chart says to and packing them out  and also possibly having them custom fitted is the only way to go if you want more than a few weeks of really good use from a pair of ski boots.

post #48 of 58

Oh Joy!!!! I thought it was my feet that needed fixing!!!

LS put away the skill saw ya dont have to trim my feet it says right here LOOK !

post #49 of 58
Thread Starter 
Quote:
Originally Posted by Stikki View Post

 

Wrong.

 

Foot Strike Patterns of Runners At the 15-Km Point During An Elite-Level Half Marathon

 

"Four hundred fifteen runners were filmed by 2 120-Hz video cameras in the height of 0.15 m placed at the 15.0-km point and obtained sagittal foot landing and taking off images for 283 runners. Rearfoot strike was observed in 74.9% of all analyzed runners, Midfoot Strike in 23.7%, and Forefoot in 1.4%."

 

http://journals.lww.com/nsca-jscr/Abstract/2007/08000/Foot_Strike_Patterns_of_Runners_At_the_15_Km_Point.40.aspx

OK, this is called thread drift. Based on one line in one of my posts. But here goes:


There's nothing surprising in your first link, and it doesn't address what I'm talking about in this thread, which is movements of the foot while the tibia is flexing forward. But as far as running distance, anyone who's every competed knows that as you go longer, you move from a forefoot to a midfoot or rearfoot strike. It's largely due to the loads placed on the tibial muscles and ligaments of the foot over thousands of foot strikes. This is actually mentioned at the end of the abstract, which address the finding that the better runners had a higher percentage of midfoot strikers: "The findings of this study indicate that foot strike patterns are related to running speed. The percentage of RFS increases with the decreasing of the running speed; conversely, the percentage of MFS increases as the running speed increases. A shorter contact time and a higher frequency of inversion at the foot contact might contribute to higher running economy." Put another way, the faster you get done, the fewer foot strikes, and thus the greater likelihood you can stay up off your heels. It's the plodders who get bone spurs, plantar fasciitis, and blood in their urine, not the guys coming in at 2:30. 

 

More to the point, when I stated that a forefoot strike was "natural," I was alluding to Dan Lieberman's recent article in Nature Jan 28, 20120 showing that folks who had always run barefoot tended to run with a midfoot/forefoot strike, while folks who had always run in shoes tended to have a rearfoot strike. (For the uninitiated, Nature is one of the world's most prestigious scientific journals, very tough to get past the peer review.) In other papers, Dan has discussed the evolutionary significance of barefoot running. Significantly, there is no evidence that we evolved to run either on concrete or for 26 miles without stopping. Most HG's who use endurance running to chase down animals in fact do a sort of relay race. Check out many heel strikers there are at 1500 K, for a better picture of how we may have evolved to run. The running surfaces are irregular. And they run on their forefeet, with very brief contact times. This is in line with studies that show barefoot runners not only run on their forefeet/midfeet, but they run with a different stance - more upright, less flexion at the knees - because they are not having to absorb as much shock. The net shock at the plantar surface is closer to even then, but the knees - and in turns out, the spine - are taking up the slack.

 

So data from a marathon, being run by a vast majority of folks who have always run with shoes, doesn't really address what's natural, just what our feet and legs have adapted to. And clearly, we've learned to be heel strikers.

 

Quote:
Originally Posted by Stikki View Post

 

 

Foot Strike Contact Location and Foot Loading During the Development of Running in Children Age 3 to 11 Years

 

"Our hypothesis that during running the younger children in our study would land flatfooted or on their forefoot did not hold. The majority of children over the entire age range examined, ages 3 to 11, were heel strikers.

 

"At the younger ages, 80% or more of the children landed on their heel (Table 1). By the age of 6 most children were heel strikers (> 93.3%)" 

http://www.asbweb.org/conferences/2009/743.pdf

 

 

Yes, I understand this study was part of the Nike Sport Research Lab but even those researchers thought children ran more flat footed than they actually do. And this study wasn't limited to the US, Japanese, Brazilian and German kids were part of the three year study.

