[Thermoanalytic studies of bundles of collagen fibers with biomechanical methods]

Thermomechanical experiments were performed on collagenous fibre bundles of tendons from cattle and man. Subsequent to extensions of fibre bundles the particular amount of length was kept constant (isometric conditions). At the end of the relaxation under approximative equilibrium conditions (mechanical steady state phase) the temperature was raised proportional to time (with linear temperature rate). In the range between 0 and 43 degrees Celsius the isometric force decreased in form of an approximately straight line. This line was declined at 43 degrees C (thermal depression region). After the thermal shrinkage region (62-64 degrees C) the isometric force increased considerably. In this ascending part of the isometric thermal mechanogram 2 domains of slope can be observed. They are designed as lower and upper thermal transition region. In the ascending part of the isometric thermal mechanogram an isothermal relaxation is to be seen under constant temperature conditions. The isothermal isorheological line and isothermal superelevation are described. The results are discussed in context with their meaning for functional anatomy, muscle physiology, supercoolings, and burnings.