Fig 8.

Top: Total, active, and passive force—length relations. Superimposed on the total stress curve are, for a muscle length of L/L₀ = 1.5, the half-sarcomere lengths predicted by models ${\text{M}}_{\text{x}}^{\text{x}}$ and M^Fv (red crosses), and models M_ATI and ${\text{M}}_{\text{ATI}}^{\text{Fv}}$ (blue dot). The value predicted by models M_ATI and ${\text{M}}_{\text{ATI}}^{\text{Fv}}$ coincides with the theoretically predicted stress—stretch value. Bottom: Histogram of half-sarcomere lengths in models ${\text{M}}_{\text{x}}^{\text{x}}$ and M^Fv (red), and models M_ATI and ${\text{M}}_{\text{ATI}}^{\text{Fv}}$(blue, scaled for readability). Under conditions of steady state (after 2.5 s), the results of models ${\text{M}}_{\text{x}}^{\text{x}}$ and M^Fv, as well as those of models M_ATI and ${\text{M}}_{\text{ATI}}^{\text{Fv}}$, coincide.