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Knee Bindings - Page 3

post #61 of 91
Quote:
Originally Posted by jdistefa View Post

the 'inward twisting' component of the injury mechanism - from the rut/bump picking up and redirecting the ski very rapidly - probably overwhelms the capacity of any mechanical binding to react in enough time to protect the knee.

....

Lastly, IMO there's some woefully ignorant crap on this thread re. biomechanics, physics, injury mechanisms, and equipment.

And what are your particular qualifications in mechanical design and multibody dynamics that led you to the conjecture above?

 

FWIW, the conjecture present in that first statement comes dangerously close (if I'm being polite) to what you are complaining about in the latter.  The statement you made is suspect until proven otherwise with analysis, and it wouldn't be a simple analysis.  I'll leave that up to people designing bindings for a living.  I just enjoy the fruits of their work.

 

I made a post earlier using "twist" with scare quotes, and Jim responded with a rant about how wrong I am using twist without any such scare quotes.  The level of discourse here is certainly pretty low; I'll agree with you on that.

post #62 of 91
Quote:
Originally Posted by rick howell View Post

Reply to "Beyond" --  These refs are based on the scientific work of literally hundreds of medical-engineering researchers over decades of focused work.  I'm sorry, but many of your points are incorrect and not based on proven science.  The main error in your post that must be corrected pertains to the prevalence of ACL injuries:  skiing ACL injuries are BY FAR the #1-injury in skiing, and they have been the most prevalent for 20 years.  TAgain, it is important for all of us to get our facts correct (based on real science) before we post.  Let's be good to our sport.

 

 

Rick, you're not the only one who cares about this sport. Nearly every estimate I've seen states that MCL's are the most common ski knee injury overall, and that ACL's appear to run slightly below this. Now you have an interest in claiming most injuries are ACL's. Great. Go for it. But part of the problem in making any estimate is sampling error - A lot of lower grade "sprains" of the MCL do not require medical intervention, and/or the skier simply self-treats. (Yes, there are articles about this too.) But from an epidemiological standpoint, it's still an injury. ACL's by contrast, usually end up at the docs, and get reported. Obviously they tend to be more severe. I've also noted bizarrely wide confidence intervals for estimates of ACL, suggesting that a lot of the estimates are just that, and not based on random or large samples. So excuse me if I don't buy your cited numbers, or go running around screaming about how we must have new bindings, but that doesn't mean I'm "spreading incorrect information." It means I am more cautious about statistics than you are. 


Look, I appreciate your enthusiasm, I certainly cannot ignore your self-confidence, and I appreciate your bioengineering perspective. But try to calm down, and stop bulldozing people who have different perspectives; you're sounding like a paternalistic religious practitioner, only you talk about "scientific" like it was some kind of universal truth claim. Wrap your head around the idea that some of us are scientists, we come from different paradigms, with different relevant questions and appropriate answers. My paradigm doesn't think engineering approaches are the ultima thule for the world, however cool they are. That's all. Contrary to your description of the capacious literature, I have found it to be thin, the epidemiology more so, most of the "studies" are on very biased samples. Perhaps we have different definitions of what constitutes a study, or maybe we scrutinize different fields. Orthopedists with whom I am in touch agree with my version of reality, FWIW. So your summations/citations of the (to me) already questionable lit appears to be understandably, enthusiastically, self-serving. More to the point, If I chose to, I could methodologically pick apart ANY of these studies, yours or anyone else's, pro or con to your POV, in nearly any relevant field (it's a standard academic sport). I just have better ways to spend my time indoors.  Gotta go. And yeah, let's be good to our sport...

post #63 of 91

With experience like YoMomma's, this binding better get better constructed or it will disappear very quickly.  DIN adjustment screws that strip? AFD's that fall out? (anti-friction device)

Forget $700k's of studies, the above issues will kill it.

 

Do not most binding studies reveal the critical importance of AFD's?

 

Quote:
Originally Posted by Yo Momma View Post
 

I tested these bindings extensively during the last month or so. I found the interface between the binding and user in need of serious attention. I was losing one AFD per day of skiing. The factory quickly addressed the issue with a redesign on the heel and the new design has no AFD at the heel. However this introduces an entirely new problem in that if the heel now just has a plastic interface which was not in the original design, and is not smooth, will it still release as predictibly as the teflon AFD in the original design? Only time will tell.......

