I am interested in adding stiffness properties to joints, i.e. how much force to apply to a joint in order to move it a certain distance. Is there a way to set this up in the osim file?

Yes, I have tried it with that model and also with the neck model. I guess I'm just not understanding how or when to use them correctly. Besides the user guide is there anywhere that offers a more in depth explanation into coupler constraints?

<t>I have made a model both with and without kinematic coordinate coupler constraints and have made a motion file for both which puts them through the same motion. When using the static optimization and CMC tools I get very different results for both models for the exact same motions. It seems that ...

I'm trying to get a CMC simulation working and I have noticed that even when my joint ranges are clamped, they still move outside their defined limits. Is this normal, and if so is there a way to stop it from happening?

Is it at all possible to use OpenSim to calculate the ground reaction force acting on a model while walking?

Thanks Tim!

When using the CMC tool I get a warning for some muscles, e.g. "WARN - small force range for muscleX ( A to B )"

What exactly are numbers A and B and what muscle parameters do I need to be addressing to change this?

Thanks,

Moe

In Static optimization, what exactly do performance and constraint violation relate to and how are they calculated?

Thanks!

Moe

<t>Hi Ayman,<br/> <br/> It does finish computing initial states. It then says:<br/> <br/> "Using CMC to track the specified kinematics<br/> Integrating from 0.03 to 1"<br/> <br/> But only executes for 0.03 and then prints results. If I start at another time e.g. 0.5, it will only go as far as 0.53 e...

<t>I have just started using the CMC tool on a model and as it runs, in the message window I am getting "RKF.step: NAN in state 1 at time 0" repeatedly. The CMC execution doesn't finish, but I don't get an error message either. Would there be something obvious wrong with my model or motion file that...