Isometric twitch simulations. (A) An example of the input calcium trace (blue dashed line) and the resulting single simulated twitch force (black) using baseline model conditions. (B) An average (black) of 100 simulations (gray) for the baseline simulated conditions, demonstrating the stochastic nature of the model. (C) Average twitch trace of 100 independent simulations of control and each of our modifications indicated in the legend. (D) Average control twitch subtracted from average twitch of each of our modifications reveals both magnitude and shape changes.