 

I was informed by the manufacturer that the toe AFD is more of a critical release issue. I eventually ended up losing a toe AFD and the factory said that there was nothing they could currently do with the design. It would be addressed in the future. They quickly replaced the toe AFD and entire toe plate, after hours. Their service was excellent and they seemed genuinely concerned about my experience. I went home and was able to peel up the new toe AFD with a short pull from a blunt fingernail. The AFD is an issue that needs attention. 

 

I pre-released once when I gained enough confidence in the binding to push them hard on my Mantras. My standard setting has been 8.5 for years and I run Marker Comp 14.0 on two sets of Mantras (184/177) and have never experienced a pre-release even during 10'- 20' drops off cornices. I've crashed and released (thank God, but never pre)

 

These replaced my Markers and the heels  were set at 9.0 The heel was the source of the pre-release and  I attempted to crank up the heel with a large 6" Stanley screw driver (It's a big screwdriver) in excellent condition to finish out the day......the heel adjustment screw is plastic and promptly stripped w/o moving and I could no longer make an adjustment. I've adjusted the Markers, Sollies, Freeflexes with out an issue in the dead of winter on other sets of skis.

 

For the price these bindings need to be bulletproof. They are not. I found them unreliable because if you travel with them and you have no extra toe AFD's in your pocket or in your car, you'll have to rent skis to finish out your day or possibly your trip. If you're hiking on a one way trip to the top of a cornice and happen to notice it gone.....you're hosed..........that is a MAJOR problem.......especially if you cannot get down via easier terrain.......

 

 

Knee binding is on the right track but need more R&D in the boot interface department...........

 

post #64 of 91
Quote:
Originally Posted by Garrett View Post
Quote:
Originally Posted by jdistefa View Post

the 'inward twisting' component of the injury mechanism - from the rut/bump picking up and redirecting the ski very rapidly - probably overwhelms the capacity of any mechanical binding to react in enough time to protect the knee.

....

Lastly, IMO there's some woefully ignorant crap on this thread re. biomechanics, physics, injury mechanisms, and equipment.

And what are your particular qualifications in mechanical design and multibody dynamics that led you to the conjecture above?

 

FWIW, the conjecture present in that first statement comes dangerously close (if I'm being polite) to what you are complaining about in the latter.  The statement you made is suspect until proven otherwise with analysis, and it wouldn't be a simple analysis.  I'll leave that up to people designing bindings for a living.  I just enjoy the fruits of their work.

 

I made a post earlier using "twist" with scare quotes, and Jim responded with a rant about how wrong I am using twist without any such scare quotes.  The level of discourse here is certainly pretty low; I'll agree with you on that.

 

FWIW,  I tore one acl so quickly that I doubt a binding could've helped. I was going fast downhill on 193cm gs skis and the tip of the ski dropped in a hole and shot sideways. I was launched in the air flying downslope parallel to the trees.  In the air I remember thinking "Sh## this would be fun if my knee wasn't shot"  The acl tear was close to instantaneous but with no "pop".

 

Shorter skis may help though.

post #65 of 91

Mr. Howell:

I don't get it. Where is this wealth of research? I read one paper (that you consulted on) that tries to explain ACL injuries in skiing using a 3D computer model. (I have access to the journals through the the university). This is peer reviewed, but that essentially means: if your model is correct then you are right. Is this model correct? I don't know, neither do the authors. I read the abstract you presented at a conference explaining the binding. What does this show? I went to pubmed and read up on ACL injuries in skiing. Not too much there beyond epidemiological data. One article suggest that (as I had thought) a boot with a releasable back cuff might help. At least that study used people.

 

Does your binding work? Maybe. Should more work be done on preventing ACL injuries? Definitely. Will I be buying the kneebinding? Not from a company that can't get a little AFD to stay on.

