I would like to use a sole shoulder model (without the rest of the
body–to save computation time) for a project I am working on, however
I have found some differences in analyses between a sole shoulder
model and the standing model. The shoulder model is the ‘Abduction’
file in the files section, and the standing model is standard standing
model that comes with the repository. I have run a static analysis for
both models with a vertical load at the hand of -50N (GH flexion =
30deg, GH abduction = 30deg, GH rotation = 0, elbow flexion = 0.1,
elbow pronation = 0) and am looking at muscle forces. For the shoulder
model, the shoudler muscle forces are generally about 50-80% higher
than those of the standing model. Is this because the shoulder model
doesn’t have other muscle to share the load? Or, is there a difference
between the sole shoulder model and the should in the standing model?
Thanks.
I have just spend some on debuging this problem, i think the problem
is the extra load which is added in the environment.any file of the
abduction file, here an extra load 50N is added!!. So i removed this
and created a model like you described. It gives almost identical
results for the forces in the shoulder. They should not be 100%
identical because there is a coupling between the shoulder and the
spine, and the spine have differnt strength using the muscles or
not.
Best regards
Søren, AnyBody Support
— In anyscript@yahoogroups.com, “chrisjgatti” <cjgatti@…> wrote:
>
> I would like to use a sole shoulder model (without the rest of the
> body–to save computation time) for a project I am working on,
however
> I have found some differences in analyses between a sole shoulder
> model and the standing model. The shoulder model is
the ‘Abduction’
> file in the files section, and the standing model is standard
standing
> model that comes with the repository. I have run a static analysis
for
> both models with a vertical load at the hand of -50N (GH flexion =
> 30deg, GH abduction = 30deg, GH rotation = 0, elbow flexion = 0.1,
> elbow pronation = 0) and am looking at muscle forces. For the
shoulder
> model, the shoudler muscle forces are generally about 50-80%
higher
> than those of the standing model. Is this because the shoulder
model
> doesn’t have other muscle to share the load? Or, is there a
difference
> between the sole shoulder model and the should in the standing
model?
> Thanks.
>
> Chris
>