Fig. 2.

Muscle thixotropy. Isolated, relaxed extensor brevis profundus digiti IV muscle (frog) was stretched by 50 µm. The first stretch encountered an initial resistance to stretch [the short-range elastic component (SREC)]. When a second stretch was immediately applied, the initial resistance was greatly reduced. The slope of the line (right panel) is the stiffness. The stiffness of the SREC is less in the second (and all subsequent) stretches unless time is allowed between stretches. The initial resistance is regained only by waiting for a few seconds between stretches. [Redrawn from Herbst (31) with permission from Springer Nature. Copyright 1976 Springer-Verlag.]