Reports

Muscular contraction: kinetics of crossbridge attachment studied by high-frequency stiffness measurements

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Science  02 Jul 1982:
Vol. 217, Issue 4554, pp. 70-72
DOI: 10.1126/science.6979780

Abstract

Instantaneous stiffness of frog skeletal muscle, an indication of the proportion of attached crossbridges, was determined drug the tetanus rise and after a step length change imposed during the tetanus plateau. During the onset of contraction as well as after a step, the ratio of stiffness to force differed from that determined during the tetanus plateau. The data after a step are predicted by the Huxley-Simmons model of muscular contraction, but the results during the rise suggest that a long-lived state may exist between crossbridge attachment and force generation.