Nonlinear stiffness--force relationships in whole mammalian skeletal muscles.

Small, sinusoidal length changes were superimposed on isometric contractions of fast- and slow-twitch mouse muscles, which were stimulated maximally via their nerves. Stiffness increased with increasing frequency of sinusoidal stimulation, but the relative time course of force and stiffness changes during twitch, tetanic, or partially fused contractions was quite invariant over a range of frequencies in both muscles. Typically, stiffness increases more rapidly than force during contraction and decreases less rapidly during relaxation. This pattern was observed at various temperatures and with various numbers of stimuli. It can be described by a nonlinear relation between stiffness and force with some hysteresis. The presence in the muscle of parallel and series elastic elements, whose stiffness varies with force, may account for the nonlinear relation. This nonlinearity can be used to relate the patterns for summation of force and stiffness observed with brief trains of stimuli under a variety of conditions.

[1]  M. Kawai,et al.  Differences in the transient response of fast and slow skeletal muscle fibers. Correlations between complex modulus and myosin light chains. , 1984, Biophysical journal.

[2]  D. Warshaw,et al.  Tension transients in single isolated smooth muscle cells. , 1983, Advances in experimental medicine and biology.

[3]  P Haugen,et al.  Short-range elasticity after tetanic stimulation in single muscle fibres of the frog. , 1982, Acta physiologica Scandinavica.

[4]  M. Kawai.  Correlation between exponential processes and cross-bridge kinetics. , 1982, Society of General Physiologists series.

[5]  D. Parry,et al.  Fiber type susceptibility in the dystrophic mouse , 1981, Experimental Neurology.

[6]  D. Stephenson,et al.  Calcium‐activated force responses in fast‐ and slow‐twitch skinned muscle fibres of the rat at different temperatures. , 1981, The Journal of physiology.

[7]  K. Ranatunga.  Influence of temperature on isometric tension development in mouse fast- and slow-twitch skeletal muscles , 1980, Experimental Neurology.

[8]  D. Brutsaert,et al.  Myocardial stiffness during hypoxic and reoxygenation contracture. , 1980, Cardiovascular research.

[9]  A. Huxley,et al.  Tension responses to sudden length change in stimulated frog muscle fibres near slack length , 1977, The Journal of physiology.

[10]  F. Zajac,et al.  The effect of activation history on tension production by individual muscle units , 1976, Brain Research.

[11]  V. Edgerton,et al.  HINDLIMB MUSCLE FIBER POPULATIONS OF FIVE MAMMALS , 1973 .

[12]  G. C. Joyce,et al.  The mechanical properties of cat soleus muscle during controlled lengthening and shortening movements , 1969, The Journal of physiology.

[13]  Constantine H. Houpis,et al.  Feedback Control System Analysis and Synthesis , 1966 .

[14]  H. Hartley.  The Modified Gauss-Newton Method for the Fitting of Non-Linear Regression Functions by Least Squares , 1961 .

[15]  R. Redheffer,et al.  Mathematics of Physics and Modern Engineering , 1958 .

[16]  A. Hill.  The heat of shortening and the dynamic constants of muscle , 1938 .