 

One thing I am sure of is that if the kneebinding proves effective, the technology will either be licensed or stolen by other manufacturers. However, I suspect that more research will in fact show that modifications in boot design (even simple ways of better controlling canting, lean, and flex) may be the best bet.

post #66 of 91

brw, the links to those articles didn't work. I saw it on the Knee Binding Site.

Have to agree with aschick as far as the articles go.  That in itself doesn't necessarily mean all that much other than you can't claim the moon with them.

 

It's not a given that technology that is safer is picked up by manufacturers.

A good example is SawStop. These guys invented a way to stop a running table saw blade in a fraction of a second using air bag technology.  It worked, they built it and demonstrated it with hot dogs. They went to every manufacturer of saws.  All thought it was brilliant.  None of them wanted it. Why? Well I guess it's because if they put it on one machine, now they have to put it on all of them because of law suits.  You're admitting they're unsafe. Gee, no one knows that?

 

They started making their own saws with the device.

Link to their product:

http://www.sawstop.com/howitworks/how_overview.php

post #67 of 91
Quote:
Originally Posted by Garrett View Post
Quote:
Originally Posted by jdistefa View Post

the 'inward twisting' component of the injury mechanism - from the rut/bump picking up and redirecting the ski very rapidly - probably overwhelms the capacity of any mechanical binding to react in enough time to protect the knee.

....

Lastly, IMO there's some woefully ignorant crap on this thread re. biomechanics, physics, injury mechanisms, and equipment.

And what are your particular qualifications in mechanical design and multibody dynamics that led you to the conjecture above?

 

FWIW, the conjecture present in that first statement comes dangerously close (if I'm being polite) to what you are complaining about in the latter.  The statement you made is suspect until proven otherwise with analysis, and it wouldn't be a simple analysis.  I'll leave that up to people designing bindings for a living.  I just enjoy the fruits of their work.

 

I made a post earlier using "twist" with scare quotes, and Jim responded with a rant about how wrong I am using twist without any such scare quotes.  The level of discourse here is certainly pretty low; I'll agree with you on that.

I edited my post several times to tone down my response.  Don't bother pretending to be polite .

 

If you read my post, I did say probably overwhelms the capacity of the binding.   There are very few certainties with this stuff given the variables involved.  Rick's design is based on good bench science and a very solid understanding of the typical injury mechanisms involved.  How well the design works in the real world will require data collection of a type that will probably not be done (open to hear from Rick on this point) - hence my earlier comment about efficacy vs. effectiveness.

 

The example I cited is rare, and tends to occur among elite skiers at high speeds.  Once you treat (well, not you) a few of these guys/gals and review their videos, it's painfully obvious re. what happened to their knee.  As Rick referred to, the typical combination of loading that ruptures the ACL is a triad of backward position, valgus stress, and internal rotation.  What I (and others) believe happens in these specific cases is a very sudden and large internal rotation load on top of some degree of rearward position and valgus knee stress from the act of skiing (i.e. angulation).  Essentially these athletes give themselves their own 'pivot shift' maneuver (I'll leave that up to you to google).  There just isn't good clinical 'science' on this stuff, but there is expert opinion (and experience) which has some value IMO.

 

If I recall, you were the same guy that was pontificating about F1 vs. World Cup medical coverage.  Carry on .

 

 


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post #68 of 91
Quote:
Originally Posted by Tog View Post

brw, the links to those articles didn't work. I saw it on the Knee Binding Site.

Have to agree with aschick as far as the articles go.  That in itself doesn't necessarily mean all that much other than you can't claim the moon with them.

 

It's not a given that technology that is safer is picked up by manufacturers.

A good example is SawStop. These guys invented a way to stop a running table saw blade in a fraction of a second using air bag technology.  It worked, they built it and demonstrated it with hot dogs. They went to every manufacturer of saws.  All thought it was brilliant.  None of them wanted it. Why? Well I guess it's because if they put it on one machine, now they have to put it on all of them because of law suits.  You're admitting they're unsafe. Gee, no one knows that?

 

They started making their own saws with the device.

Link to their product:

http://www.sawstop.com/howitworks/how_overview.php


 

Amazing invention!!! 

post #69 of 91

My comments are in Bold.

