Knee model, Shoulder model and Sit-to-stand

Good morning everyone,

I am currently studying different aspects of the sit-to-stand transition in
normal and aging subjects and I’ve been planning (for almost a year now, but
other things came up) on using anybody to model this activity. As I was
revising the documentation about anybody, and more specifically the
repository (Anybody Research Project) publications, I stumbled upon the
internship report of Peter Eshuis (2004) on the improved knee model. This
report is very interesting for two reasons: first, it is a remarkable
example of the sequence of steps required to build a model with anybody,
second, it is documenting the knee modelling and validation, which is very
important when citing that you are using the full body model. My questions
are:

  1. Is there a similar document documenting in detail the shoulder
    model? I noticed a short document (2001) that describes the shoulder model,
    but a comment about a more recent document by Mr. Rasmussen (2004) seems to
    invalidate that description: “Please notice that the conclusions of this
    abstract are now deprecated. The shoulder model is now much more robust
    towards segment positions”.
  2. In Peter’s report, part of the validation is done using a
    sit-to-stand model. I notice that this model does not seem to be available
    in the repository (v6). Did I just miss it? Will it eventually be added? Is
    there a way I can get access to it?

I thank you all very much,

Jean-Olivier Racine

Laboratoire d’imagerie et d’orthopédie

École de technologie supérieure

Montréal, Québec

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Dear Jean-Olivier,

> 1. Is there a similar document documenting in detail
> the shoulder model?

Yes, in a sense. The shoulder model is an almost exact replication
of the Dutch shoulder model by van der Helm and others, and they
have reported the development of the model extensively. If you look
up van der Helm on Pubmed you will find most of the papers.

Bergmann has recently reported data from an instrumented shoulder
prosthesis, and I know that one of our users is working on
validation of the model against these data.

> I noticed a short document (2001) that
> describes the shoulder model, but a comment about a more
> recent document by Mr. Rasmussen (2004) seems to
> invalidate that description: “Please notice that the
> conclusions of this abstract are now deprecated.
> The shoulder model is now much more robust
> towards segment positions”.

The initial version of the model had some elements that were
sensitive to posture and placement, but we corrected that a long
time ago, and in the current model it does not seem like the results
are very sensitive to the scapula position, which was the problem in
the early model.

Incidentally, we have just in these days a visitor from your
university, Yoann Collet, who is working on the shoulder model and
comparing results to in-vitro experiments. I think that it might be
helpful for you to contact Yoann.

> 2. In Peter’s report, part of the validation is done
> using a sit-to-stand model. I notice that this model does
> not seem to be available in the repository (v6).
> Did I just miss it? Will it eventually be added? Is
> there a way I can get access to it?

That is a good question. I think we had it in the repository a long
time ago, and I am frankly not sure why or when it disappeared. I
know that the model was developed by another AnyBody user who is
right now orking on a publication about the matter, so perhaps the
model will make its way back into the repository. But it is a bit
out of our control because it is not really developed in the AnyBody
group.

It would not be difficult to make a new sit-to-stand model based on
the standing model of free posture model in the repository. In fact,
another visitor who just left us developed such a model based on
motion capture data during a couple of days. An option might be to
ask him whether he would share his model with you. Let me know if
you are interested, and I will try to establish the contact.

Best regards,
John (The AnyBody Research Group)

Hi again,

Thank you for that answer, quite useful information.

I was not aware Yoann is currently with you. I find it quite amusing. I
guess he’ll be a quite valuable resource on future shoulder issues.

As of the Sit-to-Stand model, I certainly would be interested in seeing the
Full Body model you are describing. It would certainly make a great starting
point. So I gladly accept your offer.

Thanks for your help!

Jean-Olivier Racine


From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of AnyBody Support
Sent: 22 septembre 2006 11:08
To: anyscript@yahoogroups.com
Subject: [anyscript] Re: Knee model, Shoulder model and Sit-to-stand

Dear Jean-Olivier,

> 1. Is there a similar document documenting in detail
> the shoulder model?

Yes, in a sense. The shoulder model is an almost exact replication
of the Dutch shoulder model by van der Helm and others, and they
have reported the development of the model extensively. If you look
up van der Helm on Pubmed you will find most of the papers.

Bergmann has recently reported data from an instrumented shoulder
prosthesis, and I know that one of our users is working on
validation of the model against these data.

> I noticed a short document (2001) that
> describes the shoulder model, but a comment about a more
> recent document by Mr. Rasmussen (2004) seems to
> invalidate that description: “Please notice that the
> conclusions of this abstract are now deprecated.
> The shoulder model is now much more robust
> towards segment positions”.

The initial version of the model had some elements that were
sensitive to posture and placement, but we corrected that a long
time ago, and in the current model it does not seem like the results
are very sensitive to the scapula position, which was the problem in
the early model.

Incidentally, we have just in these days a visitor from your
university, Yoann Collet, who is working on the shoulder model and
comparing results to in-vitro experiments. I think that it might be
helpful for you to contact Yoann.

> 2. In Peter’s report, part of the validation is done
> using a sit-to-stand model. I notice that this model does
> not seem to be available in the repository (v6).
> Did I just miss it? Will it eventually be added? Is
> there a way I can get access to it?

That is a good question. I think we had it in the repository a long
time ago, and I am frankly not sure why or when it disappeared. I
know that the model was developed by another AnyBody user who is
right now orking on a publication about the matter, so perhaps the
model will make its way back into the repository. But it is a bit
out of our control because it is not really developed in the AnyBody
group.

It would not be difficult to make a new sit-to-stand model based on
the standing model of free posture model in the repository. In fact,
another visitor who just left us developed such a model based on
motion capture data during a couple of days. An option might be to
ask him whether he would share his model with you. Let me know if
you are interested, and I will try to establish the contact.

Best regards,
John (The AnyBody Research Group)

.

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