Alpine Skiing for Disabled People

The natural evolutionary consequence of a contemporary sport is the organisation of its whole structure (rules, categories, federations), culminating in different competitions. The development of new techniques and equipment made the participation of special needs athletes possible in Alpine Ski competitions (Slalom, Giant Slalom, Super Giant Slalom and Downhill). Nowadays, Alpine Skiing is divided into standing, sitting and visually impaired classes (Table 8), which keeps the same criteria used in Nordic Skiing (IPC).

Table 9: Alpine Skiing basic functional classification, not complete (http://www.skiteam-alpin.de).

Skiers Functional

Disabilities of the lower limbs with a regular to good sitting balance Mono-skier (low incomplete Spinal Cord Injury)

6.2.1 Historical development of the Monoski

The development of Alpine Skiing began in the last century, as shown by Matthias Zdarsky in his book “Alpine Lilienfelder Skifahr-Technik” in 1896, in which he presents techniques and equipment from the beginning of the sport (Barth and Brühl, 2005). However, the development of AS and adapted skis for people with special needs are part of a more recent reality, beginning in the 1950's when amputee veterans of World War II began skiing as an experimental and leisure form. The West Germans are credited with the invention of skis attached to rods that were used to help maintain balance. At that time, during the Winter Games, there was the first participation of disabled people in organised competitions.

At the end of the 1950s and beginning of the 1960s, skiing for amputees was the mainstay of the handicapped sport. It was at the end of the 1960s and beginning of the 1970s that other people with differing forms of disability (e.g. poliomyelitis) began skiing, using the technique developed for the amputees (Pringle, 1987). It was also in this same period that this sport began to gain more attention when the amputees began experimenting with prosthetic skiing and the visually impaired started to participate in this kind of activity. In the late 1970s, the most important innovation was the development of a technique called "Four-Track", which allowed many people with severe deficiencies to ski. In the 1980s, a new technique was developed called “sit-skiing” (Pringle, 1987). This allowed the participation of people who were wheelchair bound to take part in this type of sport.

6.2.2 Monoski, Sit-skiing, and Other Variant Techniques

The initial definition of monoski is linked to the equipment used and the way that the individuals position themselves when skiing. Therefore, an amputee skier with only one leg and skiing on foot will be practicing monoski. However, a new meaning was given to this definition when the amputee was able to use a monoski in the seated position (Fig.46, Annex 7). In 1975, a patent was given for a piece of sports equipment called the “Snow Monoski”. It is a monoski that can be used by anyone that is in the seated position and who can then control their speed, direction and braking. This equipment consists of a ski with curved side edges, which in turn supports an articulated structure that gives support for a seat. The Snow Monoski was developed without devices for the control of direction in order to decrease its weight and potential additional risks (Fabris, 1975). Another type of equipment was later developed called a “Ski for the handicapped” (Fig.47, Annex 7), that is made up of a cell similar to a kayak, mounted on top of one or two parallel skis, where the individual can sit and accommodate the legs (Olpp, 1986).

Sit Skiing

This technique has been used by people who are unable to ski in the standing position, such as those who have muscular dystrophy, multiple sclerosis, cerebral palsy, paraplegia and tetraplegia. It has been adopted since 1980. The way to change the direction of the device is through a lateral inclination of the body and by the contact of the ski and outriggers with the snow, on the same side as

the desired direction (Fig.48, Annex 7). Another way of turning at an early phase of the learning process is through a guide positioned behind the learner, and who intervenes in a manoeuvre when needed. The sit-skiers have become very proficient in many different situations, without requiring the direct intervention of the instructor, which characterises an important aspect of the relationship between the sport and the positive effects it has on improving motor, psychological and motivational conditions. The use of the Sit-Ski/Monoski requires upper body strength, which makes it more difficult for people that have high paraplegia or those that are tetraplegic.

Four Track Skiing

This name is derived from the track that is left in the snow. It requires two skis and two outriggers and has been used for people that need assistance to move around or who have poor balance control. However, they can still ski in the standing position, even without having total motor control of the legs to ski without any kind of support.

Three Track Skiing

This technique requires one ski and two outriggers and its name comes again from the type of track that is left in the snow. It has been used by people in the standing position that do not have one of the legs or feet to ski. The sit-skiers also use this technique as they ski with a monoski and two outriggers.

“One” Track Skiing

Some experienced skiers that use the previous technique, have learnt to ski using ski-poles and do not require the outriggers, which in fact was the only possibility for people with just one leg to ski before the creation of the outriggers.

6.2.3 Bi-Skiing

Other possibilities for adaptation of the technique and equipment are available for people with special needs for the practice of alpine skiing. The Bi Ski is a piece of equipment with two long skis and because it is close to the ground, it does not require long outriggers (Fig.49, 50 Annex 7). It is an option that provides greater ease of use. Skiers with not much upper body strength and who have poor control of the trunk, such as those with high paraplegia or tetraplegia, can better adapt to this type of technique.

6.2.4 Recent Sit-ski Development

The most recent sit-ski model adapted from a monoski is made of carbon fibre and weighs approximately 13kg. Its use is more difficult for WC dependent people as it requires more muscle strength to manoeuvre than the other previously developed devices. However, individuals that use wheelchairs for their mobility and training, and are capable of developing the strength and equilibrium of the trunk and upper body muscles are more suited to using this equipment and its respective technique.

The frame is made of a resistant metal alloy and has a shock absorber system of adjustable springs placed below the sit-ski shell, which plays the same role as the legs of someone without motor deficiencies (Fig. 51). The height and width of the seat can be adapted to the dimensions of the user and the foot support has infinite adjustment possibilities. At the base of the sit-ski, the binding plate perfectly simulates a ski-boot which makes the equipment compatible with any make of ski. The sit-ski also provides thermal comfort. An external fairing covers the legs, protecting them from the wind and snow, whilst at the same time giving a better aerodynamic function for the entire sit-ski/skier. On the inside part there is also a coating used to improve the comfort of the person while seated.

Figure 51: 1. Two parallel swings provide optimum shock absorption. Both pull and pressure are adjustable. 2.

The binding plate perfectly simulates a ski boot, making it compatible with any make of binding. 3. Foot fairing and foot fairing cover for seat widths.

6.2.5 Mechanical Aspects of the Sit-ski to be considered

In its most primitive design, a sit-ski is composed of a frame attached over a ski (Fig.52, 53, 54, Annex 7). A seat is mounted on top of this frame in such a way that it has a rotational axis that is above and perpendicular to the plane of the ski, allowing the seat perform a trajectory arc above this axis. The shock absorbers have one end that is connected to the seat support, which is placed between the seat itself and the axis of rotation, and the other end is fixed to the base of the frame.

Consequently, the movement of the seat causes compression or stretching of the shock absorber. The proportion of the seat movement in relation to the compression of the shock absorber is approximately 3.5:1 (La Come, 2000).

For the development of new equipment it is important to consider its evolutionary process and aims. From the 1980s new alternatives were being developed for sit-skiing with an emphasis on sports performance. The functionality and usability of new materials have been tested and used in the construction of the structure and mechanical function of the sit-ski, aimed at improving safety, performance, comfort, ergonomics, versatility and weight of the equipment, as well as the interaction between user and the equipment. The biggest advantage is that performance has improved and that the athletes can move progressively quicker. The disadvantage is that there has been an increase in the risk of more severe accidents.

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The development of adapted equipment, even though more expensive, is prioritised for elite athletes that help researchers to develop technological innovations for more efficient products that can subsequently be produced on a large scale by industry for people with disability. This provides them with sports alternatives and better access to the same equipment and opportunities offered to elite athletes.