Muscle Velocity of contraction

[Joana Alves]

Hi there!
I'm getting started with OpenSim platform. I hope it will help me do my PhD in Biomedical Engineering.
I'm using this tool to study the msucle and get some good data. I need the velocity of contraction (or actuation) of the lower limb muscles, mostly gastrocnemius. Besides the velocity I need the muscle length. I know how to get the length plotted, but is it possible to analyze the velocity?

Thanks in advance!

[Dimitar Stanev]

You can use the AnalyzeTool and MuscleAnalysis for an arbitrary movement:

https://simtk-confluence.stanford.edu/d ... lysis+Tool

The contraction velocity is one of the outputs of this analysis.

[Joana Alves]

Hi Dimitar
Thanks for your reply.

I am really new at using OpenSim so I am not understanding quite well what I should do. I followed the link you sent me but I couldn't run the analysis as you can see on the image.

I could run an analysis with Input Control as subject01_walk1_grf.xml and 3DGaitModel2354_MuscleAnalysis_FiberVelocity.sto as state. However, in the plot, fiber velocity was not there as an output parameter. I suppose I should choose MuscleAnalysis_FiberVelocity as a state, but what should I put as input?

There are some figures in the attachment.
Thanks in advance.

[Dimitar Stanev]

I could run an analysis with Input Control as subject01_walk1_grf.xml and

This file contains the setup for the ground reaction forces and is not a control input. You must provide the motion file (motion from file) that you obtained from inverse kinematics and to apply the GRF on the second tab (Actuators and External Loads).

Please read the user guide carefully starting with the basics. It will save you time!

Regards