Canadian Karen Cockburn performs in the trampoline individual competition of gymnastics during the XVI Pan-American Games Guadalajara 2011 in Guadalajara, Jalisco, Mexico on October 17, 2011. (HECTOR GUERRERO/AFP/Getty Images)

Previous features: Modern Pentathlon | Steeplechase | Synchronized Swimming | Rhythmic Gymnastics | Lost Events

By Mike Tierney, Special to Universal Sports

For generations, our awareness of trampolines was limited to the backyard bouncing exercise that engaged, exhausted and occasionally injured hyper-active youngsters.

Then, at the dawn of a new century, we tuned into the Olympics and were startled to discover that a recreational activity widely equated with tag-you’re-it and dodge ball had been added to the Games menu.

Olympic authorities, capitalizing on the popularity of gymnastics, introduced trampolining in Sydney, with similar rules to the sport that put Mary Lou Retton and Nadia Comaneci on cereal boxes.

London marks trampolining’s fourth appearance in the Games, making it 12 years old in Olympic years — about the same age as a typical bouncer on the old backyard mat.

HOW IT WORKS: The 16 competitors in the men’s and women’s divisions complete 10 elements, each involving a somersault, while landing within a narrow “jump zone” in the middle of the mat. Athletes must keep their feet and legs together.

Judges issue a score for each routine. Athletes with the eight highest scores advance to the final round.

HISTORY LESSON: Not much at the Olympics, given that trampolining made its debut in 2000.

The sport’s roots are in the 1930s, when the aspiring acrobat/gymnast/inventor Larry Griswold used newly developed fabric and materials to create the model used today. He and colleague George Nissen would work out with trapeze artists, helping them repair torn nets. Thus came the inspiration to create the trampoline. The first known textbook covering the sport was published in 1942.

Among the early practitioners of non-competitive trampolining were World War II pilots, who practiced remaining oriented in mid-air.

FIRST OF ALL: With the 86-year-old Nissen in attendance, it was appropriate that a relative old-timer came out of retirement to claim the first men’s gold. Aleksandr Moskalenko of Russia had given up trampolining three years earlier.

REMEMBER THAT?: In 2004, the youngest entrant, 18-year-old Huang Shanshan of China, took the bronze after reigning Olympic queen Irina Karavayeva was unable to finish the voluntary portion of her routine in the preliminaries.

In 2008, the judges mistakenly thought Henrik Stehlik of Germany, who had earned a bronze four years earlier, missed the jump zone and kept him from progressing beyond the qualifying round. Video replays would have supported his protest, but they cannot be considered in official reviews, so his score stood.

WHO’S GOT THE POWER: That would be China, which is amazing because it was a stranger to the sport until the late ’90s, but not so amazing because the nation has a track record of rapid improvement when it pours resources into any endeavor.

Once its national team was formed in 2002, two years after trampolining’s Olympics break-through, China began watching video of competitions, imported foreign advisors and transferred coaches from its accomplished gymnastics program.

Since the 2008 Games, it has hogged all of the men’s and women’s gold medals at the annual world championships.

STAR-GAZING: Karen Cockburn of Canada has hauled off a medal — one bronze, two silver — from each Olympics. The 13-time national champion, who took up trampolining as a training tool for gymnastics and diving, can become the first medalist from her country in four different Games.

The leading candidate for stardom on the men’s side might be a two-time world champion from China with the euphonic handle of Dong Dong. Showing considerably more imagination on the mats than his parents did in naming him, Dong figures to better the bronze he won in 2008.

Defending women’s champion He Wenna will contend for another gold, provided she has recovered emotionally from her breakup with gymnastics standout and countryman Yang Wei.

U-S-A, U-S-A: No American has lasted into the Olympics’ final round. The U.S. has qualified athletes in each gender for London. The highest ranked male is 26th, female 27th.

AND THE NUMBER IS … 300,000: The estimated amount of injuries connected to trampoline use in the U.S. each year, according to the American Academy of Orthopaedic Surgeons. Onlly about four percent result in hospitalization.

OLYMPIC DATES: Aug. 3 (men), Aug 4 (women).