Separation of active and passive components of short-range stiffness of muscle.

The short-range stiffness of smoothly but submaximally contracting isometric soleus muscles of anesthetised cats was measured by applying small fast stretches. The ratio of isometric tension to stiffness was plotted against tension over a wide range of muscle lengths and stimulus rates. The results fitted a straight line well, as predicted from crossbridge theory, showing the stiffness to be a function of tension only, independent of the combination of length and stimulus rate used to generate the tension. The major deviation from this line was attributed to incomplete fusion at low frequencies of stimulation. Values believed to be tendon compliance and crossbridge tension per unit of stiffness were found from the graph, and the tendon compliance correlated with the maximum muscle tension. Shortening the tendon by attaching nearer to the muscle changed the results in a manner consistent with the theory, provided that appropriate precautions were taken against slippage.

[1]  A. Hill.  The abrupt transition from rest to activity in muscle , 1949, Proceedings of the Royal Society of London. Series B - Biological Sciences.

[2]  A V HILL.  The series elastic component of muscle. , 1950, Proceedings of the Royal Society of London. Series B, Biological sciences.

[3]  D. Wilkie.  Measurement of the series elastic component at various times during a single muscle twitch , 1956, The Journal of physiology.

[4]  A. Huxley.  Muscle structure and theories of contraction. , 1957, Progress in biophysics and biophysical chemistry.

[5]  R. Close.  Dynamic properties of fast and slow skeletal muscles of the rat during development , 1964, The Journal of physiology.

[6]  J. Wells,et al.  Comparison of mechanical properties between slow and fast mammalian muscles , 1965, The Journal of physiology.

[7]  H E Huxley,et al.  The Mechanism of Muscular Contraction , 1965, Scientific American.

[8]  D. K. Hill,et al.  Tension due to interaction between the sliding filaments in resting striated muscle. the effect of stimulation , 1968, The Journal of physiology.

[9]  P. Rack,et al.  The effects of length and stimulus rate on tension in the isometric cat soleus muscle , 1969, The Journal of physiology.

[10]  R. J. Podolsky,et al.  Cross-bridge properties derived from muscle isotonic velocity transients. , 1969, Proceedings of the National Academy of Sciences of the United States of America.

[11]  G. C. Joyce,et al.  Isotonic lengthening and shortening movements of cat soleus muscle , 1969, The Journal of physiology.

[12]  A. Huxley,et al.  Mechanical Transients and the Origin of Muscular Force , 1973 .

[13]  P. Rack,et al.  The short range stiffness of active mammalian muscle. , 1973, The Journal of physiology.

[14]  F. Julian,et al.  A model for the transient and steady-state mechanical behavior of contracting muscle. , 1974, Biophysical journal.