FIGURE 4.

Descriptive parameters measured from experimental and simulated records. Symbols show mean ± SD for the (A) relative tension, P_ss/P₀, (B) relative overshoot, P_max/P_ss, (C) rate of tension recovery, k_tr, and (D) crossing time, t_ct, parameters for individual pCa values ranging from 6.5 to 4.5. Experimental values (triangles) are replotted from Fig. 4 of Campbell (3). Simulated values computed with (φ₀/κ_m = φ₀/κ_a = 0.0645 nm (circles) (see Table 1)) and without (φ₀/κ_m = φ₀/κ_a = 6.45 × 10⁻⁸ nm (squares)) filament compliance were calculated as described for Fig. 2. The simulated data sets include points corresponding to pCa 6.4 activations. Equivalent experimental records were not available. pCa₅₀ values (indicative of the calcium concentration required to produce half-maximal force) differed by <0.01 for the data sets simulated with and without filament compliance.