Issue link: https://viewer.e-digitaledition.com/i/918219
78 runninginsight.com ©2017 Formula4media LLC. points out, for example, that the location of the flex point along the length of the foot can vary by up to 10mm for the same size foot, so designing a controlling strap to fall precisely behind that point can be problematic. Designers use multiple strategies to create an adaptive fit that can accommodate the spectrum of feet. Laces are the traditional solution and continue to work admirably. "You have the ability to do almost an infinite number of different combinations that somehow will make the shoe fit for you," says Bartold. Companies continue to refine lace thickness, stretch and friction, along with the placement of eyelets to create the desired hold in the proper location. The most extreme example is Puma's Netfit design that allows laces to connect and wrap anywhere on the upper. Saucony's ISOFIT is an example of creating adaptability beyond laces, changing the traditional midfoot saddle into a set of "fingers" that can move up and down the foot to the desired hold location and independently rise or lower over the shape of the instep. Boa is working with several companies to create uppers that adapt to your foot shape and then cinch down precisely with their cable-and-dial system. Others are using stretchy materials to adapt to different foot shapes, providing comfort at the cost of snugness. "Stretch makes it easier, like sweat pants," says Gray. "But a tailor can take normal pants and make them fit right, and you can move." Vive la Différence Those tailored pants, however, would only fit and move on you, not on your neighbor. In the end, no matter how adaptive uppers become, the true source of fit comes from the shape, which is designed by the last the shoe is built upon. NEW BALANCE 1500 T2 Independent fingers mold to the shape of your arch and instep as they are locked down with Boa's new lighter and more flexible system using textile cables, nylon/ Teflon guides and low-profile dials. Boa is working with multiple shoe designers to create uppers that use their closure technology for a secure and precise, while still adaptable, fit.