[Torsion --a new concept in construction of sports shoes. Motion excursion of the foot in athletic stress--anatomical and biomechanical observations and their effects on construction of sports shoes].

In recent years several construction elements resulted in an increasing stiffening of the sport shoe so that the foot was partly forced to make its own movements inside the shoe. A new sport shoe concept is presented basing on the results of anatomic and biomechanical studies, its innovative feature being decoupling of the foot movement between the calcaneal part of the foot and the metatarsus (= torsion). The foot is given an opportunity to transmit its freedom of movement in the longitudinal axis of the foot to the shoe without the shoe acting as a lever, this goal being achieved by a limited liberation of the metatarsal pronation/supination and a controlled uncoupling of the metatarsus from the calcaneal part of the foot.