Illustrated by the example of Achilles tendon injuries dissertation

introduction Long distance runners often experience chronic overuse injuries and Achilles tendon injuries are known to be one of the most common physical complaints within this group. However, while several injury inducing factors were discussed in the literature, no clear proof of cause and effect could be settled. Excessive foot motion in the frontal plane and increased running speed are frequently contemplated as injury inducing factors in runners. Motion control shoes aim at limiting immoderate pronation and supination. During running repeated impacts are transferred in the axial direction along the lower leg, therefore possibly affecting the oscillation behavior of the Achilles tendon. Also, variations in neuromuscular control may lead to increased stresses and loadings at the Achilles tendon. Until now, no simultaneous measurements of plantar pressure as an impact load, muscle activity as a modulating system, foot kinematics as a load distributor and oscillations at the Achilles tendon as a loading case were performed in runners. The purpose of the thesis at hand was the development and implementation of a complex measurement system to assess parameter constellations, which may be associated with overuse injuries at the Achilles tendon in runners and which allow the differentiation between runners with Achilles tendon complaints and their healthy counterparts. methods A series of measurements consisting of four separate studies was performed. Biomechanical parameters from plantar pressure, muscle activity, foot kinematics and oscillations at the Achilles tendon were evaluated while several external factors were varied. During the first two studies, the effects of different footwear modifications, variations in running speed and in ground condi-