Quote:

Originally Posted by CHRISfromRI View Post

SierraJim: As I said before, I think we can agree to disagree here! In the future, please do not copy and paste my words. I write them cogently and efficiently, and do not appreciate others chopping up my thoughts, to juxtapose them and suit their puropose. If you have a problem with what I say, then just say it in your own words - that is if you can!

This is called quoting. Get a grip. Why would anyone repeat what you just said.

Yes I've chopped you're words up so we can look at them. Sorry for the inefficiency. The only way forward with this post is Chop Suey.

 

Furthermore, SierraJim has now confirmed for everyone how eminently unqualified he is to be spouting opinions on this product, as it is now so painfully obvious that he has clear financial ties to competitors of this product - through the products that he reps or is somehow involved with.

Just the opposite has been confirmed here.  SierraJim has stated quite clearly his involvement with Look:

"I am a retailer not a product rep. It happens that I was the N.A. product manager for LOOK in the period '93-'97. During that time I spent significant quality time with both Carl Ettlinger and David Dodge and more than significant time in the product lab in Nevers France. The upshot of that experience is that I have a pretty fair understanding of the forces that are at play in knee injuries" - Sierra Jim post #33

What about that is confusing? Clearly there's no financial stake here.  We have little doubt about Sierra Jim's motives.  Yours are becoming interesting.

 

I alluded to these ties earlier as something that should be made clear uo front to readers so that they may understand a writer's frame of reference - and now down the road the fact that SierraJim's has these ties is patently clear to everyone else.

Now your cogent presentation has turned to...well irrelevant nonsense. Apparently you're not speaking for "everyone" either.

 

OTOH, I am simply a Kneebinding customer and I have personally used this product for 19 ski days and over a half million vertical feet, and as such actually have an opinion on this product that is useful to others.

It was useful in the begining, currently these thoughts are not. What's up with the vert count? Are you heli-skiing at Waterville Valley, NH? Didn't know they had that there.

 

To be sure, I'm going to go out right now to ski my 20th day on Kneebindings, and my 34th day this season since ACL reconstruction last season!

Congrats. This means what? I've had probably 300-500 days since Acl reconstruction.  Should I promote the long underwear I've been using?  I think they've helped. Really. 

 

 Rick Howell: We have never actually spoken before, but thank you very much for jumping in to set the record straight!

Nothing in the record was 'bent'  but thanks for posting Rick!  We do enjoy real information.

 

post #70 of 91

Deleted per court order.


Edited by rick howell - 4/2/2009 at 09:59 pm
post #71 of 91

Holy mother of all posts! I left it on auto scroll and it was like watching a waterfall.

I'll take a look at it...

In the meantime, how about this "greater edge control" ? Where does that come from?  Wider mounting, more secure grip of the boot?

post #72 of 91

(Picks up jaw)   That has got to be the worlds longest post, I didn't think that was possible in a forum.  Ill need a few days for this one.

post #73 of 91

Tog:

 

Allow me to help you with some basic math. 2000' vertical X 20 runs per day X 21 days = 840,000' vertical.

 

The point about greater edge control seems valid to me as I have experienced this first hand for 21 ski days of great skiing. I'm not sure about the science behind it but it is probably related to there being a decent ramp angle, and riser height allowing excellent edge leverage. In any case, I know what I feel when I'm skiing. Maybe it's time for a little more emphasis on actual testing than hypothesizing (a form of bench racing). To be sure, I'm a very strong skier putting these devices through their paces and objectively reporting the results, while you sir are simply spouting vapor.

post #74 of 91

Chris,

 

It would be nice if you can share some pictures.

 

 

post #75 of 91

Chris,

 

It's great that you're enjoying the bindings, but please take a stats course.

post #76 of 91
Quote:
Originally Posted by CHRISfromRI View Post

Tog:

 

Allow me to help you with some basic math. 2000' vertical X 20 runs per day X 21 days = 840,000' vertical.

 

The point about greater edge control seems valid to me as I have experienced this first hand for 21 ski days of great skiing. I'm not sure about the science behind it but it is probably related to there being a decent ramp angle, and riser height allowing excellent edge leverage. In any case, I know what I feel when I'm skiing. Maybe it's time for a little more emphasis on actual testing than hypothesizing (a form of bench racing). To be sure, I'm a very strong skier putting these devices through their paces and objectively reporting the results, while you sir are simply spouting vapor.

