Fig. 30. Diagram showing the dependence of muscle tension on filament overlap. Tension progressively increases with filament overlap until all possible crossbridges have formed. The tension plateaus until the thin filaments begin to slide past each other, producing some reduction in tension. The tension drops rapidly as the thin filaments overlap into the crossbridge-forming portion of the thick filament and presumably interfere with crossbridge formation. (Modified from Gordon AM, Huxley AF, Julian FJ: The variation in isometric tension with sarcomere length in vertebrate muscle fibers. J Physiol (Lond) 184:170, 1966.)