ankle dorsiflexion impairment and skiing performance

jzamp,

"So here's the question: how much does the degree of dorsiflexion influence performance "

The answer: A whole bunch!

First: How much forward lean does your set of boots have?  What is the boot board angle, (heel to toe differential) of your boots?

Next:    Place a carpenters square, upright behind the heel of your boots and measure to the liner at top of the shell. Now, simulate the boot board angle first then, stack books up under the heels of your feet,(this will tilt your knee forward) until your calf is far enough forward (at boot top elevation), (equal to the forward lean measurement of the boots) this will allow you to stand in your boots without your left heel being pulled up.  This measurement is how much heel lift you would need inside both your boots to try to even out your turns somewhat (get them symmetrical).  Question is-----Is there enough instep height in your boots to allow this much heel height adjustment?  

By the way: You need stiff boots, not soft. 

and-----"You need a boot fitter".

mike

Jzamp,

I ski that same boot and love it!

Agree with Miketsc above.  You should also remove any spoiler shim behind your calves.  This will also help to open the ankle joint which is the goal with limited dorsi flexion.  If your boot board, with the steeper ramp angle, needs a bit more angle, it can be easily sanded with a belt sander to increase the angle more without tightening up the instep area.  If doing this you may need to add a bit of padding above the toes and forefoot area to eliminate excess play?

The last parameter to consider in your fore/aft balance scenario is the binding delta angle which is created by the "stand height differential" or the difference in height from the toe piece and the heel piece which creates an angle under your boot soles.  Changing this by as little as a couple millimeters can make a very noticeable improvement in your fore/aft balance and stance.  But address the dorsiflexion issues first before experimenting with delta!

good luck!

your quote,-------"i can change the ramp angle by changing the inserts."

The specs on your boots bootboards should be available through your local dealer,

although I dint think the angle much matters if you are going to try to move your knee forward by lifting your heels,

just lift them till you can stand in the boot without your heel pulling up.

mike

Jzamp,

Yes, boot board and ramp angle are pretty synonymous.  Your actual ramp angle is the sum of the angle created by your boot board (or zeppa) and your footbed (ie: the thickness under your met heads in relation to the thickness under your heels).  

I measure boot board angles with a digital level placed inside the boot on a flat surface.

removing the spoiler(s) will open the ankle more and stand you up taller.  This should not cause any slop as the power strap and buckles will close the gap.  Consequently, making these adjustments to the ramp and forward lean may necessitate increasing your delta angle a couple millimeters to get your knees to plumb over your toes more (a good static starting point).

Here's a pointer you should also try.  Before latching the top two buckles on your cuff , wrap your power strap around just the liner and tongue pulling your leg back against the boot spine, then wrap the upper cuff plastic over the top of the power strap and buckle as normal.  You will notice a more positive energy transmission from shovel to tail without any gapping or lag time.