Having spent the previous hour sitting still and engaging in calm conversation, Tinker Hatfield suddenly jumps off the sofa in his London hotel suite and shifts his weight on to the balls of his feet. The idea is to demonstrate how, with the right trainers, humans can be made to move like velociraptors. "For Jurassic Park," he explains, "we did shoes for the actors who were inside some of the dinosaur costumes. They had to be up on their toes like this, because that's sort of the shape of a dinosaur leg. So we designed special shoes to help them."
The prehistoric high heels came before the futuristic footwear 47-year-old Hatfield made for Jodie Foster in Contact, but after the hoverboarding boots he designed for Michael J Fox in Back to the Future II; after the bat boot in the first Batman movies, but before the shoe that has just been turned down for the new Superman movie. When you are universally regarded as The Man Who Invented The Trainer, you get asked to do these things all the time.
No one would contend that sports shoes did not exist before Hatfield began designing them for Nike 14 years ago. What is certain, though, is that he was the creative force behind the all-singing, all-dancing, deeply desirable trainer we now take for granted. He shifted the focus of sports shoe consumers from function to form, and from sport to street: "When I started designing shoes in late 1985, athletic shoes were just basic performance footwear. There was no romance, no tying in with athletic personalities, no design inspiration from outside. They were just done for sports. Then Nike came on the scene."
More to the point, Hatfield came on the scene. He revolutionised the design of trainers - and their desirability. Much of Nike's success in the 1990s has been down to his designs, especially the airbag technology that propelled Nike to the No 1 position in the market. Any new shoe he makes gets snapped up by devotees.
Hatfield, who is in London to promote his new Cross Trainer II, available next month, came to shoe design by an unorthodox route. In Oregon, as a teenager, he distinguished himself at basketball, hurdling and American football, then studied architecture at the University of Oregon. In 1981, he joined Nike, designing offices and showrooms, but always thought he could do shoes. "I understood them. I could tell Nike was starting to plateau and go down. Basically we ran out of consumers. Only so many people actually go running. So while the market grew, it wasn't going anywhere. People were wearing them around because they were comfortable, not really for style so much."
After four years, Hatfield became involved in designing the footwear itself, and made his mark with the "Air" bubble: a small plastic window in the sole of the shoe which allowed you to see the cushioning system inside. "My first shoe of any note was the original Air Max," he recalls. "The Georges Pompidou centre in Paris changed architecture, because it took the skin off the building so you could see inside. With the airbag, that first Air Max was like the Pompidou centre. Nobody had even thought of that in athletic footwear. It was an immature field of design. It was more like engineers were doing it."
Hatfield let his imagination run wild. "I treated designing shoes like designing buildings. A church is a good example of a building that's more than a building. Churches need to evoke emotion. They make you feel small, make something else feel bigger, more glorious. There's a lot of tricks in architecture to do that, and that's what I brought to footwear."
Other events conspired to take the trainer beyond the orbit of athletic training. Nike signed up-and-coming basketball star Michael Jordan, and Hatfield worked on his shoes. This marked the beginning of the modern cult of the trainer: expensive, ornate and collectible. The mania reached a macabre peak in the early 1990s when urban American schoolchildren were murdered for their shoes.
Hatfield says he and Nike were able to drastically reshape our perception of the trainer. "It added value to the whole idea of buying shoes. You're not really buying a piece of leather with some rubber and foam; you're buying a part of modern culture, a part of some personality. You're buying a thought, a way to express yourself. And the advertising really had a big impact. It made people lust after these things more than just needing a pair of shoes to go work out in."
In 1996, the brash green-and-grey Air Max 95 was adopted by designers to accompany their haute couture on the catwalks, as if they were conceding defeat to the superior styling of the mass-market sports shoe. Hatfield, too, has benefited from trainers' elevated status. In 1997, Forbes magazine named him one of the 20th century's 100 most influential designers. A new generation of product designers who grew up wearing his shoes have acknowledged his influence on their own work. "I'm contacted by museums all the time; people are collecting this stuff and there are articles and books being written about shoe design."
Unfortunately for Nike, this has resulted in a levelling off of sales and cultural excitement about trainers. Hatfield cites the decline in athlete worship and fashion's return to simpler designs as the obvious explanations. It's why he's crossed the Atlantic to promote his new design, a shoe with Pradaesque clean lines outside, and all the technology hidden within. "It's like sorbet," he says. "It cleanses the palette after all these over-designed shoes. Until you have the Next Big Thing, maybe you should downplay it a little, go a little more sophisticated."
The sentiment will be enough to reduce those of us reared on huge, elaborate Tinker trainers to tears. Surely he's not saying there will never be another Big Thing? "No," he says. "I think these things are cyclical. I think we're due for a leap."
That gives you plenty of time to start saving for the mould-breaking Air Jordan XXXVI.