Chronic inflammations of the distal Achilles tendon correspond frequently to a mechanical irritation of the subcalcaneal bursa. On grounds of the biomechanical analysis an excessive inward bending of the hindfoot is postulated as the reason. So a conception for the clinical therapy is detected. The first measure will be a statics correction of the foot and a local application of antalgics. In case of unsuccessfulness after 3 months the surgical resection of the calcaneus exostosis is performed. After 3 months of conservative treatment 15 of 24 athletic patients are free of pain. The other 9 patients are free of pain 3 months after the surgical treatment. In either case all patients return to their former sports activity 6 months after the beginning of the treatment.