Nonlinearities make a difference: comparison of two common Hill-type models with real muscle

摘要: Compared to complex structural Huxley-type models, Hill-type models phenomenologically describe muscle contraction using only few state variables. The dominate in the ever expanding field of musculoskeletal simulations for simplicity and low computational cost. Reasonable parameters are required gain insight into mechanics movement. two most common used contain three components. series elastic component is connected contractile component. A parallel either both (model [CC+SEC]), or with [CC]). As soon as at least one components exhibits substantial nonlinearities, as, e.g., by ability turn on off, mechanically different. We tested which model ([CC+SEC] [CC]) represents cat soleus better. Ramp experiments consisting an isometric isokinetic part were performed situ preparation supramaximal nerve stimulation. containing force–length force–velocity relationship, excitation–contraction coupling force–elongation relations fitted data. To test might represent better, obtained compared experimentally determined parameters. Determined situations negligible passive force, relation independent chosen model. In contrast [CC+SEC], these predicted [CC] accordance experimental relations. conclusion seemed better dynamics should be preferred nonlinear regression modeling.