 


One of the issues with using press releases, rather than peer-reviewed articles, as the basis for arguments like this is that you don't get the benefit of close scrutiny from other specialists in the field. I am not one of the latter, but even I notice the following: 1) The method of assessing load, summed force, completely ignores a large literature that shows even heel strikers spend most of their time on their forefoot. (Check out De Cock et al., Gait and Posture, 27, 2008 for a great map of pressure points by time as the foot makes contact.) As a result, the forefoot gets a disproportionate total load if not corrected for load/unit time. The article doesn't do that. Load per unit time is higher at the heel, which leads to a higher risk of various injuries as dwell time increases. 2) The article ignores that children exposed to leather shoes show significant changes in their tibio-talar joint (including nearly doubling its ROM - range of motion) because the foot is prevented from expanding along the lateral diagonal of the metatarsal base. Increased ROM in the tibio-talar joint is associated with increased risk of later pathology. It's also associated with heel strikes. Children wearing flexible sneakers show somewhat less ROM, although still above barefoot baseline. So unless the study corrects for whether the kids have worn shoes, and for how long, and of what type, its "surprise" finding of all these heel strikers could be attributed to their history of footwear, rather than a natural propensity to heel strike. Moreover, the study does not appear to correct for foot speed, which is central to any discussion of heel vs. forefoot strikes. As you slow to a jog, and then to a fast walk, you move toward a typical heel strike characteristic of walking. (And no, there is not evidence that because we are heel strikers while walking, we should be heel strikers while running. Very different mechanics.) So perhaps the kids run with a heel strike because they run slowly. See the issues that need to be addressed before we can celebrate heel strikes as natural?

 

So I'll stick with my statement about forefoot/midfoot strike, and let's return to the thread, maybe? 

 

 

post #50 of 58
Thread Starter 
Quote:
Originally Posted by Xela View Post

Interesting thread.  Here are my thoughts, not backed up by any science, but seemingly intuitive to  me...

 

1. It's only the bottom of the foot that is suited to the magnitude and duration of forces that we're talking about here.  The rest of the foot/ankle/lower leg did not evolve to be so tough. Nor did the base of the foot, which is why we get plantar fasciitis and then bone spurs...

 

2. Because we're attaching a lever to our foot, we need to stabilize the foot and ankle.  In theory, it would be great to "go natural" and rely on our brute strength, but it seems to me that the anatomy isn't set up to provide enough strength to resist sudden forces acting on the ski tip.  So, unnaturally long lever leads to unnatural stabilizer.  Otherwise, we'd have a lot of torn calves/achilles, etc.  I don't think the stiffness of the boot is just for the binding interface. Nice point. Yeah, suspect the boot shaft can be thought of as a level to increase efficiency of muscular force, maybe other parts of boot. But my question is what is the price of stabilization so you can multiply force? Seems to me that over in the instruction forum, it's all about foot motions, and using the toes to initiate, and so on. Plus, as I showed earlier, the ankle is really a complicated saddle joint, not a simple hinge. So as we reduce movement to help direct force more efficiently, aren't we also making our small muscle involvement more difficult? Eg, our balance and initiation?

 

3. Providing contact at obvious bearing surfaces isn't enough.  Consider the shin as a simple example.  Assume that we want to apply some pressure to the font of the ski.  We'll want to press the shin bone against the boot tongue.  This will not be very comfortable according to #1 above.  The flesh between the tibia and boot liner will get squeezed and begin to hurt.  What's the solution?  To spread the force over a greater area.  So, we'll engage the tissue/muscle on the outer side of the shin against the boot liner.  But, this area isn't bone; it's flesh.  In this situation, it acts like a liquid inside an elastic container.  If we press the front, it spreads toward the back.  So, if we want to relieve pressure on the tibia, we need not only to provide a bearing surface for the adjacent tibialis muscle, but we must also surround all the muscles with sufficient pressure.  Only by keeping all the muscles of the lower leg from moving around, can we use the muscle at the front to press the boot forward.  It's basically hydraulics. No, it isn't. Muscle doesn't act like the goo in a kid's squeeze toy. It's bounded by connective tissue, and compartmentalized with fascia that controls and redirects its contractions. It's limited by the bones to which it's attached. Plus, why not direct the force over a greater area of the exoskeleton, instead of over more of our shin? Our bodies shouldn't be the shock absorbers for a rigid boot. 

 

4. Not only does the foot/leg behave a bit like a liquid, it requires liquid blood.  The boot/liner can't squeeze so hard for so long that the foot is starved of blood.  This is an area where people probably differ a lot based on activity levels, pain thresholds and physiology.  It's interesting to note, though, that other liquids in the foot, such as lymph, will slowly migrate out of the boot due to the pressure.  So, the fit changes. Agree. Fit changes over the course of a day for sure. However, this seems to be an argument for a softer boot and rigid exo. 