Thats almost as long as that post. 

Bringing World Cup caliber ski equipment and service to all skiers - from pro ski racers to everyday all mountain skiers and into the...

Reply
post #77 of 91

Deleted per court order.


Edited by rick howell - 4/2/2009 at 10:00 pm
post #78 of 91

Rick's innovative contributions to skiing and cycling are greatly appreciated. Here, his patience with our questions and criticisms is even more remarkable.  Something new is not inherently good or bad but almost always worth considering.  I called Rick last year upon learning of Kneebindings and he was kind enough to take the time to inform me of the benefits of his product.  I look forward to giving them a work out.

EJ Levy

 

post #79 of 91

Here are two things I came across today.

 

First is a device that can be implemented for powering up an electric binding system:

http://intelligensports.com/2008/02/08/biomechanical-energy-now-ready-for-prime-time/

 

 

The second is for a new binding system by Carl Ettlinger:

 

http://v3.espacenet.com/publicationDetails/originalDocument?CC=US&NR=2008036180&KC=&FT=E

post #80 of 91

Deleted per court order.


Edited by rick howell - 4/2/2009 at 10:00 pm
post #81 of 91

Update on my Kneebinding Experience

 

I am up to 27 ski days on my Kneebindings (of my 41 total ski days so far this season), by an expert skier in all conditions and on all terrain. Still NO pre-releases, NO knee injuries, NO bone breaks, just GREAT skiing!

 

Also, my wife and sister-in-law have around 15 ski days on their Kneebindings, also with NO pre-releases, NO knee injuries, NO bone breaks, just GREAT skiing!

post #82 of 91

Good news Look, Fritschi, and Dynafit fans!

 

Today I hit 112 days for the season about half of those days are on Look PX18's set at 14, I've had no pre-releases and no knee injuries.  My Fritschis and Dynafits are are at 12 and again no pre-releases, no knee injuries just great skiing!  Apparently based upon this highly scientific data setting your binding way too high and using Look, Fritschi, or Dynafit is also good for the knees.

 

I've also lost no binding parts and had nothing whatsoever break on any of my bindings.  The only negative I have to report is that while wearing Smartwool base layer and an Arcteryx Sidewinder I didn have a minor shoulder seperation when I misjudged a pillow top landing. I'm ok now but I don't think I can ever use those items again as they clearly caused the injury!

post #83 of 91

Define "minor shoulder separation" so we can judge the performance of the jacket er..binding. It might fall within the performance criteria.

post #84 of 91

Type I separation.  Skis and bindings had nothing to do with it either.  I completely misjudged the size of the pillow top I wanted to land on.  The snow made it look larger than it was, skis hit snow, then air as I missed the landing.  My shoulder smacked hard against rock and popped.  I fell a few feet further than I anticipated but only tore my jacket and popped the shoulder.

post #85 of 91

 

Quote:
Originally Posted by CHRISfromRI View Post

Update on my Kneebinding Experience

 

I am up to 27 ski days on my Kneebindings (of my 41 total ski days so far this season), by an expert skier in all conditions and on all terrain. Still NO pre-releases, NO knee injuries, NO bone breaks, just GREAT skiing!

 

Also, my wife and sister-in-law have around 15 ski days on their Kneebindings, also with NO pre-releases, NO knee injuries, NO bone breaks, just GREAT skiing!


hey i am coming in here really late, but i was asked by someone to look into this binding, only comment i can make on the above is i have skied several hundred days ove the past few years, on an assortment of bindings, currently i have had NO pre releases, NO knee injuries and NO bone breaks, I too have had some great skiing
 

post #86 of 91

My sisters husbands brothers friends neighbor skied with a guy that also knew a person who once saw an ad for these miracle bindings.....no pre releases, injuries or broken bones were found anywhere.

