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View Full Version : MODELLING THE SHOULDER COMPLEX - Epilogue



A.w. Smith
08-09-1993, 12:23 AM
9 August 1993

Dear BIOMCH-L Subscribers,

About 11 days ago, I posted a request for information regarding the
shoulder complex. I would like to first, thank all of the responders
who took time from their busy schedules to share with us their advice
and experiences in this area. Second, as promised, what follows is a
summary (slightly edited) of the responses we received.

Thank you,

Drew Smith, PhD AWSMITH@UTCC.UTORONTO.CA

Director of Research
Lyndhurst Spinal Cord Centre
520 Sutherland Drive
Toronto Ontario CANADA
M4G 3V9 (416) 422-5551 x3041/3040 FAX (416) 422-5216

********* SUMMARY OF RESPONSES RE: SHOULDER BIOMECHANICS **********

1)
Date: Fri, 30 Jul 1993
From: Jonathan Dingwell

In regards to the shoulder complex, and the kinematics in particular,
there are several excellent papers written by A. E. Engin on modelling
of the shoulder complex. I have the papers at home and will bring in
the actual references on Monday, and send them to you. If you want to
look for them between now and then, try the J. Biomechanics, between
1980 and 1986 (or so).

2)
Date: Sat, 31 Jul 1993
From: winters@pluto.ee.cua.edu (Jack Winters)

Frans van der Helm is here through November, working with me. He's from
a group at Delft that is VERY active in the shoulder. He's at the smae
e-mail address: helm@pluto.ee.cua.edu

Jack Winters

3)
Date: Sun, 1 Aug 1993
From: "JOSEPH.MURPHY"

This is a brief response to your request posted on the list.
DuPuy Thackery is a company in England which we have frequent
dealings with. I know that they are researching into the
viability of shoulder prosthesis and given the complex nature
of the joint have done extensive engineering studies.
Since they are a commercial concern such data might be difficult
to tease from them. But you never know, a joint research
project might yeild useful source of capital? ...

----------------------------------------------------------
| "JOSEPH.MURPHY" |
| |
| Department of Orthopaedic Surgery |
| The Queen's University of Belfast |
| Tel: +44 232 669501 x2823 Fax: +44 232 661112 |
| |
| "We must learn to live together as brothers |
| or perish together as fools" |
| - Martin Luther King Jnr |
| |
|Opinions expressed here are personal and in no way be |
|considered as representing the institution above. |
----------------------------------------------------------

4)
Date: Sun, 1 Aug 1993
From: BI_RSMITH@cchs.su.edu.au

... Sandy Nicol is doing some work in this
area from Srathclyde. Also from Delft is Pronk (1991) The shoulder girdle
analysed and modelled kinematically. Johnson and Stuart, University
of Newcastleupon Tyne, UK have used Pronk's method. Dirkjan Veeger
from Vrije Universiteit Amsterdam also developed a method, modelled
from known static positions which he reported on here at our Human
Propulsion Conference. ...

Richard.

5)
Date: Mon, 2 Aug 1993
From: H=E=J=Veeger%FA%FBW@Zeus.fbw.vu.nl

..

Information on modelling of the shoulder complex can also be found in the
publication in Clinical Biomechanics 1993;8 81-90 (Veeger & Van der Helm,
Orientation of the scapula in a simulated wheelchair push"


Yours,

DirkJan Veeger

6)
Date: Mon, 2 Aug 1993
From: helm@dewey.ee.cua.edu

Dear Drew,

As a response to your posting at BIOMCH-L, I am happy to see that
the shoulder research work at Delft University has caught your eye.
The questions that you've raised are very valid questions, and
require a much more elaborate discussion than that is feasible by
e-mail. Therefore, I will give you a short opinion from my side, and
a brief outline of the present research at Delft and the
cooperating universities in the Dutch Shoulder Group, i.e. the Dept.
of Orthopaedics, Leiden University, and Fac. of Human Movement
Sciences, Free University Amsterdam.

1) Motion analysis of the shoulder girdle bones is extremely
difficult. External marker systems will not work, and 3D X-ray
requires markers implanted in the bones. We are using a static
method, in which bony landmarks are palpated and the 3D coordinates
are subsequently recorded. Then the position of the bone can be
reconstructed. The accuracy of the method is estimated to be 2-6 mm
standard deviation per coordinate of bony landmarks, well within the
(assumed) accuracy of video systems, in which the markers will move
with respect to the bones underneath.
Currently, we are extrapolating these static measurements to dynamic
situations. The justification for this procedure is tested using
X-ray films at Leiden University.

2) Strength measurements of individual muscles are not feasible for
the shoulder region (are they for any other part of the human
body?) without using some sort of a musculoskeletal model.

3) In Delft a very detailed musculoskeletal model of the shoulder
region has been developed, consisting of the thorax, clavicle,
scapula and humerus. Muscles are represented by a total of 95 muscle
lines of action, some of them wrapped around underlying bony
contours. The model has been applied for inverse static and inverse
dynamic situations, i.e. bony motions are input and the muscle
forces (or neural input) are calculated. For the inverse dynamic
situations a 3rd order non-linear muscle model is used (see e.g.
Winters & Stark, 1985), with roughly approximated muscle properties.
Currently, the latter approach is used for calculating muscle forces
for manual wheelchair propulsion, in a joint project with Free
University Amsterdam.

