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Adjustments for knee and ankle injuries

post #1 of 10
Thread Starter 

I have complicated feet. I am reasonably happy with my highly customized 

boots but I have what seem to be extreme settings in order to be able to 

carve nice turns. It is a very fine tune to be able to carve and I have some bad days. I ski 4 times a week. 

1) does it makes any sense that the boot settings below should work? 
2) is there something off that required extreme compensation in other 

parameters?
3) should I have a firmer fit of my boot on the arch to compensate for weak ankles, or looser fit to allow more degrees of pronation and supination for edging for my reconstructed knees?

Numbers:

forward lean: 22 degrees (5 of that from shimming the cuff)
boot sole ramp: 3 deg from external shim. Helps noticeably with carving
Heel ramp in boot: unknown, probably incresed 5-8 degrees over stock, i edge better and have less ankle pain with increased heel ramp.
Tibial inclation from vertical when skiing: about 30 degrees net. There is little movement of my tibia before I pressure the tongue.

Skis:
Dynastar Legend stock mounting position. 

What it feels like skiing: I'm skiing these skis pretty well now. I mostly ski on somewhat steep, often icey bumps, horrible before heel ramp and forward lean were increased. Railroad turns on easy slow are almost there, but still a challenge - ankles hurt to evert. On carving skis I feel a little too far forward even without the external shim. 

 

For reference:

My anatomy - 52 yoa, fit
Bilateral ACL grafts in knees somewhat limit rotation. 
Many ankle sprains in all directions in soccer (hundreds), very lax 

ligaments with no firm "stops"
severe flat feet and limited eversion with feet flat on the ground
right ankle benign tumor - fat and about 3 com round attatched to the 

tibia just above the medial malleolus - painful with pressure and with 

eversion or forced, but not passive ankle plantar flexion
severe hallux vagus bunion on right


Boots 

Shell: 
Dalbello Krypton Cross with replaced stiffer external tongue, which is 

heat moulded to more forward lean and to relieve pressure on top of the 

ankle joint.  Also heat moulded to relieve bunion pressure.
stiffness insert set for maximum stiffness. 


Footbed: 
arch and heel both substantially raised, custom moulded by a good 

bootfitter, comfortable, Heel lifted about 8 mm.

Liner:
replacement (?zipfit) liner fits like a glove and took care of all 

pressure points

cuff :
no cant,  10mm shim for forward lean. Booster strap added to pull tongue closer to the tibia 

exterior:
5mm lift under boot heel. 
ski platform is flat. 

 

Thanks!!

post #2 of 10

without seeing you, I would have no idea, can't imagine anyone else  would either.

 

where did you have the work done?

 

mike

post #3 of 10
Thread Starter 

:( I guess that's fair. I was hoping to get some comment on the numbers since I did most of that myself. Lionel Hering at Happy Tunes in Carrabasset Valley, ME did the liner and footbed. The footboard and some of the shell molding was done by Rob at Snow and Ski in Ann Arbor. I did the rest, which is why I'm second guessing so much. So If I could rephrase as general questions:

 

1) what is a reasonable range for tibial angle to the vertical while in a functional ski stance, as opposed to boot forward lean?  It seems the numbers could differ by 10 to 20 degrees depending on the boot.  

2) Is a boot liner and buckle setting that strictly limits foot inversion/eversion a good or bad thing for effective edge setting?  

3) how much does optimizing ankle ramp angle affect tibial rotation range and edging, as opposed to movement in the frontal plane? 

post #4 of 10

Are you racing or recreationally skiing?

 

if recreationally skiing it is more of an advantage to have your COM centered over the boot sole center when your femur/thigh is almost perpendicular to the ski running surface.

 

The amount of forward lean will be dictated by the circumference of you calf at the top of the boot liner. A larger calf will need less forward lean in the boot shell than a smaller one.

 

We use a laser to get a fix on where you are standing,  then modify the boot to allow the skier to stand in this centered up position.  

 

mike

post #5 of 10
Thread Starter 

Super helpful! Thanks.

 

I have small calves. I am an aggressive recreational skier. The COM thing gives me a great starting point to thinking about my stance.  I prefer not to stand so tall on the skis because i ski a lot of cruddy, irregular snow, nor do i like to bend over at the waist as much as the racers will. And I like my boots very stiff. Perhaps this explains why i like so much forward lean in the boots. That plus skiing Eastern Ice on skis designed for softer Western conditions. 

 

Still unclear on the question about degree of foot articulation allowed vs. optimal carving. Maybe depends on technique?

post #6 of 10
Quote:
Originally Posted by SlowSteady View Post
 

Super helpful! Thanks.

 

I have small calves. I am an aggressive recreational skier. The COM thing gives me a great starting point to thinking about my stance.  I prefer not to stand so tall on the skis because i ski a lot of cruddy, irregular snow, nor do i like to bend over at the waist as much as the racers will. And I like my boots very stiff. Perhaps this explains why i like so much forward lean in the boots. That plus skiing Eastern Ice on skis designed for softer Western conditions. 

 

Still unclear on the question about degree of foot articulation allowed vs. optimal carving. Maybe depends on technique?

I highlighted the pertinent parts of your post.

