Problems with model arm26.osim

[Giovanni Ferreira]

Hi

I'm having some problems with model arm26.osim

First, the coordinates window doesn't contain the X,Y,Z axis sliders as well as there's only flexion/extension joint rotation sliders. The glenohumeral abduction, adduction and external/internal rotation sliders are missing!

Second, many muscles are missing. Actually, only Biceps, Triceps and Brachi are displayed. Maybe because there's only flexion/extension movements available...

Can somebody help me?

Thanks a lot

Giovanni Ferreira

[Giovanni Ferreira]

and i'm using OpenSim 1.9
The 2.02 doesn't work here.

[Ayman Habib]

Hi Giovanni,

The coordinate sliders reflect what's in the model file. The Arm26 model has only 2 degrees of freedom and 6 muscles (hence the name Arm26 and is used only for educational purposes as a highly simplified model. There're many other models of the Upper Extremity that offer many more degrees of freedom at the expense of complexity.

Hope this explains,
-Ayman

[Giovanni Ferreira]

Ayman,

sorry for my ignorance, but where can I find those models?

[Ayman Habib]

Hi Giovanni,

There's no specific model that we endorse, actually we're working with some model developers to come up with one that hits the right balance between functionality and complexity. An example that's on the high complexity side (that I would recommend only for kinematic analysis) is available on simtk.org at
https://simtk.org/home/up-ext-model

Cheers,
-Ayman