Impulse and Fatigue Damping Behavior of Shoe Soles and Athletic Footwear
Adidas® is one of the world's leading names in sports footwear and they treat the design and testing of their shoes seriously. One of their sports shoes, the EQT Solution, is built on a concept that Adidas calls The Feet You Wear. The design allows the foot to move naturally, protects it where necessary, and enhances the athlete's performance wherever possible. It means an effective cushioning system to protect the heel from impact forces and enhance the athlete's performance during push-off.
This advanced suspension system for sports shoes requires a relatively soft visco-elastic system under the heel, absorbing a high amount of energy during impact, while under the forefoot, a relatively soft elastic material is needed that doesn't dissipate energy. For this design, Adidas uses a visco-elastic AdiPRENE material in the heel at the point of impact and an elastic AdiPRENE plus material for push-off in the forefoot.
Like any high-tech suspension system, this one needs thorough testing. Adidas uses our 8516 testing machine with WaveMaker and MAX software to measure the "damping behavior" of the sole area of their shoes. The soles are subjected to hysteresis, loading and unloading tests produced by our 8500 servohydraulic controller. Typical load patterns are used to determine the dynamic stiffness and energy absorption when running and jumping in the shoes. These tests are part of a long-term research and development project to find the optimum absorption levels.