A novel three-filament model of force generation in eccentric contraction of skeletal muscles.

We propose and examine Mug a three filament model of skeletal muscle force generation, thereby extending classical cross-bridge models by involving titin-actin interaction upon active force production.In regions with optimal actin-myosin overlap, the model does not alter energy and force predictions of cross-bridge models for isometric contractions.However, in contrast to cross-bridge models, the three filament model accurately predicts history-dependent force generation in Girls Bag half sarcomeres for eccentric and concentric contractions, and predicts the activation-dependent forces for stretches beyond actin-myosin filament overlap.