Millard Muscle as passive element

[Michele Baldoni]

Hi,

I am trying to use the Millard equilibrium muscle as a passive element, in order to represent a ligament. I modified various parameters in the muscle curves but was never able to obtain a suitable behavior, I have too much difference between the force developed in a static pose and the force developed during a motion to reach that static pose. The final values are not coincident.
Is there any way to obtain a passive or quasi-passive element using the Millard Equilibrium muscle? What parameters shall I change?
And if it is not possible is there any other way to simulate a ligament behavior with a muscle?

Thank you,

Michele

[jimmy d]

Hi Michele,

You could use an OpenSim ligament or a perhaps a PathSpring.

Cheers,
-James

[Michele Baldoni]

Hi James,

thank you, but I am trying to use an actuator, because with ligaments or pathsprings I have problems in obtaining reasonable results when performing the Joint Reaction Analysis.

Best,

Michele