Meeting Abstract

P1.123  Sunday, Jan. 4  An improved model of vertebrate muscle force generation BROCIA, S.; DING, Z.*; ROOT, R.G.; Lafayette College; Lafayette College; Lafayette College dingz@lafayette.edu

Mathematical models of the generation of force in muscles by way of crossbridges date back to work by Huxley in the 1950s. The Huxley Model is based on a two-state model for crossbridges; a crossbridge is either attached to an actin filament or detached. This approach is inadequate to describe the conversion of chemical to mechanical energy by crossbridges. More recent models, like that of Tanner et al. (2007), offer more realism in the conversion of energy at the expense of computational complexity. We offer a three-state model that is more up-to-date than Huxley, but simpler than Tanner, and apply it to the study of swimming fish. This model includes pre-powerstroke and post-powerstroke states of attachment. Using it, we analyzed the tension generated and change in length of a myofibril over time under fixed loading. The model demonstrates the transition to constant velocity shortening predicted by Hill’s law with transient behavior similar to that observed by Jewell & Wilkie (1958). This suggests that the model captures fundamental features of muscle physiology, and serves as a useful baseline for further investigations.