Footwear Insight

footwearinsight.com January/February 2018 ~ Footwear Insight • 57 I n the four decades since the invention of the running shoe, most of the industry's atten- tion has focused on the midsole. After all, conventional wisdom maintained that the sole determines how the foot interacts with the ground, cushioning and controlling as necessary to protect and enhance your stride. Differences in sole density, shape and materi- als have defined the categories we talk about to differentiate running shoe models. Recently, however, voices in science and medicine have questioned whether our prescriptions based on soles and the devices we build into them actually work. A new model posits that the best way to choose a shoe is to find one that feels the most comfortable throughout the stride, enhancing and supporting your natural, preferred movement path. With the role of the sole in decline as the single dis- tinguishing factor between running shoes, the upper is receiving increasing attention — and rightfully so. In his on-foot shoe testing at his Heeluxe lab in Santa Barbara, Geoffrey Gray has observed that uppers affect function far more than previously understood. Given two shoes that have identical midsoles, outsoles and insoles, but different upper shapes, he finds, "People will always identify that the fit is the same, what they identify is different is flexibility, cushioning, stabil- ity." And it's not just perception: A 2017 study out of Brazil revealed that different shoe uppers created more consistently measurable changes in runner's biomechanics than different midsole materials. Holistic Comfort "The upper is about fit," says podiatrist, biomecha- nist and Salomon shoe consultant Simon Bartold. "Which means it is incredibly important, because fit equals function. If it doesn't fit properly it doesn't work properly." Jonathan Tiepan, senior footwear product line manager at Salomon, adds, "The upper might have more to do with your preferred motion path than the bottom." Designers are increasingly realizing that the shoe works as a unit. "You can't look at the bottom as completely separate from the upper," says Under Armour's chief design officer Dave Dombrow. "How you solidify some zones, how you let other zones stretch, and how that interacts with the forces on the bottom — it's all one thing." Kurt Stockbridge, footwear development VP at Skechers Performance, agrees. "It's much more holistic than people know," Stockbridge says. "It's not about this and that, but how everything comes together. Comfort: you can't define it — it is everything." Moving Parts At the very basic level, the upper's task is simple. "The primary purpose of an upper, where it can't fail, is to hold you on the footbed," says Stockbridge. "The rest is all bonus." Complicating this seemingly simple task is the fact that the shape of the foot changes as it moves through the stride. The midfoot arches and elongates with each step. The ball splays and flexes. The toes lengthen. Muscles all around the foot contract and relax. "The variables are just massive," says Tom Garza, product VP–global footwear at 361°. "There are a ton of moving parts, and the foot operates completely different for everybody. How do we allow mobility to occur, but provide structure at the right places?" The first key to creating this dynamic fit is to know where you want to hold and where you want to give. Experts and designers agree that the primary location you need control is in the midfoot. "If you can lock down the fit over the navicular – the instep – everything else kind of works," says Gray. Stockbridge defines the key location more precisely as just behind the ball of the foot. They point to a sandal or flip-flop strap as a simple example of where the foot needs support to keep aligned on the sole. Importantly, however, this hold cannot extend for- ward around the ball of the foot, which needs space to expand and bend. Allowing more freedom for the front of the foot is one of the positive changes that came out of the minimalist movement. "If you compare shoes from a decade ago to now, one of the biggest changes in the upper is the fit from right behind the met-heads up through the toes," says Spencer White, VP of Saucony's Human Performance & Innovation Lab. "There's more room there, and that's a good thing. It never needed to be as restrictive as it was. It made the shoe less com- fortable, and for some people, having that grip made it impossible to run in the shoe." Altra's foot-shape design has taken this trend to THE RISE OF THE Today's emphasis on comfort puts the top of the running shoe center stage. By Jonathan Beverly UPPER 361°: SPIRE 3 Jacquard engineered mesh provides distinct zones of flexibility and support and eliminates the need for overlays. While the simpler upper adapts closer to the foot and lets it move more naturally, it still has an inner layer of soft webbing around the midfoot to hold the foot secure.

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