GatorMod & Crushing Falls (moved from OB4 Review)

[maddog]

Well he will go for a MRI on July 1st so we can find out the inner details, he does heal quickly, youth . What are the opinions on the Conley stealth system? It seems similar, I like the boots, it also is a dbl pin system. I currently ski ho s2 with dbl animal bindings and feel confortable in them . Water skiing in NH is a fairly short season it sucks to get hurt anytime, he will heal but may not compete again. bummer

[gator1]

@maddog‌ As a fellow ankle injury victim, 2 years in and still rehabbing, sorry for your son. It SUCKS.

 

But, he has provided us with some key data. He had a crushing OTF skipping over the ball. His binding released, but still trashed his ankle. So far, old story, repeated almost weekly here on BOS.

 

BUT.

 

His binding system released, and he bent the bar under his boots. This means that his front foot was planted so hard that even after the rear of the HO system released, his front foot stayed on the ski with so much force that his rear foot BENT THE BAR TRYING TO LIFT the front .

 

Big strong kid has given us the critical piece of data to analyze the fall. Us old guys just rip our foot up, but aren't strong enough to leave evidence.

 

What planted his front foot so hard? G forces of the ski decelerating crushed him down over his front foot. A release CANNOT save you in this situation. You can be standing on the ski in a tennis shoe, and once the perfect storm crushing OTF g forces are crushing you on your front foot, you are going to mash your ankle.

 

Nothing, no matter how good it is, that RELEASES, will save you in this rare perfect storm fall. You need something that EJECTS you off the ski.

 

You need a plate strong enough to pry your front foot off the ski, acting as your adjunct Achilles, and you need something to lift that plate. That's what gatormod does.

 

BTW, I believe this rear-foot-trying-to-help-front-foot is what happens to all the Velcro on plate guys who get hurt, but we can't prove it since the plate is flexible and leaves no evidence after it bends during the fall..

 

And, @maddog‌, please examine your statement "comfortable in them". That is almost word for word what my buddy said when sticking with his bindings he'd used for years. He ruptured his Achilles after 5 yrs in them, last Sept. Listen to @Its_Fun‌. At least get some OB4s or Stradas. They'll narrow the window in which you can get hurt.

[gregy]

I think in a crushing fall like @gator1 is describing the OB4 might have an advantage over the Exo, at least on the front foot anyway. My thought is that with the OB4 system there is a spring loaded release in the front where on the Exo it is a solid mounting attachment. I think with OB4 there might be enough forward force to cause the release spring in the front to compress and release. Any forward pressure on the Exo will force it harder into the front mount? But as gator says the foot is planted so hard not sure if it would help?

[maddog]

This is some great info, I am learning boat loads. I am attaching a photo of his binding, you are right he had a perfect storm that day he is a right foot forward 1-3-5 is our weak side. Thanks for the thoughts @gator1‌ this pic should help

[mmosley899]

@gregy you are correct in you thoughts about OB4, they will release in that situation. Both feet on one plate is a problem.

[gator1]

@maddog‌ great pic. think how hard that front foot was planted, how far both knees were jammed forward, and how hard your son's back foot was pulling up on the heel of the front foot AFTER the binding released to bend that thing. Without the bar/plate helping to pry his front heel off the ski he'd probably have done even more damage

 

Makes me a little sick to my stomach to look at it. Like my damn x-rays and the video of my buddy screwing my tendon back onto the top of my heel.

[gregy]

The plate bending probably saved his rear ankle. Look at plate in front, looks to be bent as well.

[gator1]

@gregy‌ You could be right. But, statics, dynamics, and beam loading theory would suggest that bend between the two boots, and the smile under the front of the front boot, is caused by a point load centered under the heel of the front boot, and a lifting force centered under the ankle of the rear foot. If the rear ankle was under a significant moment (experiencing significant torque) with not much lifting the smile would not be in the plate at the toe of the

front boot.

 

Additionally, I don't think that the rear ankle could exert enough torque via Achilles and Peroneal tendon to bend the bar.

 

I did some experiments with cadaver lower legs back in eng school, we bolted the foot to a base and measured torque until we heard tendons ligaments ripping and measured sharp increase in displacement, indicating catastrophic failure. I've never tested an HO to yeild point, but my opinion is torque from the ankle couldn't do it.

 

Tension, ie the foot pulling up on the rear plate as madpuppy pivoted over the front foot, seems like a more possible answer. And the joint can take quite a bit of tension.

 

And if that is the case, his rear ankle wasn't in much danger, plate bend or not. But, no disrespect to your opinion, I can't prove mine.

[gregy]

@gator1‌ no problem, great topic. I see your point of the heel lifting. @maddog sorry to drag out you son's misfortune here but in the interest of understanding the mechanics of the failure. Does he feel he damaged his front Achilles tendon or calf muscle. Did his knees drive forward during the impact with the water or was his legs straighter.

 

I think maybe a combination of heel lift and torque. My thought is that if it was pure rear heel lift the bend in the beam would have been under the rear heel. The bend is clearly under the ball of the rear foot which is the pivot of the torque when force is applied at the knee. If there was a torque on the rear foot it would result in a down force at the pivot point and a torque applied from the bend forward. These together would actually push the plate down harder against the ski (from the pivot point forward).

[maddog]

Unfortunately as I was driving the boat I did not see the fall and his girlfriend cannot go into details as she is a beginning skier. I did ask tonight about Achilles or calf pain and he said has some tender area on the calf but other is fine. For being a little more than a week after the fall he is putting a lot of weight on it but he has a high tolerance to pain sometime not a good thing. He has a MRI on ute and we will learn if anything it torne we know that there are no breaks. Wish we had the camera rolling like the 1st time

[MattP]

This discussion was created from comments split from: OB4 Systems Review.

[MattP]

@maddog‌ @gregy‌ @gator1‌ @Than_Bogan‌ I split these comments out of the OB4 Review as they were not pertinent but it was a good conversation. Lets keep it going!

[Than_Bogan]

Thanks. Might be a bit much to ask, but any hope of splicing in the stuff that I brought out to another thread? It kinda all belongs in one place.

 

Not worries if not. We'll find it!

[MattP]

@Than_Bogan‌ here is the other thread Understanding Crushing OTFs

I do not have the admin ability to merge threads I believe @Horton can do that

[Horton]

Thanks @MattP‌ keeping threads on topic really helps

 

@Than_Bogan‌ I could but then I would have to read it all

[Horton]

@Than_Bogan‌ you just want this thread and the other about crushing merged?

[Than_Bogan]

@Horton Yeah, but not at all a high priority. If trivial, then great. If not, don't worry about it.

[gator1]

@Horton‌ my vote : leave it alone. Go change a diaper.