At what point does a model transition from a "toy model" to a realistic one whose results can be regarded as a reasonably realistic? To me three flexors and three extensors seem sufficient for elbow flexion control, but I appreciate that shoulder flexion/extension muscles are underrepresented. How c...

Hi James, Thank you very much for your answers. Your explanations make sense, but I'm still having difficulty understanding these static optimization results... I've done what you suggested in the figure below: (a) extracted the moment arms for each muscle, (b) computed muscle moments, (c) computed ...

That sounds plausible, but if that were true why do the extensor forces return to zero at about 150 deg flexion as depicted in the figure below? Shouldn't there be greater passive extensor force at 150 deg than at 90 deg?

Hello, I'm trying to understand static optimization results for the arm26 model for different elbow angles. The results are depicted in the figure below. static-optimization.png These extensor results are not what I was expecting. I understand that the solution depends on the muscles' force-length r...

Hi Chris, thanks so much for your fast reply! I've now got everything working, but I'll follow up with details just in case anyone else is new to cmake like me. First, you're correct, the actual compiler I was using was clang. I tried to write my own compiler command because I've used gcc and g++ to...

Hi, I've been able to successfully build and install simbody on Mac 10.11, and I'm able to successfully run the examples: cd /usr/local/SimTK/share/doc/simbody/examples/bin ./SimbodyInstallTest ./ExamplePendulum I'm now trying to compile and run ExamplePendulum.cpp using g++ as follows: g++ ExampleP...

Great, thanks for that Ahmet.
And thanks again for sharing this fabulous resource with the community!
Todd

Understood, thanks for clarifying.

Just curious: is that flexed-posture loading meant to relate to a particular in vitro loading experiment or a particular in vivo task?

Hi Ahmet, I have a question about the boundary conditions as implemented in Version 2 of the Generation 1 model. From what I can see in the FEB file (tf_joint_FEBio_v2.feb), it appears that the prescribed kinematics are applied over the interval 0 to 1 s, but in version 1 this was done over the inte...

Hi Ahmet,
Thanks for your fast reply.
Problem solved! Everything seems to work fine with the newest FEBio version (v.2.2)
Thanks!
Todd