The American banished the belly-roller technique with his victory at the 1968 Olympic Games.

Born in Portland, Oregon, in 1947, Fosbury became one of the most influential athletes in track and field history by developing the innovative high jump technique that transformed his sport in the 1960s.

In later years he often said that at the start of his high-jump career, in high school, he was the worst jumper in his school, in the school’s conference and in all of Oregon. He was seemingly not even a gifted athlete, having failed to make his school’s football and basketball teams.

In the high jump, he initially used the old-fashioned scissors style, in which the athlete runs at the bar and hurtles over in a roughly sitting-up position, kicking one leg after the other over the bar.

One day, Fosbury felt inclined to experiment with a new method: trying to clear the bars with his hips. The Flop began coming to him naturally. Coaches were not so sure: They would check the rule books to make sure it was legal, warn him that he could hurt himself doing it or simply assert that it was not a winning strategy.

Fosbury ignored the advice. He improved his personal best by an entire foot in high school alone. He began training harder and discovering a new joy in the sport.

“When you reached the elite level in the high jump, going over the bar at those high levels, you really feel like you’re flying,” he told The Times in 2002. “You’re up there for only a second, but time really does begin to slow down. Time expands. The mind does amazing things. And at that level, it’s truly 90 percent mental and 10 percent physical.”

It was not just Fosbury’s form that made him an unconventional athlete. He wore mismatched running shoes. He had the arm muscles of a chess player. Before making an approach run, he rocked back and forth, clenching and unclenching his fists.

He graduated from Oregon State University in 1972 with a bachelor’s degree in civil engineering. He moved to Idaho, where he founded an engineering company. His jobs included designing and building bike trails and running paths. He ultimately became a zoning commissioner of Blaine County, Idaho.

Writing on Instagram, Fosbury's agent Ray Schulte said his client had died on Sunday.

"It is with a very heavy heart I have to release the news that long time friend and client Dick Fosbury passed away peacefully in his sleep early Sunday morning after a short bout with a recurrence of lymphoma," wrote Schulte.

"Dick will be greatly missed by friends and fans from around the world. A true legend, and friend of all."

"Our sport lost a true legend and innovator with the passing of Dick Fosbury," said the USA Track and Field (USATF).

"He invented the "Fosbury Flop", was a gold medallist at the 1968 Games, and remained an advocate for athletes his entire life. Fosbury's legacy will live on for generations to come."

USATF chief executive Max Siegel said he was "deeply saddened" by Fosbury's passing and called him a "true legend and pioneer in the world of track and field".

He added: "We will always be grateful for his contributions to the sport and his impact on generations of athletes who followed in his footsteps.

"Dick will be deeply missed but his legacy will live on as an inspiration to all."

Revolutionary technique

Prior to Fosbury's emergence, almost all high jumpers attempted to clear the bar by using the belly-roll technique, in which they rose face-first while attempting to turn their body mid-jump over the bar.

Instead of attacking head first, the lanky 1.93m tall Fosbury would arch towards the bar on his run before jumping backwards and flopping onto the mat, which is still the standard technique used by elite high jumpers today.

This form is more effective from a biomechanical point of view, as it allows less space between the jumper's centre of gravity and the bar to be cleared, thus gaining height.

Fosbury began experimenting with new forms of high jumping while still at school, but his new approach first attracted worldwide attention in 1968.

At the 1968 Games in Mexico City, Fosbury won the gold medal after clearing 2.24 metres on his third jump, a new Olympic record, beating teammate Ed Caruthers (2.22), while Soviet athlete Valentin Gavrilov (2.20) took bronze.

A 'mediocre' but great jumper

The world record had been held by the Soviet Valeriy Brumel with 2.28 since 1963, using the belly roll technique.

Although Dick Fosbury was never able to clear that height - in fact he tried unsuccessfully on that magical day in Mexico City with three failed attempts over 2.29 - and although there were many sceptics who doubted the effectiveness of the new method, it quickly gained popularity, and in the following years more and more jumpers, men and women, started to use it.

Already at the 1972 Games in Munich, 28 of the 40 competitors used the Fosbury technique, and at Moscow 1980, 13 of the 16 finalists did so as well.

Moreover, only two other jumpers managed to win an Olympic medal using the belly roller since Fosbury's innovation, who was inducted into the US National Track and Field Hall of Fame in 1981.

"The current popularity of my style is a wonderful reward for how much I had to put up with in the beginning with a style that nobody liked," he said in 1984.

"I used to jump backwards in high school and everyone laughed at me, considering me a crackpot and some people a snob for breaking away from the known rules.

"Until I won in Mexico in 1968 and became a hero."

With the 'Fosbury Flop', Cuba's Javier Sotomayor soared over 2.45m in 1993 to set the world record and set one of the longest records in athletics history in Salamanca.