simtk.org

Hi all,

I have just met Opensim and I am trying to learn it.
I encountered a problem and kindly would like you to advise me.

As far as I know, the constructed musculoskeletal models in Opensim library belong to just human body; however I would like to model and simulate a cat hindlimb's musculoskeletal system in Opensim. In order to achieve this first, I plan to integrate anthropometric parameters of cat muscles to the program by means of Notepad++ program. But, I do not have the geometry file with .vtp extension belonging to the cat skeletal system. I think, for the human body modeling, the .vtp files are loaded automatically to the Opensim while the program is being run and these files make the skeletal system visible in the Opensim.

I wonder if it is possible to model and visualize an animal musculoskeletal system in Opensim instead of the one of human body. If so, which way should I follow? If there is a drawing program ( or another assistant program ) that is necessary to do this, I want to learn it. I expect your suggestions about this issue.

Thank you very much for your suggestions in advance.

Best regards,
Derya

Hi Derya,

You will likely need to use a number of different programs to create your cat model. I've recently created a sheep hindlimb model from scratch and am now in the process of refining and validating my work. To create my bone geometry files I used a program called Amira to convert a CT scan of the sheep hindlimb to a 3D Mesh. This is a well established process, but time consuming. From there, I used SIMM to define joint coordinates and muscles O/I points (Recent advancements in OpenSim 3.0-3.1 allow you to do this in OpenSim as well). The muscle paths were determined through a combination of detailed dissection, anatomy texts, and, for the most "critical" muscles, moment arm experiments.

Let me know if you have any specific questions. I'll be releasing my sheep model to the OpenSim community once validated.

Cheers,

Zach

Dear Zach,

Thank you for your reply. I will try to make up my model with the help of your answer and Amira that you use as an assistant programme.
If I have any problem or question during this process, I will expect your help. Thank you very much in advance.

Best regards,
Derya