I’m trying to understand how ContactSurfaceLin.any works. But I don’t know what is AnyMuscleModelUsr1! It gets F0 and S as input, but I think It should get F0 only. because the cost function is a function of f/f0 (Damsgaard 2006). so what is S(strength)?



AnyMuscleModelUsr1 is a special muscle model where you can input a variable strength. This is the S member. It replaces F0 (constant strength) and you can use any kind of expresion in it to make it varible, for example it can depend on a kinematic measure.

Best regards, Sylvain.

thanks for your reply.
can it get non zero S and F0 instantaneously? Does it represent a spring when f0=0 and S is not zero? what is the difference between S and F0? can you refer me to a reference?


there is a short description of the user defined muscle in the Wiki: