Sometimes innovation comes from improving on an existing product. Sometimes, the game has changed so much that it’s better to start from scratch. Case in point is the Adidas Adizero Prime SP, an innovative sprint shoe that many of the world’s top athletes are wearing at the 2012 London Olympic Games.
“In the past, it’s been kind of an evolutionary process,” says Faculty of Kinesiology researcher Darren Stefanyshyn, who helped design the shoe. “This time we tried what I would call a more revolutionary process. Instead of looking at existing sprint shoes and saying, ‘What can we make better and change?’ we said, ‘Let’s start from scratch and take away everything and decide what we really need for a sprint shoe.’ So, we basically started with the question, ‘What is the function of the shoe? What does it need to provide and how do we actually end up doing that sort of thing?’”
Years of research in Kinesiology’s Human Performance Lab (HPL) told Stefanyshyn the shoes obviously have to provide traction, a landing or guiding surface and stiffness at the Metatarsophalangeal joint of the foot.
“We have strong documented evidence that by increasing the stiffness of the shoe, you can increase performance. The problem with doing that is that you usually wind up with a much heavier shoe and it’s a tradeoff between mass and stiffness,” Stefanyshyn says. “Adidas came up with carbon nano-tubes that provided a lot of stiffness but are much lighter. They’re basically twice as stiff as a typical carbon plate but half as thick, so the mass is very, very low.”
The shoe has a number of other innovative features – the upper is made with a new welding mesh technology that eliminates pressure points and is also very light. New nano-composite ‘spikes’ don’t actually penetrate the track, they provide compression, which produces traction without losing energy from having the spikes actually pulling in and out of the track surface.
Many of the other innovations come from Stefanyshyn’s biomechanical analysis of what a sprinter needs.
The end result is a shoe Stefanyshyn says is even better than he imagined, and the world’s athletes seem to agree. He says the first run of the elite level shoe sold out “almost overnight,” which is a gratifying vote of confidence for the biomechanics researcher.
“I’m lucky – I get to play a lot and I get to play on fun and exciting things.”