Table 1.

Parameters for active stress calculation with 2-state model.

Parameter	Definition	Value	Unit
ρ	Number of myosin heads in a hypothetical half-sarcomere with a cross-sectional area of 1 m2	6.9 × 1016	m−2
kcb	Stiffness of the cross-bridges	0.001	N/m
xps	Cross-bridge length when a myosin head is bound to a directly opposed binding site	5	nm
aon	Rate constant	DO*	s−1nM−1
aoff	Rate constant	DO*	s−1
kplus	Constant defining positive cooperative effects	DO*	s−1
kminus	Constant defining negative cooperative effects	DO*	s−1
k1 (xi)	Attachment rate constant	$C_k{e}^{\frac{-k_{cb}{x_i}^2}{2BT}}$ (DO*)	s−1nm−1
k−1 (xi)	Detachment rate constant	$k_d+k_{db}{x_i}^4$ (DO*)	s−1

x_i, cross-bridge length as defined in Figure 3 in nm. B, Boltzmann constant (1.381 × 10^{- 23} JK^{- 1}). T, the experimental temperature (288 K).

DO^*, Determined by optimization.