 

Anyway, I think we're left with a tricky problem as we want to connect to the skis with a minimum amount of slop, and do it for many days in a row.

 

It would seem to me that a modest improvement could come from an increased diversity of molds, or perhaps even on-demand custom fabrication.  I'd suggest that making shells in half-sizes could help those on the cusp.  Perhaps four widths: narrow/wide X heel/toe, could get us closer out of the box.  It may very well be that we already have a rag-tag version of this courtesy of different manufacturers' styles, lasts, etc.  Only an expert can navigate these options, and probably there are gaps and redundancies. All true, but IMO this is simply making the existing tech better, not developing something new. Do we just want the existing tech with a better fit? 

 

It would be interesting to make expert bootfitting less necessary or less involved for more people.  There are clearly economic factors at work here, being that fitters are the manufacturers' customers, but I think good bootfitters would still have business. I'm feeling that actually there are very few expert fitters out there for the total number of boots sold. Bet most folks get them at big box stores, never even get the boot dialed in. 

 

Finally, it does seem odd when I have to explain to beginning/non-skiers that one should spend $500+ to get boots custom fitted by an expert, requiring a number of hours and iterations, even if their feet aren't unusually shaped.  It should be more like getting a pair of eyeglasses. Amen.


Nice...

 

post #51 of 58

OK, a reply to beyond's reply:

 

#1.  Are you saying the base of the foot didn't evolve to support the forces of standing, walking and running?  Or, are you saying it didn't evolve sufficiently to avoid all problems?  Certainly, the fat pad under the heel is evidence of specialized adaptation underfoot.

 

#2. There does seem to be a natural tension between fine foot motions and stability.  The logical conclusion might be shorter skis, but we know they perform worse in a number of conditions.

 

#3. I'm going to defend my bag-of-goo analogy.  Muscles and connective tissue may be firm, but they're still gooey enough.  If I tense a muscle, I can still jab my finger into it a few millimeters.  Consider the tibialis, stretching from knee to ankle (approximately), and as tense as possible.  Now consider a rope stretched tightly between two trees.  As tight as that rope is, I can still push sideways on its midpoint and deflect it an inch or two.  The tibialis needs only to deflect a few millimeters before it's no longer relieving a much pressure on the tibia.

 

#4. A softer boot paired with an exoskeleton will be comfy for sure, but won't it damp energy transmission from our bodies to the skis?  Back to the shin:  If there's 1/2 inch of soft foam between the front of my shin and the boot's exoskeleton, and I want to push the top of the boot 1/2 inch, I need to move 1 whole inch, with pretty much nothing happening for the first half.  I think this is the engineering definition of "slop".

 

I think the answer may lie in the use of firm bearing surfaces at a number of key places, but soft or open materials elsewhere.  There are challenges to this, such as #3.  If we assume that we're not making the absolute highest-performing boot possible, we could deal with it.  Imagine a boot liner made out of a "checkerboard" of two materials: one firm, the other soft.  This would allow more blood flow while still managing slop.  We could do better by arranging the firm "squares" into strategic places, and using appropriate rounded shapes rather than squares.  Where the soft parts of the liner are, the corresponding parts of the boot shell could be cut away, assuming the shell is made of a strong enough material.  Note that some spots would have firm foam not for direct transmission of force, but to contain and direct the "bag of goo".

post #52 of 58


 


Originally Posted by Xela

 

 

 

Anyway, I think we're left with a tricky problem as we want to connect to the skis with a minimum amount of slop, and do it for many days in a row.

 

Nah.  IMHO most boots should be a laterally stiff as a race boot.  Make the forward pressure adjustable and most skiers can dial into a boot that works for most conditions.

 

It would seem to me that a modest improvement could come from an increased diversity of molds, or perhaps even on-demand custom fabrication.  I'd suggest that making shells in half-sizes could help those on the cusp.  Perhaps four widths: narrow/wide X heel/toe, could get us closer out of the box.  It may very well be that we already have a rag-tag version of this courtesy of different manufacturers' styles, lasts, etc.  Only an expert can navigate these options, and probably there are gaps and redundancies.

 

Daleboot can fit just about any foot/lower leg combination (even if they are different from foot to foot) and have done so before many skiers were born.  Too bad they have so few places to get a fitting.  Most people never heard of them because they are mostly selling direct.  The other option for most people is the Fischer Vacuum boot.  It should work for most hard to fit people and actually is molded to the foot, making it a more precise fit than Daleboot. 

