As spectators around the world watch the 2020 Tokyo Paralympic Games, they will see athletes using an impressive array of high-tech prostheses, wheelchairs and other assistive technologies. These devices have almost no similarities with the ones used daily-and they vary greatly between different sports.
“We design sports equipment according to the restrictions and needs of this sport to get the best performance,” explains Bryce Dyer, a sports technology expert at the University of Bournemouth in the United Kingdom, who develops artificial limbs for disabled athletes.
For example, blade prostheses-which are elastic to better store and release energy-are widely known in track and field competitions. However, lower limb amputees participating in bicycle competitions must perform different types of sports at higher speeds, so their prostheses have different requirements. “When you exceed a certain speed, one of the greatest forces is air resistance. The greater the resistance, the more you have to try to reduce and overcome it,” Dell explained. Non-handicapped legs “are not particularly aerodynamic; they are not designed for this task. But bicycle prostheses, we can design this way.” He created such an object, replacing the calf with a flat middle part. “We can make it very, very thin,” Dell said. “It’s almost like an airplane wing—the thickness of a razor—to cut the air. [and] Reduce or eliminate any turbulence in it. “For cyclist limbs, this flat part is oriented with the thin edge facing forward, which is the opposite of the blade prosthesis used for running, where the wide side does this.
Wheelchairs used for different sports are also very different, although they have some similarities. Many are made of high-tech materials, such as carbon fiber, making them both strong and light. They usually include rubber-coated wheel steering handles that athletes can hold with gloves to maximize friction. But other than that, the design is different. For example, in wheelchair fencing, the wheels are locked in place, and the athlete hits and evades from the set position. Therefore, the fencing chair is equipped with leg straps and strong handles to help athletes maintain a stable sitting posture. And many people’s backs are lower than usual to achieve more upper body exercises.
The basic shape of the fencing chair still looks a lot like an everyday wheelchair. But for a racing chair designed for high speeds, the situation is completely different. The third wheel on the front of this device can achieve a low and slender shape, which is most suitable for the athlete’s posture: kneeling and leaning forward. The spoke wheel is usually replaced with a smooth disc, which produces less air turbulence and reduces the force required for high-speed movement.
For sports that require more mobility, another design element is needed. “Your tires or wheels are actually tilted,” said Becca Murray, a retired American wheelchair basketball player who participated in three Paralympics and won gold medals in two of them. “Its power is that it can help you faster, and you can turn a dime faster, and your daily chair-it won’t make you turn so sharp.” The extra wheels on the back of the chair also help these fast Turn and increase stability. But such chairs can sometimes tip over, so the design must be sturdy. This is why athletes wear shoulder straps or belts on their hips and legs. “If you fall, you want to stand up right away,” Murray said. “So you want your wheelchair to stay attached to you, as if you were a person in a wheelchair.”
In addition to being suitable for a specific sport, the equipment must also meet the unique needs of each athlete. Ian Brittan, associate professor of disability and Paralympics at the Centre for Social Business Research at Coventry University in the United Kingdom, said: “Most of the equipment is custom made: it is designed to maximize the use of the athlete’s body.” For example, track and field prosthetic legs May or may not include mechanical knee joints. “Some runners, depending on the length of their limbs, if they have an above-knee amputation, they will increase their knee joints,” Dell said. “But there are some unique athletes. British athlete Richard Whitehead is a good example.” Whitehead had two knee amputations Formed his own running style-There is no need for knee joints at all. “It looks almost like an eggbeater, his legs swinging from side to side in the manner of an eggbeater, left and right,” Dell said. “It’s very unique to him.”
In athletes competing in wheelchairs, similar customization is necessary. For example, increasing the height of the backrest of the chair and the inclination of the seat, also known as “inclination”, can help compensate for abdominal weakness. “Actually, there is a small dump on my chair because I don’t have all the core muscles to help me maintain my balance,” Murray explained. “It just means that my knee is higher than where I sit, so it’s slanted.” Players with high spine injuries may not have as strong abdomen as Murray and need to tip over even in their daily chair. Other people with amputations or knee injuries may have more abdominal strength and don’t need to dump at all.
The technology seen at the Paralympic Games can improve the speed and mobility of sports-but it is unlikely to inspire a significantly different design for non-athletes. One of the reasons is that wheelchairs used in daily life have been optimized for other qualities, such as taking up as little space as possible. “You want your daily chair to be as small as possible, because in daily life, you have to walk through small places and doorways,” Murray explained. “You like it to be close to your hips, the wheels are straight up and down, so you can be as narrow as possible.” Many public spaces are built that simply cannot accommodate various wheelchair designs.
Price is another consideration. “You have to remember that the commercial market for elite athletes is very small, and in many cases, these athletes are sponsored,” Dell said. “So, just as IndyCar or Formula One technology eventually penetrates into everyday family cars, a certain degree of penetration is important. But sometimes it’s subtle.” For example, some prosthetic parts that are almost invisible-such as Connect the limb to the socket of the wearer’s body-may be improved.
In addition, Dell added that engineers and designers working with Paralympic athletes will learn some techniques that can be applied to other amputees. “It will actually provide prosthetics with the experience of how to install prostheses for those who are very active-they may want to jog for entertainment, walk the dog, play tennis or whatever-in this way to give them a higher level of comfort. ,”He said. “It’s not just about the appearance of things. It’s also about the experience that assistive technologies can be created and designed for prosthetics to allow people to perform certain types of activities.”