Single-leg landings - Muscle Activations (static optimization)

[Ana Azevedo]

Hello all,

I am currently using OpenSim 3.3 to investigate the lower extremity biomechanics in single-leg landings.
We are using the model gait2392 with our marker set. We have kinematics and external loads data only of the right side (we had no markers on the left side). At this stage we already computed the joint angles and joint moments (IK and ID).

Now we want to estimate muscles activations and joint reaction forces. Thus, 2 questions arises:
1. I have been following the OpenSim tutorials to run static optimization and joint reaction forces (https://www.youtube.com/watch?v=ly4rhOOifO0) and I cannot find how to get the Actuators file to use for static optimization (Actuators and External Loads). It seems that we need to run the CMC to get that file. But I am still in the Static Optimization step. How can I get it?
2. In the static optimization tool how can I deal with the left side, since our task is a single-leg landing? Is there a place to set no calculations for the left side? Or is there any other way to get my outputs (muscle activations and forces) only for the right side?

Looking forward for your reply.
Thank you in advance.

Best regards,
Ana Azevedo

[Dimitar Stanev]

1. You can find an example file of reserve actuators for this model in the folder that ships with OpenSim. You can adapt this file for your needs by removing or adding reserve actuators to the model.

https://github.com/opensim-org/opensim- ... 92_Simbody

2. You can remove the left leg of the model from the .osim file.

[Ana Azevedo]

Thank you,

Ana