Bootfitting Discussion from the thread: MA and what to focus on next.

[Mike King]

Again, the key word is universal. I doubt Josh or I ski in the back seat. I very much doubt if you watched either of us ski that you'd think,"gosh, they have heel lifts''. I've seen improperly set up boots with my own eyes as well... both with and without heel lifts. I've found no universals. My question... Do you imagine a WC athlete's lower leg is similar to most people walking into a shop? Do you think Steve Nyman's boot set up resembles Bode's? Or Mikaela's looks like LV's? What I think Jim might say is "heel lifts are often used too indiscriminately", and I'd agree, but I don't know Jim, so I can't really venture to guess. You and I, we'll just have to agree to disagree. All I know is that any time I find myself thinking in absolutes, I need to revisit my assumptions that lead me to a particular conclusion.

If you look at what I said:

Try the experiment I suggested and you will see that the result is to move the person aft: as the heel of the boot is lifted, the tibia is moved forward and to remain in balance, the knee must flex, resulting in the hip moving aft. There might be reasons to do so (such as limitations in the ability to dorsiflex), but such adjustments should be made based on anatomy, not based on the skier's predilection to ski fore/aft unless that's a limitation of their anatomy.

You will see that the result is as follows. 1. A heel lift UNDER the boot will 2. Pitch the leg shaft forward, which 3. Must result in moving the knee forward. In order for the skier to remain in balance, either 4a the knee must flex, resulting in the hip moving aft or 4b the hip must open, resulting in the body moving aft. That’s the biomechanics, and it is universal.

That doesn’t mean that the relationship of the CoM and the BoS has changed! The person’s CoM is still in the same relationship to the BoS, UNLESS the balance point under the foot has changed (e.g. the person is hanging off of their equipment — which is limited by the length of the platform under the foot — either the sole of the boot (pretty short, but still possible to hang off of, or the ski, quite a bit longer). If the isssue in the skier’s skiing is hanging off of the equipment, then the solution is to solve their mechanics UNLESS there is a range of motion issue that is limiting their ability to do so (e.g. insufficient dorsiflexion or plantar flexion).

In other words, trying to solve a mechanics issue through the boot is the wrong path UNLESS there is a bio mechanical limitation that requires an adjustment of the boot to solve a situation where the RoM puts the skier into a process of hanging on the equipment.

I didn’t imply that you, Josh, or anyone else is skiing from the back seat. Rather, using gas pedals or heel lifts addresses ankle range of motion limitations, but it won’t, most likely, solve fundamental stance issues the are NOT attributable to physiological limitations.

BTW, did you look at the MacPhail pages I included a link to above? If so, what’s your opinion on those? Particularly his observation that more than about 3 degrees of net ramp angle leads to fundamental stance limitations?

 

[T-Square]

This thread is to discuss the Bootfitting aspects of the original thread.

 

[Jamt]

IMO lifting the heel doesn't change balance very much, unless the change is major. Otherwise athletes in all sports would fiddle a lot with this.
Changing the forward angle of the cuff changes a lot though, and off course if you lift the heel under the boot or binding you also change the angle of the cuff.

The simplest way to modify a sucky childs boot like the OP's, without buying a new one, is to insert a wedge in the back of the shaft.

Ask the child to stand in the boot shell in an athletic balanced position. "be ready to receive a basket ball pass". That should give you an idea how thick the wedge should be.

Oh, and regarding the discussion between @razie and @Mike King , I'm pretty sure Mike responded to the wrong post, Razie's instead of Josh's.

 

[Bolder]

While the experts argue about shims, dorsiflexion and tib/fib ratio, I would suggest (as I mentioned earlier in the thread) that the girl start with a well fitted pair of 4-buckle boots, done up the correct way. Kids are not at all sensitive to things like shims etc, but they will learn technique quite well. My kids have been able to advance their skiing by leaps and bounds just with regular lessons (and progressively better gear, so long as I am the one verifying correct boot tigthening!)

 

[L&AirC]

I'll throw in my two cents.

One of the first things I do with my athletes is go through their boots with them. How to take them apart, the different pieces, and buckle correctly. While they are all apart, I have them stand on the insole in their socks and take a picture. The foot should fill the insole. For those that don't I take the picture with a ruler showing that some of them are in boots 1.5" too long! Some of the boots are three buckle and most are 4 buckle. It's mostly a size things as I coach U10s.

Once back in the boots buckled properly, I have them flex (not in skis) and watch for knee movement. If it isn't moving, they can't flex (we are inside). I make sure they are flexing and not just leaning forward. I gather up the data and present it to each parent with my recommendations.

My recommendation to the OP is to start there. Whether it is a good boot or a bad boot doesn't matter much if it is a poor fitting or too stiff boot.

Ken

 

[DavidSkis]

This is crazy - Tom Gellie just posted on this very topic on Facebook. I think I'm linking to it here. The gist is that he finds ramp angle interferes with engaging some of his lower muscles. He closes by identifying that there's not good scientific evidence in favor of ramp angle.

I have no iron in the fire on this one - just find it interesting.

 

[François Pugh]

Shims lifts etc..... It's too soon to start worrying about those details. Take her in to boot fitter who fits lots of kids on race teams and let him worry about getting the fit and setup right with the descent boots he picks for her.
At least get her some decent boots and stop making her ski without the boots done up right.

 

[Uncle-A]

Is this more about fitting or about helping this 9 year old female ski better? Some said buy her a four buckle boot, why not take her to a professional ski shop and get her a season rental that is a four buckle boot. Get the shop to do a good fitting job not just throw boots at her as many shops do. As a season rental vs a purchase you can get a closer fit and not have to worry about out growing the boot just turn it in as the foot grows. The Lange that was suggested above may be a good selection when my daughter was small she had good luck with the Lange boot and now as an adult the last time we skied together she rented a Head ski boot with good result.