Boot Alignment

BOOT ALIGNMENT

and the SECRETS OF GREAT SKI RACERS

 

 

All athletes who are investing significant amounts of time training and racing, and are stiving to be the fastest that they can be, should be aligned properly in their ski boots. This usually involves custom footbeds, fore-aft adjustment, cuff alignment and boot sole canting. Many of you have worked with Don Waldein the past to get this type of work done. Make an appointment with Don to take care of boot fitting and fine tuning to best be prepared for a stellar 2007-08!Beware: Not all ski shops and bootfitters complete this full process. And, some try to correct alignment issues with improper techniques. Make sure you are seeing the best, if you wish to ski your best!

Do so as early as possible to make sure that Don can fit you into his busy schedules. The entire alignment process can take 2 hours or more, so be prepared to allocate that amount of time to this process.

Boot Alignment

Complete boot alignment consists of at least 4 steps:

1. Creation of a custom orthotic (footbed)

2. Fore-aft analysis/adjustments

3. Lateral cuff adjustment

4. Undersole boot canting

1. Custom footbeds

First, a custom footbed should be created. A footbed should be heat-molded to the bottom of your foot. This creates a personal impression and support for your body. Then, the underside of the footbed is "posted" with material to fill in the high spots under the foot. When a custom footbed is properly designed, upon weighting of the feet, the feet do not become distorted and the bones stay better aligned.

For instance, in a skier who experiences eversion (pronation, in layman terms), the arch collapses under weight, the forefoot "splays", the ankles bones come out of alignment and the tibia internally rotates. This is easy to see with a trained...or an untrained eye. This can be seen from almost any angle. However, if viewed from the back, you may also notice that the achille's tendon tips inside as the tibia rotates inward.

This particular example results in is a skeletally weaker position. Furthermore, the skier's ability to manipulate the edges of the skis changes. With someone who experiences eversion, that they will be on the inside edges and unable to extend the feet away fromt the body. In effect, maximum edge angle will develop while the feet are in close proximity to the hips (makes full ROM flexion/extension impossible). Furthermore, when straight running, someone who is out of alignment in this fashion will have difficulty riding a flat ski. Tell-tale signs are feeling overly-"edgy" and appearing to have an "a-frame" stance instead of one that ideally approaches parallel, when relaxed.

Latest trends:

Bootfitters on the "cutting edge" are moving away from footbeds that eliminate all movement. While eliminating most arch collapse and foot distortion, footbeds should not eliminate all movement. Balance is refined by co-contraction of the foot muscles. Try this: take off your socks and shoes. Next, balance on one foot. Notice what your foot does while you balance on it. Those micro-adjustments are the foot muscles co-contracting. And, the "right" footbeds do not eliminate the foot's ability to balance.

For instance, Superfeet footbeds (the cork ones that use non-weighted vacuum-impression technology) are widely considered as being too restrictive. Also footbeds that are posted with too much material or material that is too rigid, are not ideal.

Both Don and Eli make footbeds that support the foot, while allowing for necessary balancing movements.

2. Fore-aft adjustments

Second, a bootfit alignment expert should check your fore-aft balance in the boot. There are several things that can be done, some outside of the boot, and some inside of the boot, to influence this. And, as Eli Koski notes, "many lateral alignment problems can be eliminated if fore-aft issues are first addressed."

For instance, if a boot holds you "in the back seat", a bootfitter can lift the toe or heel and change your center of balance. And, for those with limited dorsiflexion (ankle flexion), fore-aft considerations are paramount.

3. Lateral cuff-adjustment

With the liner out of the boot, the custom footbed should be placed inside the shell. With the skier inside, the bootfitter can inspect how the lower leg aligns with the lateral angles of the cuffs. If the leg crowds the inside or outside of the cuff, the cuff can be rotated in or out. The result should be a cuff alignment that leaves the lower leg shaft in the CENTER of the shell's cuff.

Beware: "Corrective" adjustments with the cuff are not acceptable. The cuff should conform with the leg. The leg should not be influenced, laterally, by the cuff.

4. Undersole boot canting

Once the above steps have been completed, it is time to put the skier back into the boots, with the footbeds inside the liners, for undersole canting analysis. Bootfitters use a stance balancer or a plumb-bob for this process.

The goal is to find the center of the knee mass, and determine how his point aligns over the foot. For example, look at the above diagram. This skier is "overedged" or aligned "to the outside". In layman terms he might be supinated. The tell-tale sign is if a skier appears to be a bit "bow-legged". Probably 20-30 pecent of people find themselves in this category.

The opposite is found in pronated (those with eversion) skiers. Their lower legs anlign inward and form a shape like the letter "A". Something like 70 percent of folks are in this category. Chuck has significant eversion...on the order of 3% per leg.

Ideal lateral alignment leaves the center of balance (where the plumb-bob would fall) somewhere between the midline of the boot shell mold and the medial side of the second metatarsal.

The undersole canting process can be achieved by two methods:

Cant shims: These are installed in between the bindings and the skis. These change the angle that the skier finds himself on the skis. So, for someone that is everted, or pronated, the thick side of the shims are intalled on the inside of the skis. Basically, the goal is to move the knee outside (laterally), to neutral. For someone that is supinated (inverted) the thick sides of the shims are installed to the outside, thus bringing the knee inside (medially), to neutral.

Cant shims are ideal for younger athletes and those who have only 1-2 pairs of skis. Remember, once you have shims mounted on your skis, you will have distinct inside, and outside edges

Sole grinding: Sole grinding is reserved for older athletes; especially those who have multiple pairs of skis. Material is planed from the sole of the boot to achieve the desired angle. So, for someone who is everted, material is planed from the outside of the boot sole. The converse is performed for thos who are inverted.

Of course, grinding a boot results in a boot that no longer conforms to din standards and will no longer interface with a binding correctly. So, the bootfitter installs riser plates on the boot soles to build the sole back up, and actually PAST din thickness. The final step is performed by using a router to take material off the top of the toe and heel, at the angle previously created on the sole, and to the precise thickness required for the boot to meet din requirements.

Once the skier is properly canted in the boots, you have completed the alignment process.

** The best bootfitters realize that boot alignment is not an exact science. Specifically, it is a dynamic process, specific to each skier, that should also include on-hill observations, by coaches. So, prior to getting boot soles ground, or cant shims installed, it is highly recomended that skiers spend a weekend skiing with their new footbeds, cuffs aligned and fore-aft adjustments.

For more information talk to Chuck.

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