A futuristic shoe with true energy return based on enhanced heel-lift, optimized shoe springs (40% reduction in maximum foot impact), practical precise automatic electronic gear changers, novel powerful shoe impact chargers, improved pulley electronic actuators, novel low-impact much stronger springs (featuring the novel use materials such as Kevlar, Spectra Shield, and fiberglass), novel remarkably stronger, more flexible, and tougher structures, and multiple designs for enhanced heel-lift and to prevent excessive toe sink. These designs require linkages and two improved hinges—one with enhanced natural hinges and a second with tied cogged hinges. There is a rotating-arms enhanced optimal spring, which when combined with the tied cogged hinges, results in optimal foldable arrays for deployment in outer space—and which gives a smart energy return knee brace. These novel capabilities promise a wide range of additional applications such as robotics, prosthetics, orthotics, springs, aerospace, automobiles, body armor, and earthquake retrofitting.