4) Presently, I am working at Catholic University of America,
Washington D.C., with prof. Jack M. Winters. Our goal is to develop
forward static and forward dynamic optimization algorithms for
shoulder motions. Part of the work is to assemble all available
knowledge of muscle, ligament and joint properties of the shoulder
region.

5) For your problem of spinal cord lesions, I can foresee two
approaches.

- inverse static/dynamic simulations, for which the shoulder girdle
motions must be recorded. This will be very interesting anyway for
this particular group of patients. Muscle forces can be estimated by
optimization procedures taking into account which muscles are
paralysed.

- forward static/dynamic simulations, with the same restrictions to
neural input as the first approach. However, the optimization of
these simulations is still under investigation.

6) My PhD-thesis, and two other recent PhD-theses from Delft
University of Technology will be sent to you, e.g.:

- Gijs M. Pronk (1991): The shoulder girdle, analysed and modelled
kinematically.

- Riender Happee (1992): The control of shoulder muscles during goal
directed movements.


I hope that this information will give you an idea of the work in
the Dutch Shoulder Group. There are a number of other projects
related to the subject. If you want more information, I will be
pleased to help you.
Application of the shoulder research to persons with spinal cord
lesions sounds very interesting to me. We are willing to share our
information, or help you out in another way. Maybe we can join our
common interest in the shoulder in a research project?

With kind regards,

Frans C.T. van der Helm
Dept. of Mechanical Engineering
Catholic University of America
620 Michigan Ave., N.E.
Washington, D.C.
U.S.A.
tel. (202)-319-5170
fax. (202)-319-4499
e-mail: helm@pluto.ee.cua.edu

As of November 1, 1993:
Dept. of Mechanical Engineering and Marine Technology
Delft University of Technology
Mekelweg 2
2628 CD Delft
The Netherlands
tel. (+31)-15-783812
fax. (+31)-15-784717
e-mail: wbmrasp@dutrex.tudelft.nl

7)
Date: Mon, 2 Aug 1993
From: mys@ip.chalmers.se (Mats Svensson)

A thesis on muscle strength was presented by Dan Karlsson at Chalmers
University of Technology in G|teborg, Sweden.

Dan Karlsson (1992): Force Distributions in the Human shoulder. Chalmers
University of Technology, Division of Mechanics, G|teborg, Sweden,
ISBN 91-7032-704-1


You can probably get a copy from:
Mrs Gunilla Ekman
Div. of Mechanics
Chalmers University of Technology
S-412 96 G|teborg
Sweden

Tel: +46 31 772 1515
Fax: +46 31 772 3477

Best wishes,

Mats Svensson

8)
Date: Mon, 2 Aug 1993
From: MEHTA01@swmed.edu

..

I am trying (in my spare time) to carry out a rough estimate analysis of
forces on the humerus when in a certain posture. I am interested in this
problem due to a number of accidents being reported in my favourite sport:
hang-gliding ... where the humerus fractured in flight and during landing.

... Could you possibly suggest the
best source for muscle orientation and action at the shoulder joint?

Thank you.

SHreefal Mehta

9)
Date: Tue, 3 Aug 1993
From: "Arthur E. Chapman"
To: awsmith@utcc.utoronto.ca

.. We are currently compiling a set of data from serial MRI scansof
the upper limb inorder to produce a model of the same which is amenableto
simulation. We have found that the Dutch group of Rozendal et al. at the
free UNiversity have made some strides in this direction. I should look up
their work. We haven't really faced the problem of the shoulder yet.
Best regards,
Arthur

10)
Date: Wed, 4 Aug 1993
From: "G.R.Johnson"

.. We also have a considerable interest in shoulder biomechanics. In
particular we have used the 3space isotrak system to study both humeral
and scapular movements using a palpator technique (Clin Biomech in press).
In conjunction with Univ of Newcastle NSW I have carried out a detailed
dissection study of 6 shoulders and digitised the points of attachemtn of
all muscles from radiographs. One paper on this is in press with Clin
Biomech nad we have published a paper on the measurement technique in J
Biomed Eng 1992, Vol 14, 490-494. The definitive paper on coordinate
attachments is in preparation for J Biomechanics and we hope to submit in
September or so. ...

I have a research student starting in October to look at the load bearing
charactersitics of the shouoder girdle in more detail.

..

Garth Johnson
Dept of Mech Eng
University of Newcastle upon Tyne
Newcastle upon Tyne NE1 7RU

tel: +44-91-222-6196
fax: +44-91-222-8600
email:g.r.johnson@newcastle.ac.uk

11)
From: Ulrich Berlemann

understanding the problems you are facing with the dynamic shoulder modelling I
at least have one good news for you: we recently have been in contact with the
Delft University in the Netherlands regarding the thesis you mentioned in your
mail. The Dutch have been so kind to send us a copy of it, which is now
available in our library. I would suggest that you do the same and contact

Dr. C.W. Spoor
Delft University of Technology
Lab. for Measurement and Control
Mekelweg 2
2628 CD Delft
The Netherlands

..

Best wishes from Bern, ULILI@MEM.UNIBE.CH