Musculoskeletal disorders (MSD) are among the main causes of pain and disability in adults. Tendon disorders are an important part of MSD. Among them, the rupture of the Achilles tendon is the most common, with a prevalence of about 18 to 100000. The disorder mostly affects men between 30 and 50 years. Up today, the mechanical and elastic properties of the Achilles tendon are still unknown, and that both in healthy subjects in pathology. The viscoelastic properties or dynamic mechanical properties are directly related to the tendon of the health status and its elongation capacity. Additional tests that we have to explore the Achilles tendon are ultrasound and MRI. They bring mainly morphological information but can not demonstrate the mechanical properties of the tendon.~For this purpose, the laboratory UMR Inserm U930 - CNRS ERL 3106 in Tours has developed a non-invasive ultrasonic device, named Achillus, which, via an ultrasonic probe, allowing to access the viscoelastic properties of the tendon during the contraction of the sural triceps. It is therefore important in the exploratory work we propose to have a proven method of calibration of forces applied to the tendon, which is why an ergometer laboratory biomechanics and bioengineering at UT Compiègne is associated with our experiments.~No human study has yet been conducted to evaluate this method in medically relevant situations such as hyper solicitation and incorporated rupture.~This is what we want to do in this first protocol: in vivo observation of the normal values and variations, looking for changes related to hyper solicitation and finally trying to highlight a tendon fragility parameter for patients who have experienced of a Achilles tendon rupture.
Among Musculoskeletal disorders (MSD) the rupture of the Achilles tendon is the most common. Up today, the mechanical and elastic properties of the Achilles tendon are still unknown, and that both in healthy subjects in pathology. The viscoelastic properties or dynamic mechanical properties are directly related to the tendon of the health status and its elongation capacity.~The laboratory UMR Inserm U930 - CNRS ERL 3106 in Tours has developed a non-invasive ultrasonic device, named Achillus, which, via an ultrasonic probe, allowing to access the viscoelastic properties of the tendon during the contraction of the sural triceps.~This is what we want to do in this first protocol: in vivo observation of the normal values and variations, looking for changes related to hyper solicitation and finally trying to highlight a tendon fragility parameter for patients who have experienced of a Achilles tendon rupture.