 

It would be interesting to make expert bootfitting less necessary or less involved for more people.  There are clearly economic factors at work here, being that fitters are the manufacturers' customers, but I think good bootfitters would still have business.

 

A lot of skiers purchase equipment from "big box" stores.  I think this is clearly wrong, but that is another matter.  Experience tells me big box stores (with employee turnover) will always screw things up a lot more than a shop owned by skiing experts, so they seek out equipment that is as close to idiot proof as possible.  That is why the big box store flock to integrated bindings.  Apex ski boots should interest the big box stores, too.   So what?  When I see a doctor, I want someone who won't screw up the diagnosis since any idiot can read the Merck Manual.  That is why expert bootfitters will always be in demand.

 

Finally, it does seem odd when I have to explain to beginning/non-skiers that one should spend $500+ to get boots custom fitted by an expert, requiring a number of hours and iterations, even if their feet aren't unusually shaped.  It should be more like getting a pair of eyeglasses.

 

This is a matter of perception.  If novice skiers read in their latest ski magazine or free publication that going to an expert bootfitter is a given, they will go.  Unfortunately, most will not see the perceived value of a ski shop with an experienced bootfitter until it is too late.


 

 

post #53 of 58
Quote:
Originally Posted by quant2325 View Post

This is a matter of perception.  If novice skiers read in their latest ski magazine or free publication that going to an expert bootfitter is a given, they will go.  Unfortunately, most will not see the perceived value of a ski shop with an experienced bootfitter until it is too late.

 

 

^^^^^

Boot fitting is several categories more fun than tibial plateau fractures.  Also somewhat less expensive.

 

post #54 of 58
As much as I enjoyed the “ski boots hurt because boot makers hate us” discussion, it is also possible that the answer of at least why is because it’s a simple engineering solution.

Problem 1: How do we design a boot to stay off the snow as long as possible when the skier tips his skis, taking into account that this will also cut the edge of the ski below grade?

Simple answer: Make the boot as narrow as possible.

Problem 2: How to we design it to sustain incidental contact with the snow and to mitigate leverage or control points acting against the direction of travel of the ski?

Simple answer: Make the sides of the boots as parallel as possible.
post #55 of 58

check out the head raptors nice big toe box , the roomest I have seen.they have 3 different flexes 115 130 150  and you can get a foam linner!! I have narrow heel and a fat fore foot also foam linner is the only way the go!!!!  heat fit linners do cut it.  get the right flex.  A 2 piece shells deliver more power in every type of terrian period.  3 piece shells ski from the upper leg not the ankle, no ankle no skiing.

 

sam

post #56 of 58
Quote:
Originally Posted by sofort99 View Post

As much as I enjoyed the “ski boots hurt because boot makers hate us” discussion, it is also possible that the answer of at least why is because it’s a simple engineering solution.
Problem 1: How do we design a boot to stay off the snow as long as possible when the skier tips his skis, taking into account that this will also cut the edge of the ski below grade?
Simple answer: Make the boot as narrow as possible.
Problem 2: How to we design it to sustain incidental contact with the snow and to mitigate leverage or control points acting against the direction of travel of the ski?
Simple answer: Make the sides of the boots as parallel as possible.


I don't see these problems as being that massive of an issue as 99% of skiers will not ski in a manner where this will occur. That being said you would think that boot makers would have started catering to the majority years ago. Thankfully they are starting to see that my just because people have wide feet does not mean they don't want high performance boots.

 

post #57 of 58
Quote:
Originally Posted by Old Boot View Post

Oh Joy!!!! I thought it was my feet that needed fixing!!!

 



Imagine how I feel right now hissyfit.gif

post #58 of 58

If it was as cheap and easy to make a boot mold as has been suggested. then Jarden Corp, owner of K2, Volkl, CrockPot, Mr Coffee, Coleman, etc...would have "build your own custom boot" stands in every Dick's just like Dr Sholes has a "custom orthotic" center in every pharmacy.  Instead, they own Full Tilt.  Modern spin on a 40 year old design.  K2, Volkl, and Line...Jarden's ski brands, have over 50% of the alpine ski market in the US...they are a consumer products company...don't you think an American mega corporation with those kids of resources would invent a better mouse trap if it was as cheap and easy as some of you seem to think?  They don't already own a pile of boot plants, they aren't sitting on a legacy program of boot designed based in the "1500's"   Its not some diabolical plan by angry european sadists...

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Ski Gear Discussion
EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Ski Gear Discussion › Fit versus Function, or Why Do Boots Still Hurt?