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Binding design question

post #1 of 16
Thread Starter 
I'm not sure how to form my question so let me start with my story.

On April 1st while finishing a line in West Bowl at Mammoth Mountain I blew out my knee. It wasn't from a fall, it was more of a caught edge that I was attempting to drive my weight through. I have it on video as my line was being taped for an annual ski movie I make (the movie is shots of kids who ski w/ me and typically just one segment of me at the end). The incident took place out of the bowl, in a relatively flat area, and at what I consider a slow speed. We're all a bit shocked by it. If I had been hurt rag-dolling down something sketchy it would be easier to rationalize...

Now for the damage - I have a completely torn ACL, grade II tear of my MCL, and tear in my lateral meniscus. I go in for surgery next week with my fingers crossed.

The setup has a pair of Look P12 bindings (with Pivot heels); the bindings are about 2 years old and had released recently; the DIN was set at 7; I weigh about 170 and am an experienced skier.

I've watched the video over and over. I don't understand why the binding didn't release.

While out and about in my knee brace I've had numerous people approach me with stories of ACL injuries. Lots of skiers and most claim to have been injured during what they describe as a "slow fall". So it seems like this is a typical injury scenario.

I'd sure like to understand why my binding didn't release. So I guess my question is do bindings fail to release during certain "types" of stresses? And is anyone trying to design a binding that prevents this type of injury?
post #2 of 16
First of all, I hope you have a good outcome with the surgery. I've screwed up my ACL and meniscus and it was not a good time.

Wish there was a simple answer to your questions. I've taken binding tech training and one of the things they stress is that bindings do not always release. If the forces on the foot are in a certain direction the binding may not release. (As you so painfully found out.) Also, if the binding is frozen it may not release. If your boot sole was not properly fitted to the binding there may be too much pressure on it and that can affect how it releases. (That is why you need to have all your bindings checked and adjusted when you get new boots.) There are many things that have to happen for the boot to release.

DIN settings are determined on a look up chart. They take your age, weight, height, and skiier type, look at the chart and bingo they get the DIN setting. You should always have your bindings tested at the beginning of the season. One thing they look for is if the DIN setting on the indicator is proper. Sometimes the indicator is screwed up and they need to adjust the setting accordingly.

I've gotten in the habit of using skier type -1 when getting skis set up. That way I get a much lower DIN setting. Also, I'll crank em DOWN myself if the tech won't do it. I'd rather the ski pop off too easily than not at all. I've not had a problem with this. I've never had a ski pop off at an improper moment. If you're guiding the ski properly you shouldn't be torquing your foot too much. I've had em pop in moguls but only when I screwed up.

Sure would like to look at the video and maybe get an idea of what happened. Maybe you could post just the unpleasant part.
post #3 of 16
Was it a slow forward or rearward fall? If it was a slow forward fall, the Look toe piece has a sliding AFD but does not have any downward compensation. IIRC, Salomons spheric toe is the only toe piece that incorperates downward compensation. The downward compensation is transformed into lateral force allowing the binding to release under slow forward twisting falls. FWIW, the "driver" toe piece aslo does the same thing for slow rearward falls too.

Say what you will about the toe wings losening up, IMHO, the Salomon Driver is the best binding out there.
post #4 of 16
Thread Starter 
I have a (admitedly dumb) move I've done in the bumps my whole life. While driving my left (downhill) ski across the face of a bump I push off, flare out my right ski while turning back left in the air and landing back on the left (now uphill) ski bringing the right ski back down onto the snow while shifting my weight to it.

On this occasion when the right ski came back down it hit funny and caught, I tried to power through it but my weight went back and the knee popped.

So to answer Phil's question I would call it a slow rearward fall.

T-Square, I'll try to see if I can host the video and post a link to it. The boots, bindings and skis we're all set up in a shop two years ago (all new). It's pretty ironic because they're the only new setup in my quiver. I have lots of demos I've puchased with questionable history.
post #5 of 16
The Din setting is designed to be specific to a certain amount of energy causing the release. If you are going slow, you just don't generate as much energy. Less energy=no release.

Slow falls are the most dangerous to your body parts. Fast falls or falls at high speed generate huge amounts of energy you need a higher setting (din) to keep from pre-releasing. Experienced skiers skiing slow are probably at the highest risk (other than beginners)

When I'm teaching I tend to keep my binding set pretty low for this reason.
post #6 of 16
Bindings aren't designed to protect knee ligaments. There are ways to do that sort of damage to yourself while applying minimal load on the bindings. The following site has been linked here before but here it is again:

http://www.vermontskisafety.com/faq_...iers_menu.html

It sounds like you were in a 'phantom foot' type scenario. Your funny technique puts funny loads on your knee and this one time you went too far. It is just unfortunate, but I hope you have a good recovery.

Edit: I am sure there are some doctors or researchers who would be interested in studying your video.
post #7 of 16
Good luck! We all hope the surgery goes well.

Let's face it. Weird things happen while skiing that no single piece of equipment can compensate for. For example, several years ago, my wife was skiing down the end of a run. She had to make one quick correction for a guy who crossed in front of her. Nothing violent. No loss of control. Still standing.

When she stopped, she told me she had bad pain in her ankle. I took her into the Patrol room. They splinted her foot and off to the emergency room we went.

