The present paper reviews the process of the development of a strength-training machine for the foot muscles, the scientific background and the exploitation of the patents. The prototype was manufactured by the mechanical department of the University of Duisburg- Essen and tested by biomechanical experiments in the Institute of Sport and Movement Sciences. In 2009 the machine was patented and in 2011 it was launched on to the health market. Meanwhile, it is used in strength-training facilities in several European countries. The invention is based on the anatomy of the subtalar joint which is located under the ankle joint. The subtalar joint axis has a unique orientation within the human body which is deviated from the longitudinal foot axis to medial and dorsal. A subsequent intervention study revealed the bio-positive effects of functional anatomic subtalar strength-training of the pronators and supinators on foot stability. Subtalar-specific strength increase is especially recommended for the prevention and rehabilitation of exercise-related injuries. Furthermore, subtalar muscle strength is found to determine the postural control during several standing positions. Therefore, pronator and supinator strengthening should be integrated into training programs to prevent falls in elderly people. The subtalar strength-training machine is one example of how the anatomical and biomechanical function of the human body is implemented in sports technology.