Fig. 8
a Axial stiffness analysis of single myofibrils suspended between glass needles. Upper panel length changes applied to one end of a preparation, and lower panel force responses of the other end of the preparation, in which brief traces are shown for clarity for a relaxed, b contracting, and c rigor states. See details in the text. b Relationship between the axial Young’s modulus of single myofibrils and the radial Young’s modulus of the soft components of the A-band region of single myofibrils in various physiological states. Relaxed (opened circle), a low ionic-strength state (80 mM) (open inverted triangle), (+)AMPPNP (filled diamond), contracting (opened triangle), and rigor (filled circle)