How can I apply a torque actuator (say T = k*coordinate) without writing a plugin? The C++ code is really complicated and the plugin examples are difficult to follow. Any help would be appreciated. There was another post on this that said OpenSim 2.0 might have this capability.

<t>I have run a body kinematics analysis. However, I'm not sure how to interpret the angles given. The header says it gives body fixed Euler X-Y-Z angles. Is this for a 1-2-3 sequence rotation? If I want to get the proper rotation matrix for each body from the ground, what sequence should I use? Usu...

I am trying to do CMC with a patellar ligament in place. It is modeled as a muscle, but I'm not sure how to tell CMC to not use it to move the model. Any suggestions?

You're right! I think the patella has 0 mass. I'll double check that.

I have a simple right leg model with 3 muscles (bothlegs.osim simplified). I have a .mot file specifying degrees of freedom that I can get to move the model. However, when I try to do Inverse Dynamics I can't get it to run. Any ideas why? Do I have to have external forces?

<t>I have a .mot file to specify the motion of my model (right leg with 3 muscles and a patella, the only dof is knee flexion angle, all hip and angle angles/translations set to 0). I have a kinematic knee and patella that translate and rotate depend on knee flexion angle (like BothLegs.osim). Is th...

Your muscle excitation is 0 because inverse dynamics only computes joint forces and moments. You need to run CMC to get muscle excitations.

Hi Tim, I believe femur_r_Y is the Y coordinate of the femur's center of mass (in the global coordinate system) and femur_r_Oy is the orientation of the femur's Y axis with respect to the global coordinate system using a fixed body sequence of rotations.

Anne

No response for a plugin yet. I have some self written Matlab code that I may try to implement this semester.

Ahh..that is what I need. However, when tracking the line of action of muscles, sometimes via points turn on and off. My code looks at the general coordinates and calculate whether the via point is used or not.