End result. Her ankle was broken. When her ankle broke, the tendons torqued and broke both her leg bones. She got a cast and 6 weeks to heal.

Never fell. Nothing. So, go figure.
post #8 of 16
Quote:
Originally Posted by Atomic_918
Good luck! We all hope the surgery goes well.

Let's face it. Weird things happen while skiing that no single piece of equipment can compensate for. For example, several years ago, my wife was skiing down the end of a run. She had to make one quick correction for a guy who crossed in front of her. Nothing violent. No loss of control. Still standing.

When she stopped, she told me she had bad pain in her ankle. I took her into the Patrol room. They splinted her foot and off to the emergency room we went.

End result. Her ankle was broken. When her ankle broke, the tendons torqued and broke both her leg bones. She got a cast and 6 weeks to heal.

Never fell. Nothing. So, go figure.
:
I figure she should get her doc to check for osteoperosis.
post #9 of 16
Below are some other interesting links on PHANTOM FOOT ACL. There is a good possibility that you injuried the ACL in a previous fall possibly weeks prior to the injury. For example my son's knee was scoped and has a 70% tear in the ACL. He is a recreational skiers about 10 times a year with the 70% tear. Obviously he is much more at risk then anyone else and the only reason he knows his ACL is torn at this point is because they cut open his knee and looked at it after his car accident about 6 years ago.

http://factotem.org/library/database...SM-Sep95.shtml

You may want to contact the guy that runs www.ski-injury.com. I bet he would love to see your video.

Check out http://www.ski-injury.com/lrn3.htm#Bindings

As you probably know but for everyone else, most important is never never have you hands low and in back of you. Make believe you are reading a newspaper or anything else that helps you keep you hands out in front of you. You can never be too far foward unless you fall.
post #10 of 16
Quote:
Originally Posted by Ghost
:
I figure she should get her doc to check for osteoperosis.
She was in her 20s at the time. Thanks.
post #11 of 16
Quote:
Originally Posted by bobski
I'd sure like to understand why my binding didn't release. So I guess my question is do bindings fail to release during certain "types" of stresses? And is anyone trying to design a binding that prevents this type of injury?
Bobski,

shoot me an e-mail to repsamples@verizon.net and I can probably put you in touch with someone who can shed some light on your situation.

coup
post #12 of 16
Good Luck Bobski. I hope the surgery goes well, that your recovery is complete, and that you're out on the slopes again soon.
Injuries of this sort are something we all dread but try to block out because they can happen to any one of us on any given day.
Look P12 bindings are some of the better ones out there but unfortunately, injuries can occur with any equipment.
I, like so many others, have probably fallen more over the years while going slow on flat terrain.
Don't drive yourself crazy trying to over-analyze what happened, just devote your energies to your recovery. Get well
post #13 of 16
Afaik, recent bindings work best when dealing with dynamic situations, i.e. when the force applied does not last more than approximately one second.
In slow-speed falls the force applied takes more time but due to the unsufficient speed the resulting impulse is often not sufficient for the binding to open properly (that´s what David already said).

Another sad truth is that the bindings "know" how to protect the "hard parts" (bones) but are by far not so good at saving the "soft parts" (ligaments) - that´s again what kiwiski said.

Watching the video some expert might find out some more or another reasons.

There´s often the dilema: should you get down your DIN setting when skiing slow (with kids, a beginner, teaching, etc.) or shouldn´t you touch the setting you have from the shop?
post #14 of 16
Thread Starter 
I'm 2 days post-op and doing well. I've sent my video to ski-injury.com and some reps from rossignol and dynastar.

When I watch it I really think it should have released. I'm also inclined to believe that with appropriate R&D a binding could be developed that would prevent these "slow fall" injuries. But I've been a high tech exec my whole career and have been paid to never accept the "can't be done" answer...

I'll probably lower my DIN next year. I've pre-released before and I find that a whole lot easier to deal with.

Oh well - on the road to recovery...

My web site won't allow me to easily host a .wma file. If anyone would like to see it it's 3mb. Just let me know. (Or if you know how to convert .wma to .mpeg let me know and I'll host it).
post #15 of 16
Quote:
Originally Posted by Atomic_918
She was in her 20s at the time. Thanks.
Sorry.
It's not likely to happen at 20, but nothing's impossible, kind of like not checking for breast cancer in men. But I digress. Obviously it was an isolated incident and hence there was no need to check for osteoporosis. It wasn't like she was braking bones right left and center every other week.

BTW My mom (who had OP) suggested I get checked out for it; I kept braking bones every time I fell of a motorcycle. I thought about telling her it was normal to brake a bone or two when you bounce through a pothole at over 100mph, but I thought better about it.

Bobski,
I wish you a speedy recovery and a happy ski season next year.
post #16 of 16
Quote:
Originally Posted by bobski
I'm also inclined to believe that with appropriate R&D a binding could be developed that would prevent these "slow fall" injuries. But I've been a high tech exec my whole career and have been paid to never accept the "can't be done" answer...
It could be done, sure.
The problem is how much it would cost and if the companies involved are willing to put the money into it.
The first electronic binding (a Marker) was introduced at the Munich Show 25 years ago. It never made the production: afaik, because of unsatisfactory source of energy and because of the price (was said to be about 800 German marks then, more than the most expensive skis).

Good and fast recovery!
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