Christopher, I'm not trying to modify the c3d files themselves (which you can actually do in Mokka, but it's not scaleable for many trials); I'm trying to modify the files once imported as structures in MATLAB. That is what I currently do with my code, but I didn't know if it was possible to have a ...

Arash,

That's an interesting problem. How is your global coordinate system defined? Where is the origin?

If it's defined based on the treadmill and then you adjust the inclination of the treadmill, you might have an issue with the COP locations.

Best,
Maria

Benjamin, Thanks for the suggestion, but unfortunately that will not work for me. I need to do some processing to all the marker, force, and analog data. I was using the c3d2OpenSim toolbox with some custom functions to make these adjustments, but I want to update everything for OpenSim 4.0 now. It ...

Hi all, I'm trying to update my c3d conversion methods for OpenSim 4.0 using the provided osimC3D methods. I can import the osimC3D object and assign the markers and forces to structures for editing, but I need help with: 1) How to save edited marker/force structures back to the osimC3D object? 2) H...

Nicos, These are great points! I checked my kinematic data, and as far as I can tell, the filtering has very little effect because they are already pretty clean. I do not think the kinematic data are causing the problem. I checked the GRF data with IK results. The GRF vector is placed well under the...

Mike,

Thanks for your suggestions! Both walking and running data are on an instrumented treadmill (no incline). Kinematics get filtered at 8Hz.

My COP data are definitely noisy as well. I will try some different filtering techniques for my COP and moment data and see if that helps anything!

Maria

Does anyone have suggestions for how to deal with noisy treadmill force data (specifically X/Z noise)? During walking they look okay but they are considerably noisier during running. I am currently using a 4th order Butterworth filter with cutoff of 10Hz to filter all of my force data, which works w...

Ayman, Thanks for the quick reply. I don't think there are any issues with permissions. In part 2 of scaling, it is able to write the output scale file (Sub_ScaleSet_Applied.xml) to the same directory with no issues. I have checked the paths in each part of the scale file and they appear to be okay ...

Hello, I seem to be having the same issue. I've tried scaling with both the Rajagopal 2016 and Lai 2017 full body models in OpenSim 3.3 and 4.0. The exact same scaling setup works in 3.3 but gets stuck placing markers on model in "executing scaling..." with 4.0. There are no obvious errors during st...

James, Thanks, this is helpful! I wanted to call the IKTastSet and MeasurementSet files because I have generic ones defined that I wanted to use for batch processing: <MeasurementSet file=".\Scale_MeasurementSet.xml"/> This is where the file generated during batch processing "loses" the file I defin...