The running industry wants to put a spring in your step — literally.
The latest running-shoe technology boasts cushy, supportive foam midsoles, uppers knitted with a single string of yarn, and soles made from plastic blades that propel you forward with each step.
Greg Zuckerman, footwear buyer for Boston-based City Sports, said the shoe industry is finding new ways to tailor shoes to runners’ body movements.
“They’re really looking at the biomechanics of a runner and coming up with innovative solutions to problems and innovative technology that increases performance through geometry,” Zuckerman said.
The newest of the crop is the Fresh Foam 980, a New Balance shoe released last week and priced at $110.
The Boston shoemaker has been measuring the forces and pressures on the human foot as a runner hits his stride, and from that designed New Balance’s softest running shoe yet. The key is a midsole made of a single piece of lightweight yet strong foam shaped to provide more cushion in the front and more stability at the heel.
Claire Wood, senior product manager for performance running at New Balance, said the technology enabled the company to develop a soft shoe that has enough stability that runners should not be at greater risk of injury.
“The reason why we took so long to go to market with this is that with a soft shoe you want it to perform just as long as a firm shoe and not have it break down quicker,” Wood said. “So many runners want a soft shoe and then learn they can’t have it. We wanted to make it possible for the runner, through science, to have an experience that wasn’t possible before.”
Meanwhile, rival Nike in Portland, Ore., has a more radical step-up: The entire upper portion of the shoe, above the sole or bottom, is knit from a single strand of fabric.
Typically, running shoes are assembled from different materials that are cut and stitched together, from leather or nylon to plastic supports and mesh cloth. But the Flyknit Lunar2, an updated version on its best-selling running shoe, features strands of polyester yarn knitted in various layers to the shape of a standard running shoe.
The technology not only changes the way running shoes are manufactured but makes for a much lighter shoe: At 8.4 ounces, the men’s Flyknit Lunar2 is about a half-ounce lighter than the New Balance Fresh Foam 980.
“It’s by far the most comfortable upper that you’ll put on,” said Zuckerman, the City Sports buyer.
The Lunar2 has more structure than its predecessor, as Nike wrapped more fabric around the arch of the shoe. Zuckerman said the upper feels like a plush sock, but the midsole offers the stability of a trainer. The shoe retails for $150.
The German shoe giant Adidas may have the most unusual-looking shoe of the lot: the Springblade, which features a series of toothlike blades made of high-performance polymer bonded to the bottom of the shoe.
From a slight distance, the blades give the shoe the appearance of being mounted on a platform.
On the newest model, the Springblade Razor, the 16 blades are roughly one-eighth of an inch thick, with some variance. The blades are shorter and thinner at the forefront of the shoe and become progressively larger toward the heel. Each blade is placed at a different angle to provide a natural landing for the runner’s feet.
Robbie Fuller, Adidas design director for advanced concepts, said the blades collapse under pressure and then expand upon release to spring the runner forward.
“You’re springing up like you’re on the blocks with each step,” Fuller said.
Adidas also expects the blade material to last longer than shoes made with standard UVA foam. The Springblade Razor is priced at $180.Taryn Luna can be reached at email@example.com. Follow her on Twitter @tarynluna.