Foot injuries and deformations are more frequent at higher levels of sport climbing. These are accepted as unavoidable because it is assumed that, for optimal performance, a prerequisite is the wearing of a shoe, which is too tight and has an unnatural shape. Based on a biomechanical analysis, we came up with a different approach to shoe design. By using regional thinning of the sole, easy flexion and extension of the toes is made possible. The form of the shoe conforms to the natural form of the foot, the shoe closure provides a close fit for feet with width differences of up to 20 mm and a shoe-sizing system was developed. After testing prototypes, we conclude that the new shoe design can contribute to the prevention of foot injuries and deformations in sport climbing.