 

I think this now has me thinking about this in a completely different way

post #87 of 91

CEM: If you're post is sincere, I have now skied 47 days (of 61 total ski days) on Kneebindings so far this season coming off an ACL reconstruction early last Spring. They're more expensive than most other bindings, except maybe the Marker Duke, but in my case cost wasn't even an object if there was even a chance that the Kneebindings could help mitigate the possibility of a re-injury. There is a video link on my profile to them being skied.

 

I would suggest calling the company on the phone and talking with them about their latest improvements.

 

So - with that out of the way, I guess now the flaming can start all over again...

 

post #88 of 91

 

Quote:
Originally Posted by CHRISfromRI View Post

CEM: If you're post is sincere, I have now skied 47 days (of 61 total ski days) on Kneebindings so far this season coming off an ACL reconstruction early last Spring. They're more expensive than most other bindings, except maybe the Marker Duke, but in my case cost wasn't even an object if there was even a chance that the Kneebindings could help mitigate the possibility of a re-injury. There is a video link on my profile to them being skied.

 

I would suggest calling the company on the phone and talking with them about their latest improvements.

 

So - with that out of the way, I guess now the flaming can start all over again...

 


perfectly sincere, and factual,alas i have never required ACL surgery, but i have had various ligamentous injuries over the years, mostly as a result of impact during big falls racing.  i see technology like this coming and going time and time again, does this work? maybe, is it better than what is out there? possibly, is there a market for this product? probably
 

 

i guess the big question is only one that can be answered by the consumer...and is a matter of evaluating risk what is the risk of me injuring my knee [or repeating a previous injury] and how much am i willing to pay to reduce that risk..because however much anyone wants to argue it, YOU CANNOT totally eliminate the risk.

 

enjoy your bindings, but being brutally honest i don't see too many shops jumping into this big time in the forseeable future..... time will tell

post #89 of 91
interesting thread.

there are two new terms for me here.
1)could someone provide a link or meaning to BIAD?
2) "deleted by court order"?

also, could someone explain why the tyrolia diagonal heel doesnt provide whatever additional release that the knee binding claims?
post #90 of 91

Knee Binding Review

                                                               

Me:

150 lbs., 5’-7”

Masters ski racer

Mechanical engineer

 

I tore my ACL tendon 4 years ago.  I had it repaired with a patella tendon graft 2 years ago.  I have been waiting for the Knee Binding as it seamed like cheap insurance.

 

I had the bindings mounted in January 2009 to a pair of Stockli GS skis.  My first impression was that they clamped the ski to the boot more rigidly than other bindings.  At first this was un-nerving as they seemed much less forgiving, but I soon became used to the feeling.

 

The first time skiing, I lost all 4 anti-skid pads because I was taking the skis off each run to ride the Keystone gondola at night. The Company has not come up with a fix for this yet, but they have changed the heal so that the anti-skid pocket is now filled in with plastic.

 

My second time skiing I was hit from behind by a snowboarder (who didn’t bother to stop) and knocked me out of one ski.  That toe binding twisted past its normal limits and slightly damaged the plastic housing.  (Would not have had damage if it was aluminum)

 

Update after 11 days skiing in Chile and 35 days total:

 

I was skiing with the bindings set 1.5 din settings lower than my race setting, 7.5 versus 9.0 in an attempt to avoid potential knee injuries. I had an upward heal pre-release skiing fast through moguls.  I don’t think this was the fault of the bindings, just too low a setting for my skiing.  I have yet to have a fall where the bindings released sideways at either the heal or the toe.  I can twist out though with some effort.

 

I have had two additional problems with the bindings,  I began stripping out the plastic screwdriver slot adjustment on the heal when adjusting with a slightly undersized screwdriver.  I was surprised, as this has never happened with metal adjustment screws.  When taking the skis off, the brakes are no longer deploying.  In a fall with release, I am fairly certain the brakes would no longer deploy properly.  The brakes have worn a groove into the plastic housing preventing them from deploying.

 

While I like the concept of these Kneebindings, I cannot recommend them until the problems with the antiskid plates, the plastic adjustment screws and the brake deployment are fixed. 

 

I hope the company is moving rapidly to fix these problems. It would be great if the company would make a public statement explaining how these problems have been or will shortly be fixed.

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