THE PURPOSE OF THE SKI BOOT


As a prelude to discussing the objectives of my work with Whistler-Blackcomb Ski Pro, Matt, it is important to establish the position of various authorities on the purpose of the ski boot from the perspective of skier function.

Here is what the authorities cited below said in 1987

From a technical (skiing) point of view, the ski boot must represent an interface between the human body and the ski. This implies first of all an exchange of steering function, i.e., the skier must be able to steer as well as possible, but must also have a direct (neural) feedback from the ski and from the ground (snow). In this way, the skier can adapt to the requirements of the skiing surface and snow conditions. These conditions can be met if the height, stiffness, angle  and functions (rotational axes, ankle joint (AJ)/shaft) of the shaft are adapted, as well as possible  to the individual skier.

The modern ski boot must be designed from a functional point of view, i.e., the design must take into consideration the realities of functional anatomy (axes etc.). It (the design) should not make compromises at the expense of other joints (length of shaft, flexibility and positioning). It (the ski boot) must represent the ideal connecting link between man and ski (steering and feedback).

Biomechanical Considerations of the Ski Boot (Alpine) Dr. E. Stussi,  Member of GOTS –

Chief of Biomechanical Laboratory ETH, Zurich, Switzerland – 1987

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The ski boot and it’s shaft must be adapted to the technical skill of the skier, and the technical skills of the skier must be adapted to the preexisting biomechanical functions of the leg and the foot. The medical requirements with respect to sports should not be construed as criticism of the boot industry. It is hoped that they are contribution to the development of a ski boot designed along anatomical principles. This goal has not yet been achieved.

Kinematics of the Foot in the Ski Boot – Professor  Dr. M. Pfeiffer – Institute for the Athletic Science, University of Salzburg, Salzburg, Austria

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The lack of proper technique seem so often is not due to a lack of ability, but to an unsatisfactory functional configuration of the shaft in so may ski boots. This is particularly true in models designed for children, adolescent and women. In the future, ski boots will be designed rationally and according to the increasing requirements of the ski performance target groups.

Ski-Specific Injuries and Overload Problems – Orthopedic Design of the Ski Boot –  Dr. med. H.W. Bar, Orthopedics-Sportsmedicine, member of GOTS, Murnau, West Germany

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Here is what I said in 1992

The interaction between the foot and the footwear necessary to elicit optimum response from the medium to which it is attached is not well understood. Skis, ice skate blades, roller skate wheels and the like represent a medium designed to produce specific performance characteristics when interacting with an appropriate surface. The performance of such mediums is largely dependent on the ability of the user to accurately and consistently apply forces to them as required to produce the desired effect. 

In addition, in situations where the user must interact with external forces, for example gravity, the footwear must restrain movements of the user’s foot and leg in a manner which maintains the biomechanical references with the medium with which it is interacting.

It is proposed that in such circumstances, the footwear must serve as both an adaptive and a linking device in connecting the biomechanics of the user to a specific medium, such as a ski, for example. This connective function is in addition to any type of fixation employed, in this instance, to secure the footwear to the ski. 
Alpine ski boots, ice skate footwear and cycling shoes are among the many types of sports footwear known. As with all sports footwear, the objectives in design and construction are to facilitate and enhance performance in the particular sport and to provide comfort to the wearer.

US Patent No 5,265, 350 February 1992 – MacPhail, David Michael

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After the skier, the most important piece of equipment in the skier/ski equipment system is the ski boot. The conventional ski boot has the biggest influence on who rises to the top technically. Those who are able to connect with the snow through their feet so as to enable the use of their natural  mechanisms of balance are unlikely to lose the resulting kinaesthetic association. When these skiers try on a new boot, they usually know within seconds whether it will work for them or not without even having to go on snow. But for nine out of ten never-evers, the initial skiing experience involves such a severe disconnect from familiar sensations, especially a compromise of balance, that is so unsettling that their first day on skis is also their last day.

It is for this very reason that the consensus of the previously cited authorities is that a ski boot should be adapted to the functional requirements of the user and not the other way around. It is particularly important that the ski boot not incur functional compromises on the part of the user. A properly designed ski boot should enable the user to utilize mechanisms of ski control that are complimentary to and consistent with, their innate mechanisms of balance.

In my next post, I will  use video clips and annotated screen shots to describe how Matt’s ski boots were compromising his function and the process by which his boots were modified so as to adapt them to Matt’s functional functional requirements.