Those who went through the 9 exercises in TRANSITIONING THE SR STANCE TO THE SKI BOOT probably ended up with a number of red flags. Starting with this post, I will go through what I consider to be the essentials of boot-fitting.
While I use the term boot-fitting, I prefer the term boot-modification. Boot-fitting and fit of a ski boot imply a fit of the boot with the foot and leg that results in a degree of dysfunction of the foot. The key to skiing with minimal effort and maximum balance and comfort is a ski boot that creates a functional environment for the foot and leg as opposed to a ski boot that creates an environment that results in a significant degree of dysfunction of the foot and the entire lower limb.
Achieving a functional environment in a ski boot for the foot and leg is about sequence. The fastest route to a ski boot that provides the best functional environment for the foot and leg is a step-by-step process; one that assesses the effect of each essential component in a systematic manner. A minimalist approach makes it easy to assess the effect of changes such as substituting a custom footbed that supports the arch for a baseline flat insole. The gold standard in studies to assess the effect of interventions such as insoles and orthotics is to compare barefoot balance on one limb to balance on the same limb in a specific form of footwear to balance on the same limb in the same form of footwear fit with an insole or orthotic. This protocol enables the effect of a compounding series of interventions to be assessed against a consistent baseline; in this case, barefoot balance on one limb.
Where I Start
At the bottom. By at the bottom, I mean the boot board (aka, the Zeppa).
I prefer to start with a monoplanar boot board. Monoplanar means flat in both the long and transverse axes of the boot board with the plane of the transverse axis parallel to the base plane of the sole of the boot.
Why monoplanar? Because the shape of the boot board can significantly affect foot function and the fact that the shapes of boot boards and materials and construction can and do vary considerably from one boot brand to another and sometimes even among different models in the same brand. The shape of a boot board can also act to compound the shape of custom footbeds and orthotics. A monoplanar boot board establishes a baseline with which to assess the effects of foot function irrespective of the boot brand or model. A monoplanar boot board and a flat insole serve as a baseline reference with which to assess the effect of any changes to that alter the monoplanar surface form of the boot board.
In my opinion, boot boards are one of the weakest components of a ski boot. Boot boards are one of the first things I check when I am considering purchasing or working on new ski boot. In future post, I will discuss a recent study that raised significant issues with boot boards.
What I Look For
Ramp or Zeppa angle is important. But before I even consider this aspect, I check the construction and materials of the boot board. Although I have not conducted an extensive review of boot boards, I consider both the boot boards and the insoles (after heating and pressing them flat) in Head Raptors some of the best I have seen to date.
The photo below shows a boot board from an Atomic boot (upper 2 photos). A boot board from a Head Raptor is shown in the bottom photo.
The 2 photos below are of side and top views of a boot board from a Head Raptor SD. One thing I deem important is continuity across the heads of the metatarsals, especially the head of the first metatarsal (ball of the foot). With the boot board in place, no break in surface continuity should exist between the interface of the boot board and the surface of the boot shell. It is especially important that there is no step at the interface where in the boot board or shell base are at different elevations.
The photo below shows a boot board from a Salomon SX 90 rear entry boot. This type of boot board construction is still found in some recreation boots. I would not consider a ski boot with this type of boot board.
The main reason I prefer boot boards like the one shown in the photo below is that it is fabricated from dense hard foam. Any contour can be quickly and easily removed with a sharp block hand plane. Ramp angle can also be easily and quickly adjusted with a sharp block plane. I use a belt sander to finish the surface
When the front portion of a board needs to be raised to correct zeppa angle, I use a material like dense gasket cork. The photo below shows boot board from a Head recreational boot with a layer of cork added to the front half to reduce ramp angle.
With the boot board in place in the shells, the insoles from the liners should be placed on top of the boot boards in order to ensure that the foot is sitting at the correct elevation in relation to the shell walls when checking for clearances. The insoles shown in the photo below are from a Head Raptor.
In terms of resiliency and surface texture, the Head insoles in the above photo are some of the best insoles I have found to date. I heat and press them flat in order to create a baseline insole.
Once a skier or racer has adapted to the baseline fit of a ski boot they can replace a baseline insole in one boot with a custom insole or orthotic and compare it to the baseline insole in the other boot. If the boot is perceived to be better with the custom insole or orthotic, the baseline insole in the other boot can be swapped. If there is any doubt after a ski-in period, the process is easily reversed.
The protocol I follow is to make one change at a time and always ensure is quickly and easily reversible.
My next post will be on BOOT-FITTING 101: THE ESSENTIALS – FOOT TO SHELL CLEARANCES