simulating handicapped upper-limbs

[Lukas Kammler]

Dear Readers,

As part of a research project, I aim to simulate seated individuals with physical disabilities. My focus is primarily on impairments that restrict the range of motion and mobility of the arms.

I am relatively new to this field and have only been using OpenSim 4.5 for a week, so please excuse me if some of my following questions seem obvious or trivial:
1. Are there already full-body models of seated individuals in OpenSim? If not, would it be a feasible solution to simply angle the joints of the lower extremities of a standing model so that it ends up in a sitting position?
2. I intended to represent the restrictions caused by the disabilities by simply imposing stronger limitations on the possible joint angles of the upper extremities. Is such an intervention "best practice"? Are there other mechanisms that I am overlooking?
3. If the approach described in 1. & 2. is feasible, can I then simply load motion files for generic arm movements into this model? Or would this lead to crashes or undefined behavior due to the manual restriction of joint angles? Do such generic grasping movements already exist as motion files?
4. I initially considered using the Moco Plugin; however, it seems somewhat overkill for my application, as the focus is solely on grasping movements and associated reach, and the simulation of the movement itself. Are there any plugins that I may not be aware of that could be useful for my application?

Thank you in advance for reading and for any helpful responses.

Best regards
Lukas Kammler