simtk.org

Hi all,

I find that there is a constraint of minimum activation for Thelen2013 muscle.
OPENSIM_THROW_IF_FRMOBJ(get_minimum_activation() < 0.01,
InvalidPropertyValue, getProperty_minimum_activation().getName(),
"Minimum activation cannot be less than 0.01");

Why has it been added to Thelen2013 muscle? Why the value is 0.01?
Why other muscle types (e.g. Millard2012EquilibriumMuscle) do not have such constraint?

Thank you in advance,
Jiang

Details about the modeling choices for the Thelen2013 muscle can be found here. The choice of default values, like minimum activation, were choosen to reduce numerical singularities.