Figure A. 10.

Conceptual explanation of FLAR rightward shift with decreasing [Ca²⁺]. Some changes (rightward translocation, column A; squaring, column C) in the myosin force generation curve (${\tilde{F}}_{\text{asc}}$, top row) result in rightward shifts of the FLAR peak (middle row). Changing ${\tilde{F}}_{\text{asc}}$ slope, alternatively, does not (column B). An understanding of these different responses of the FLAR peak to changes in ${\tilde{F}}_{\text{asc}}$ can be obtained by considering how these changes affect the equation that gives rise to the FLAR, $\tilde{F}\left({\ell }_{\text{hs}}\right)={\tilde{F}}_{\text{asc}}\cdot {\tilde{F}}_{\text{des}}$ (bottom row). See text for detailed explanation. Keys in (A2) and (A3) apply to all other panels in same row. To see this figure in color, go online.