I would suggest looking at the sample code I provided Riza (a few messages above). That should give you the methods to adjust bodies/joints manually via an API. You need to use OpenSim specific syntax when calling things. Otherwise, try manually adjusting things via a text editor to get a feel for t...

Good deal. Glad to hear it.
Let me know if there is anything else.
Jake Banks

Riza, See if this does what you want... I think it may. Admittedly, I was/am a little rusty with API coding. My current role doesn't require much of it. So, it was fun to piece together old code and be reminded of what I once 2nd nature for me. I recommend using the model I attached in this folder f...

I'm slowly getting there... I think what you suggested does ~95% of what you want it to. However, as you pointed out in an earlier correspondence, the Sacrum rotates about a point distal to the top center from which you reference your angles (see pic). I can't recall 100% why this is, but it is. You...

Did your 'work around' work? I'm admittedly a little confused (still). It seems to me like things are working. The angles/inputs may just not be how things are defined clinically, so you may need to adjust them to match how the model works. Otherwise, it is just a geometry problem. Sorry, for my lac...

Sorry for the delay, I had meetings in the afternoon (yesterday). Hmmmmm.... at the risk of pointing out the obvious, 6.13 + 3.87 = 10. So it appears to be a compensation for the SS to put the feet flat on the ground. Why the adjustment is proportioned that way, I do not know. So, is this when you a...

Thanks again for the kind words. Are you sure that changing the Sacrum_offset z orientation changes those 3 angles? It shouldn't impact anything in the x or y. I just modified a model (by editing the .osim file by hand) the way you are and I don't see PT/PI changes. As for motion files, yes changing...

You're welcome, your kind words are appreciated. As for implementing participant-specific pelvic information... do you not produce the desired result using just the scaling tool? Or are you creating these models without a markerset? If you're creating/scaling without a markerset, you can just manual...

https://simtk-confluence.stanford.edu:8443/display/OpenSim/Joint+Reactions+Analysis I can't explain it any better than the OpenSim documentation. But in general, it appears that you have the correct idea. The JRA considers all the forces (when solved for) and then finds the one unknown of the joint....

We divide by 2 because we are estimating the vertebral and not the joint load. So, we take the average of the superior and inferior joint forces to estimate the vertebral force (what is between the 2 joints).
Jake Banks