Before revision:  Here, we extend a simple myosin II cross-bridge model to consider an ensemble of myosin motors engaging a single actin filament with an elastic tether. Consistent with previous work, we find that the duration of actin engagement and average force are highly sensitive to changes in ensemble size(Nheads) , motor duty ratio (dr), and environmental stiffness(k).
After revision:  Here, we extend a simple myosin II cross-bridge model . Similar actin gliding speeds and force-velocity curves expected from previous experiments were observed. Motor force output on an elastic load was regulated by two timescales--that of their attachment to F-actin, which varied sharply with the ensemble size , motor duty ratio (dr), and environmental stiffness(k).