A mechanical model of muscle mechanics

The thesis describes the skeletal muscle contraction from a purely (micro)mechanical point of view. The fast time scale processes related to the power stroke event is firstly described as diffusion in a non-convex energy which leads to an overcoming of some drawbacks of the classical Huxley and Simmons model. The new model allows the description of the power stroke in the same framework of the Brownian ratchet theory, already used to describe the slower process of the attachment detachment of the myosin head from the actin sites. A global model is finally presented, able to reproduce not only the main features of the muscle contraction, but also to interpret the main phases of the whole cross bridge cycle. The efforts to maintain the modeling in the purely mechanical framework represent a first step to the possible construction of artificial machines based on skeletal muscle mechanics, more than a limitation on the physical interpretation of the chemical events