To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S7. Preactivation of five sarcomeres within a myofibril before full activation. Two contractions of a myofibril along its entire length followed by the preactivation of five sarcomeres before full contraction. Movie was accelerated by 5×. Microfluidic perfusion shows intersarcomere dynamics within single skeletal muscle myofibrils Felipe de Souza Leite, Fabio C. Minozzo, David Altman, and Dilson E. Rassier PNAS. 2017. 114:8794-8799 DOI: 10.1073/pnas.1700615114 Download Original Video Browse All Videos »