Trampoline
From Wikipedia, the free encyclopedia
- For alternative meanings, see Trampoline (computers), Trampoline_(multihulls) or Trampoline (horse).
- For more information on the gymnastic sport, see Trampolining.
A trampoline is a gymnastic and recreational device consisting of a piece of taut, strong fabric stretched over a steel frame using many coiled springs to provide a rebounding force which propels the jumper high into the air. In a trampoline, the fabric is not elastic itself, the elasticity is provided by the springs which connect it to the frame.
Contents |
[edit] History
[edit] Early trampoline like devices
It could be said that a kind of trampolining was done by the Inuit people who used to toss each other into the air on a walrus skin, something like the sheet used by firemen to catch people jumping out of burning buildings.
There also is some evidence of people in England having been tossed into the air by a number of people holding a blanket.
These may not be the true antecedents of the modern sport of trampolining, but it is certain that in the early years of the 20th century some acrobats used a "bouncing bed" on the stage to amuse audiences. The bouncing bed was in reality a form of small trampoline covered by bedclothes on which the acrobats performed mostly comedy routines.
According to circus folklore, the trampoline was supposedly first developed by an artiste called Du Trampolin who saw the possibility of using the trapeze safety net as a form of propulsion and landing device and experimented with different systems of suspension, eventually reducing the net to a practical size for separate performance. While there were trampoline like devices used for shows and in the circus, the story of Du Trampolin is probably a myth and no documentary evidence has been found to support this.
[edit] The modern trampoline
The first modern trampoline was built by George Nissen and Larry Griswold around 1934. Nissen was a gymnastics and diving competitor and Griswold was a tumbler on the gymnastics team, both at the University of Iowa, USA. They had observed trapeze artists using a tight net to add entertainment value to their performance and experimented by stretching a piece of canvas, in which they had inserted grommets along each side, to an angle iron frame by means of coiled springs. It was initially used to train tumblers but soon became popular in its own right. The name comes from the Spanish trampolín meaning a diving board. George Nissen heard the word on a demonstration tour in Mexico in the late 1930s and decided to use an anglicized form as the trademark for the apparatus.
In 1942 Griswold and Nissen created the Griswold-Nissen Trampoline & Tumbling Company, and began making trampolines commercially in Cedar Rapids, Iowa.
During World War II, the United States Navy Flight School developed the use of the trampoline in its training of pilots and navigators, giving them concentrated practice in spatial orientation that had not been possible before. After the war, the development of the space flight programme again brought the trampoline into use to help train both American and Soviet Astronauts, giving them experience of variable body positions in flight.
The competitive gymnastic sport of trampolining has been developed and it has been part of the Olympic Games since 2000. On a modern competitive trampoline a user can bounce to a height of up to ten metres. Trampolines also feature in the competitive sport of Slamball, a variant of basketball, and Bossaball, a variant of volleyball.
[edit] Trampoline construction
There are two types of trampoline, recreational and competitive.
Recreational trampolines are less sturdily constructed and their springs are less strong. They may be of various shapes, though the most usual are circular, octagonal or rectangular. The fabric is usually a waterproof canvas or woven Polypropylene material.
The frame of a competitive trampoline is made of steel and can be made to fold up for transportation to competition venues. The trampoline is rectangular 14 feet by 7 feet in size. The bed is made of a strong fabric. The fabric can be woven from webbing or from individual thin strings as in a Ross (or "Two-String") bed.
In any trampoline, the fabric bed is not elastic itself, the elasticity is provided only by the springs.
The Springfree Trampoline uses fibreglass rods instead of springs to create the rebound effect. It is claimed to be a safer alternative to the traditional trampoline.
[edit] Safety
Using a trampoline can be unsafe, and in organized clubs and gyms there are usually spotters placed at each corner of the trampoline to try to break the fall of any athlete who loses control and falls. The majority of injuries happen on privately owned home trampolines. Bouncing off a trampoline can result in a fall of three or four metres from the peak of a bounce to the ground or a fall into the suspension springs and frame. There has been an increase in the number of home trampolines in recent years and a corresponding increase in the number of injuries reported leading some medical organizations to suggest that they be banned. [1]
Most authorities recommend that only one person should be allowed to jump at a time to avoid collisions and people being bounced in an unexpected direction. It is possible to reduce the dangers by burying the trampoline so the bed is closer to the surrounding surface so any fall is less and having that area padded. Having some training in a gym may also be beneficial in alerting people to possible hazards. [2].
Recently kits have been sold for home trampolines that form a wall around the trampoline and prevent users from bouncing over the edge, and sometimes pads are added to cover the springs. While these nets do prevent jumpers falling off the trampoline on to the ground, these are not the most common type of injury. Some people consider that these nets may actually increase injuries as jumpers can be entangled or stopped from landing on their feet by impacting the net. [citation needed]
[edit] Mini-trampolines
Small, usually round, trampolines (less than 1 metre in diameter) are often used as part of a physical fitness regime. They allow the user to gain many of the benefits of exercise with a low impact on knees and joints. This type of trampoline is usually kept in an indoor environment. These trampolines do not give a rebound as high as larger size recreational or competitive trampolines.
