Biostance Products


Background
To maximize skiing enjoyment, proficiency, and safety, all skiers should have their equipment anatomically adjusted. One of the most critical anatomical adjustments is referred to as "canting".

Canting alters the lateral tilt or "cant angle" at which a boot supports a skier's foot and lower leg, relative to the longitudinal running surface or bottom plane of an attached ski. Optimizing the cant angle improves skeletal alignment and allows the skier to tilt or "edge" the ski with the least amount of muscular effort.

In the 1993 book "The Athletic Skier", authors Warren Witherell and David Evrard wrote that, "Only when properly canted can our bodies and skis work as efficiently as possible. By tilting or canting our boots, we can precisely control the geometry of our legs and establish an ideal position over our skis. Canting is the final step in the alignment process that makes efficient and balanced skiing possible for all skiers."

Unfortunately, as was the case back in 1993, most ski shops still do not offer canting services. Experts would agree that only a small percentage of all skiers have ever had their cant angle tested or altered. There are numerous reasons for this which will become apparent in the review of prior art.

History
Various techniques exist for altering the global cant angle at which a boot supports a skier's foot and lower leg, relative to the longitudinal running surface or bottom plane of an attached ski.

The classic method is to mount wedge-shaped shims or "cants" between the top surface of the ski and the under surface of both the toe and heel units of the ski binding. Some skiers have used strips of tape on both the toe and heel as temporary or test cants, as depicted in "The Athletic Skier", Chapter 34.

Another well-known method for altering the cant angle is to grind or plane the bottom external sole of the boot so that the entire boot structure becomes permanently tilted or canted from its original angular orientation.

A reversible variation of this technique is to use interchangeable "canted soles" as described in U.S. Patents No. 4,078,322 and 4,945,659.

Another approach is to utilize a ski boot with an adjustable sole that can pivot along a longitudinal axis as depicted in U.S. Patent No. 5,615,901.

Each of the above listed approaches has many problems.

While the method of using wedge-shaped shims or "cants" can be effective for altering a skier's cant angle, it often requires a time intensive process of custom mounting or remounting the binding on each pair of the customer's skis. First, a technician must cut and drill the appropriate cant shim material to match the shape and screw hole pattern of the particular binding being used. Next, the technician must carefully choose longer length screws to install the binding with the cants to meet International Standard ISO 8364 for screw depth and binding retention forces. If the screws chosen are a little too long, an expensive ski can easily be ruined. If screws are too short, the binding can pull out leading to potential skier injury. Because screw head shapes are often specific to particular binding brands and models, screws must be stocked in a multitude of styles and various lengths.

The above procedure also creates a specific left and right ski due to the angular orientation of the cant shims installed. This prevents a skier from reversing his left and right skis out on the hill which is desirable as edges become dull or damaged, especially for performance minded skiers like instructors, patrollers and racers.

An ever increasing number of skiers want to rent skis versus own, or at least "demo" various models before they buy. Due to the time requirement and cost of installing cant shims, canted rentals are simply not offered. Yet proper canting can make the difference between a great skiing experience and never wanting to ski again.

There is also a growing retail trend towards selling more integrated ski-binding systems that first arrived on the market about six years ago. On many of these systems, the binding is not attached to the ski with screws, but by various other means such as sliding the binding onto rails or tracks integrated into the ski construction. In these cases, the classic method of installing cant shims is not possible.

Due to the above problems and limitations on installing cant shims, a small percentage of ski shops have chosen to offer ski boot "sole planing" services, in particular, at mountain area locations. Many ski instructors, patrollers and racers in these areas own multiple pairs of skis and believe in the practice of altering the cant angle of their boots via sole planing versus having to install cants on each pair of skis. They also like to sometimes swap their left and right skis out on the slopes as edges become dull or damaged. They believe their boots have been planed accurately by their local boot fitting guru and that their skis and bindings are predictably flat from the manufacturers.

Unfortunately, grinding or planning the bottom external sole of a boot is often an imprecise operation that requires the use of dangerous machinery by ski shop employees. Because it's irreversible, a slight mistake can ruin an expensive pair of boots. It also requires that the boot toe and heel portions be built back up to meet International Standard ISO 5355 for boot sole thickness and shape dimensions.

The use of interchangeable canted soles requires that a special boot be purchased and that the ski shop stock additional components only useful for the particular boot that supports the feature. Due to the cost of producing interchangeable canted soles, they have only been available in gross cant angle increments of 1 degree or greater.

The production and use of the ski boot design in U.S. Patent No. 5,615,901 with a pivoting adjustable sole has not proven to be practical because of mechanical problems of implementation and the added weight and cost to produce the boot. This patented product is no longer on the market.

Accordingly, a need exists for a simple canting solution that does not require skilled or highly trained technicians and that provides a fast, accurate, safe, inexpensive and widely available means for adjusting and optimizing a skier's cant angle.