The executive in charge of innovation at Nike believes the shoemaker’s path back to cultural relevance starts in the lab. Chief design officer Phil McCartney is pushing for “epic” breakthroughs to reverse a slide that erased $5 billion in revenue last year and forced a change of CEO. The company’s bets include shoes that use pressure points to stimulate the brain and jerseys that regulate body heat. But its most ambitious endeavor might be Project Amplify, a motorized shoe years from release that would help casual athletes and mobility-impaired people move faster.