View Full Version : Re: Inverse Dynamic Computer Program

John Rasmussen
08-07-2002, 08:49 PM

I think the AnyBody project can help you.

> I am a doctoral student currently working on my dissertation. My research
> topic is three-dimensional reaction forces and muscle moments occurring at
> the shoulder joint during wheelchair propulsion over different types of
> terrain. I have been unsuccessful in my attempts at writing a
> three-dimensional inverse dynamic model computer program.

The shoulder is a very complex mechanical system - one which multiple and
very competent research groups have worked on for decades. It is very
unlikely that you would be able to write software and build a valid model
from scratch in the context of your dissertation.

> I do have the
> means of directly measuring three-dimensional reaction forces and moments
> the pushrim. The particular model I have selected to incorporate into my
> study was developed by Vrongistinos (2001). It is similar to Dr. Cooper's
> model but incorporates certain equations from Wittenburg (1977). The
> inertial data will be calculated according to Winter (1990). What are
> other inverse dynamic models that might serve my purpose? Are there any
> three-dimensional inverse dynamic computer programs available?
> downloadable?

AnyBody is such a system. It is currently in alpha releases, and
particularly interested researchers who are willing to put up with the
errors and deficiencies of early software can apply to become alpha testers
at the AnyBody project's home page: http://anybody.auc.dk

The software gives you the basic facility to develop 3-D inverse dynamics
models of any complexity you like. You can literally have hundreds of
muscles in play. However, the design of models is still a large and
difficult job. For that reason, we put all our models in the public domain
and hope that other researchers will contribute to the improvement and
validation of them.

We are currently in the process of replicating the Dutch shoulder model in
the system. We expect that this model will be operational within a few
weeks. Following that stage comes a long testing period with adjustments and
validations. We are very interested in having other users such as you
working with and improving the model.

Best regards,

John Rasmussen
The AnyBody project, Institute of Mechanical Engineering, Aalborg
University, Denmark.
http://anybody.auc.dk email: jr@ime.auc.dk

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