Fig. 7

Simulation of a series of isotonic afterloaded contractions in the TP + M model. The initial virtual sample length L_init is equal to 90%L_max. F_isom is a peak active isometric force at L_init. Each afterload was applied following a steady-state isometric contraction (dotted lines) varying from a high afterload of 0.9F_isom (black lines) to a low afterload of 0.1F_isom (light grey lines). a Time-dependent signals of the generated force (F/F_isom), sample length, sarcomere length and membrane potential for various loads applied. b Time-dependent signals of the concentration of calcium–troponin C complexes ([Ca–TnC]), intracellular Ca²⁺ transient ([Ca²⁺]_i), Na⁺–Ca²⁺ exchange current (i_NaCa) and inward rectifier K⁺ current (i_K1) for isometric and afterloaded contractions at low afterload