 

So----what size calves do you have? measure circumference at top of liner.

what size boots do you have?

do you have a problem with releasing your uphill ski at transition? do you have to pick it up?

 

mike

post #7 of 10
Thread Starter 

I really appreciate the dialog. 

 

calves are about 26 or 27 CM around at top of liner. 

 

I remembered where the pain comes incorrectly, it comes rolling onto my little toe, hurts in the opposite medial side, when i tighten those tendons to execute the inversion. 

 

Just off the slopes, typical day. started out with pain every time I tried to roll my ankle to start the ski on edge. yes trouble releasing, but more the downhill, soon to be inside ski due to inversion issue.  I wouldn't stem or air stem, but I wasn't turning as tight as I want or with accuracy, using too much hip lean and not initiating with lower leg.  I started with buckles on firm.  It was initiating the turn to the right with my inside right ski. On steeps it was better, good fore/aft balance,  but i was going fast and not doing tight turns.  Testing my own question, after the initial runs I unlatched the bottom two of 3 buckles completely.  The pain decreased as i could roll my ankle with less effort, I got more edge, and carved some nice symmetric tracks, then did the steep bumps with good form and speed control. My ankle still hurt a little, and i have a little wobble evident in my tight turns on groomed. My skis are too close together, bad habit from stabilizing injured joints now and in the past, but i think only an instructor would notice. 

 

So I've got an itch to experiment again, using an extra footboard I acquired  to grind the outside and inside and make an arched platform for the footbed that will aid in rolling the foot more freely from edge to edge before engaging the boot. Curious what you think. 

post #8 of 10

I think a foot rolling around inside the boot is not good----don't grind the bottom of a foot bed to create roll---your foot needs to be at or near sub talor neutral.

 

A human foot had a thick fat pad on the underside to provide shock absorption---this fat pad will allow the bones in your foot to move around quite a bit (enough) with out adding rolling motion on the underside of a foot bed.

 

be more accurate about your calf size please---there is a 10mm difference between a 26 and 27cm size---a change of 2mm in forward lean can affect COM adversely

 

what size boots?

 

It sounds like you may be over tightening the lower shell and pinching a nerve in your foot---only tighten the ankle and upper shell on the boot you now have.

 

A 4 buckle boot works better, in that the ankle buckle (pulls back on the ankle) it does not pull downward on the top of the foot like the 2nd buckle does on your boots this pulling down on the foot will pinch a nerve on top of the foot.  If you boot fits around you feet you should not need to tighten the lower shell to hold you foot still.

 

every instructor will tell you to "stand tall" on your skis so that you have the ability to absorb the terrain---skiing in a too flexed position uses up some of your ability to absorb---you might need to rethink this idea, plus all of us run into crud at times out on the hill so, why should you be different:).

 

mike

post #9 of 10
Thread Starter 
Quote:
Originally Posted by miketsc View Post

-this fat pad will allow the bones in your foot to move around quite a bit (enough) 

---Makes sense, especially with buckles looser.

 

-a change of 2mm in forward lean can affect COM adversely

---Wow that is sensitive. I'm calculating that as about 1 degree. Very good to know. 26.4mm 

 

what size boots?

--310mm boot sole, size 9 US. 

 

over tightening the lower shell and pinching a nerve in your foot-

---Very astute, I think you are spot on. I fit the boots with thin ski socks, but was sometimes using street socks, then tightening to compensate. I tried ski socks again and it was fine

 

every instructor will tell you to "stand tall" on your skis so that you have the ability to absorb the terrain---skiing in a too flexed position uses up some of your ability to absorb---you might need to rethink this idea, plus all of us run into crud at times out on the hill so,

--- I taught my kids this way, I skied this way with soft recreational boots for 30 years.  Now with my boots about as stiff as racing boots it doesn't work to bend knees to absorb shock because it throws me back. I set my boots so i can comfortably stay centered while standing with slight knee bend and also stay centered while  touching my toes with femur parallel to the ground. 

 

why should you be different:).

Not because I'm older, stiffer, have multiple injuries and operations, but because I choose a certain style skiing and expect my equipment to make that as easy as possible.  

 

Show me a racer in a fully upright position except when reaching for the ground while airborne.  I want the most range of motion while staying centered on my skis, and I want it with stiff boots because I like the precision and quickness of response.  That's how I arrived at the numbers, and you have helped a lot in giving me confidence that the numbers are that way for a definite logical reason, even if it isn't the norm.  That's all i wanted, and i thank you for everything. 

 

mike

post #10 of 10
Thread Starter 

I hope it's okay to add this so I don't mislead anyone who happens on this thread some day:

 

after a busy ski season my boots are working okay,  but i found variation in temperature, the ski type and binding mount could easily throw me off. 

 

1) Its been very cold and the boots have been like concrete, which is when they worked best. . when it is warmer the forward lean is a bit much and they are too easy to compress.

 

2) When I changed back to my old park/all mountain skis (2008 Sal Dumonts) mounted in "all mountain" position they were almost unskiable with that much forward lean. I was levering the back of the cuff to get a edge.  I suspect that i will find the same on my new skis if I encounter fresh snow in CO, which is what they are made for.  I plan to remove most of the forward wedging  of the cuff on my trip.  I was really surprised how much the comfortable forward lean setting or me depended on the type of ski and conditions. 

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