Today's sport wheelchairs let athletes with disabilities play hard and fast.
There was a time when people confined to wheelchairs didn't go out in public. Franklin D. Roosevelt, for example, took great pains to make sure he stood for public appearances, even though he was usually confined to a wheelchair.
The story is different today. People with all types of disabilities lead active lives and participate in many activities, including athletics. In fact, wheelchair sports have become increasingly competitive and popular throughout the world.
Wheelchair sports formally started sometime after World War II when wheelchair-bound veterans sought ways to spend pent-up energy. Common games included table tennis, bowling, volleyball, catch, and pool. Basketball quickly became a popular favorite and the first basketball league began in 1946 in Veterans Administration Hospitals.
In the early days, everyday chairs were modified to fit each contest. As the different sports evolved so did the chairs, so much so that now a whole market designs and builds sport wheelchairs. Each sport has several designs and the chairs are often custom made to the user's body.
Contact-sport players drive their chairs hard and demand maximum performance in games such as rugby, hockey, and football. Wheelchair rugby, for example, was originally called "murderball" because of its aggressive nature. An integral aspect of these chairs, according to John Box, founder and president of Colours in Motion, Anaheim, Calif., is "an offensive shape that minimizes interference with other players on the field."
According to the U.S. Quad Rugby Association, wheelchair rugby, also called quad rugby, has roots in wheelchair basketball and ice hockey. Players must have a combination of upper and lower extremity impairment to be eligible to play. Each player is classified into divisions based on level of ability.Four players from each team pass a volleyball back and forth on a regulation basketball court and score by crossing an 8-meter goal line. They must pass or dribble the ball every 10 sec, and the player with the ball has 15 sec to advance the ball into the opponent's half-court.
Rugby players use sport-utility wheelchairs, like the Hammer, a contact-sport chair from Colours in Motion. The Hammer's frame is made of large-diameter 6061-T6 aluminum tubing. Its athletes have ridden it against chairs made of chrome molybdenum, titanium, and other aluminum grades and come out with no fatigue or damage.
The Hammer is custom made to a user's requirements because how the players sit in the chair affects performance. For instance, a low center of gravity makes the chair more stable. Other important features include adjustable seat height, overall height, frame length, seat angle, and backrest.
Wheel camber is another critical and adjustable part of a sports chair. It's the angle the wheel makes with the ground. The typical wheelchair with it's up-and-down wheels has 0° camber. When a chair so equipped is hit from the side, front, or rear, it is more likely to fall over, and also harder to turn. Adding camber to the wheels adds stability and easier handling.
Too much wheel camber, on the other hand, can be a problem. Wheels are less stable and energy is wasted trying to maneuver the chair. Too much angle also puts pressure on the side bearings and drag on the wheel. The optimal range of camber in the Hammer is between 0 to 20°.
The Hammer has an antitip bar at the rear of the chair with a revolving caster. It keeps the chair from falling over when hit in the front or sides. Should players find themselves tipped onto the rear wheel, they can still push on the hand rims to maneuver the chair. The position shortens turning radius and because the front wheels are off the ground, it turns faster.
Nothing but net
Basketball is one of the most popular wheelchair sports. According to the National Wheelchair Basketball Association, NCAA basketball rules apply with a few exceptions. For example, the chair is considered a part of the player, and an offensive player cannot remain more than 4 sec in the free throw lane while the player's team is in possession of the ball. A 30-sec shot clock governs offensive possessions and a player in possession of the ball may not push more than twice in succession with one or both hands in either direction without tapping the ball to the floor again. Taking more than two consecutive pushes is a traveling violation. A player may, however, wheel the chair and bounce the ball simultaneously just as an able-bodied player runs and bounces the ball simultaneously in regular basketball.
And as in regular basketball, wheelchair athletes demand excellence from their equipment. The TiSport BB from TiSport, Kennewick, Wash., for example, is built for action on the court. It's made from seamless titanium tubing that makes it shock absorbent and lightweight, about 19 lb. Tests show titanium is twice as strong as aluminum and half as light as steel. The reduced weight reduces shoulder wear and tear and wrist injuries, and gives more roll from minimal push.
The wheels of the TiSport BB use Spinergy Spox, which are wheel spokes made from Vectran fibers. Vectran, a material released by NASA, has better mechanical properties than Kevlar. The spokes help keep the chair lightweight, but also serve as a shock absorber. In fact, they are so resilient, that when the wheels are taken off and laid on the ground, a man can jump on the spokes and they retain their shape. And they can easily withstand impact from other chairs.
Another feature is a high-flange wheel hub, which connects the spokes to the axle. A high-flange hub has a bigger diameter so the spokes are shorter and stronger. Hand rims are used to push the chair and are made of titanium, which disperses heat from players' hands. The tires are sew-up designs that hold 230 psi, the highest tire pressure available on a wheelchair. They have low rolling resistance, which let them go farther per push than a standard tire.
For protection from other players, the TiSport BB chair has adjustable titanium front wings, which act as bumper guards and force opponents to keep their distance. They also protect the front casters. Like other contact-sport chairs, the TiSport BB has an antitip bar, and a camber range of 0 to 18°.
TiSport chairs are easily customized. "We use SolidWorks CAD software to automatically generate chair models," says Alan Ludovici, vice president of engineering. "Ten to twelve specifications are plugged into the program to generate a computer model. The software also creates documentation for the factory floor. This process will let users order the exact same chair years down the road."
Eat my dust
Racing differs from other wheelchair sports in that it pits individuals against other individuals instead of teams against teams. Players race each other on a regulation track,but must have specific size tires, brakes, and are allowed no more than one push-rim per wheel. Gears or levers for propulsion are not allowed.
A racing chair looks dramatically different than other sports chairs. It must have at least three wheels, one of which is smaller than the two drive wheels. The rider is positioned so their upper body is over the front wheel and can be in either a kneeling or sitting position, depending on the user's ability.
The Leader wheelchair, according to Bob Hall, founder and owner of New Halls Wheels, Cambridge, Mass., is the model on which other racing chairs are copied. What distinguishes the racing chair from other sports chairs is the unifork crown system. Instead of a handset in a regular bicycle, the body shape is forked and slips into a bushing and cap that holds it together. It is made from heat-treated 6061 T6 aluminum and weighs about 15 lb.
Another unique feature of the Leader is its steering mechanism, a spring-cylinder with center lever. It lets individuals push without having to steer in a particular direction. In the neutral position it acts like a tie rod, and in the turning position it's a spring. When racers need to pass somebody, or make a turn, they can steer with their hands left or right and when they let go the chair returns to a neutral position.Unlike the other sports chairs where players use their hands on the wheel rims to stop, the Leader has caliper brakes. They are similar to bicycle brakes and are applied to the front wheel.
The Leader also comes with a built in computer that records average speed, maximum speed, average time, and distance, so racers can continually improve their performance. And performance, after all, is the name of the game.
Wheelchair sports Web sites
To read more about rules, disability classifications, and teams, check out these sites: