Search found 88 matches

by Jacob J. Banks
Thu May 23, 2024 10:09 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

I'm not the one to ask (Brett Allaire does most of that for the Anderson group), but that sounds right.
I've attached a picture of how/when the process was explained to me. Hopefully this helps, otherwise I could give you Brett's contact info.
Jake Banks
by Jacob J. Banks
Thu May 16, 2024 6:33 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Tue Apr 09, 2024 5:48 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

Good deal. Glad to hear it.
Let me know if there is anything else.
Jake Banks
by Jacob J. Banks
Mon Apr 08, 2024 8:53 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Fri Mar 29, 2024 6:26 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Thu Mar 28, 2024 12:50 pm
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Wed Mar 27, 2024 6:00 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Tue Mar 26, 2024 7:53 am
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Thu Mar 21, 2024 2:21 pm
Forum: Spine and rib cage model in OpenSim
Topic: subject-specific implementation of pelvic alignment
Replies: 18
Views: 3008

Re: subject-specific implementation of pelvic alignment

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...
by Jacob J. Banks
Tue Feb 27, 2024 8:32 am
Forum: Spine and rib cage model in OpenSim
Topic: Joint reaction analysis
Replies: 2
Views: 430

Re: Joint reaction analysis

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....