The long-term objective of this training proposal is to gain an understanding of the basic physiological mechanisms contributing to the force generating properties of muscle, specifically for heterogeneous single muscle fibers. To this end, the goal of Specific Aim 1 is to determine the parameters of a cross-bridge model, the Distributed Moment (DM) muscle model, for each of the four fiber types. An identification procedure will use the experimentally obtained mechanical measures in single type-identified fibers including force-velocity, stiffness, and yielding properties at various levels of activation. These muscle models will be used in Specific Aim 2 to understand which factors and mechanisms represented in the model are important during physiologically realistic mechanical conditions. Specifically, the effects of movement history on stiffness and yielding properties will be studied. Moreover, the model will be validated by the accurate prediction of the mechanical response under those conditions. The clinical significance of this proposal is that the documented biochemical fiber type alterations (muscle plasticity), which occur in the pathology of muscle, can be used in conjunction with fiber type based cross-bridge models to predict changes in muscle force generating properties.
| Lin, David C; Nichols, T Richard (2003) Parameter estimation in a crossbridge muscle model. J Biomech Eng 125:132-40 |
