simtk.org

Hi there,

I would like to run a gait simulation (inverse dynamics) using OpenSim. However, I only have ASCII files of the kinematic data (marker coordinates or joint angles). Can I input those files to run a simulation?

Cheers,

Katja

Hi Katja!

Which marker set do you use? It's possible to run a kinematic simulation by cutting and pasting the data into the example files included with OpenSim or by exporting the data in .trc format, though you won't be able to generate forces I don't believe. You have to turn gravity off, so to speak, in the .osim file you wish to use, and you must modify a few of the xml files to reference the names of the markers you use if different from the examples. If you use Vicon's Plug-in-Gait, let me know and I can send a couple example files your way.

Hi Daniel,

Thanks for your quick response and the copy-paste suggestion!

Looking at the MOT files in the examples, I think it should be possible to copy paste my data into this file. However, is there any documentation which outlines angle convention and position/direction of the anatomical coordinate systems used within SIMM? Do the angle in MOT refer to clinical joint angles (Grood&Suntay) or to Euler angles?

Thanks heaps for your help!

Katja