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Richard Baker
08-02-2000, 06:59 PM
Yesterday I asked about some inconsistencies in the reporting of Dempster's
anthropometric data (full query below). Thanks to Pascale Pigeon, Jim
Patton, DI Miller (himself!), and D Gordon E Robertson for supplying the
following references:

Miller D and Nelson R (1973) Biomechanics of Sport: A Research Approach, Lea
and
Febiger, Philadelphia.

Plagenhoef S, Evans FG, Abdelnour T (1983) Anatomical Data for Analyzing
Human
Motion, Research Quarterly for Exercise and Sport, Vol 54, No 2, pp 169-178.

Plagenhoef S (1971) Patterns of Human Motion: A Cinematographic Analysis,
Prentice-Hall, Inc., Englewood Cliffs, New Jersey.



Gordon also supplied the following explanation and two web-site references
which will be interestingly to anyone working in this field. I reproduce his
comments in full:


When you add up the proportions that Dempster and Plagenhoef report the
total body does not add up to 100%. This was attributed mostly due to fluid
and flesh losses during the dissections of the cadavers. Miller and Nelson
report values where they redistributed the missing mass proportionally
throughout
the body parts to the totals add up to 100%. Plagenhoef also added some
proportions for dividing the trunk into several parts etc. I recently went
through
all four sources (Dempster, Plagenhoef, Miller & Nelson and Winter) to
obtain
a comprehensive list of the proportions. You can find them plus the various
equations at:
http://www.health.uottawa.ca/biomech/csb/ARCHIVES/dempster.pdf

You can also view a similar table for the proportions developed by Clauser
et al. and Chandler et al. It is found at:
http://www.health.uottawa.ca/biomech/csb/ARCHIVES/clauser.pdf
Clauser (and Chandler) used bony landmarks instead of joint centres of
rotation
as their segment end points so don't expect the "r" and "k" values to be the
same. Definitions of their landmarks are provided with the table.

These data are contained in the Canadian Society for Biomechanics website
at:
http://www.health.uottawa.ca/biomech/csb/



Thanks to all of you and also to all you guy's keeping Biomch-L up and
running. It's a great system!

Richard


Original question:

I'm reviewing Dempster's 1955 data on the position of the centre of mass of
different body segments. I've got a copy of the original report which
appears to contain a couple of typographical errors (e.g. position of CM of
lower leg with and without foot is identical). Winter (Biomechanics of Human
Movement, John Wiley, 1979 p151) cites Dempster but gives different values
which look more convincing (0.433 from knee without foot, 0.606 with).
Winter cites the data as having come "via Miller and Nelson" or "via
Plangenhoef".

Does anyone out there have an explanation for this or know a reference for
either Miller and Nelson or Plangenhoef?

Richard Baker PhD
Gait Analysis Service Manager
Musgrave Park Hospital, Stockman's Lane, Belfast, Northern Ireland, BT9 7JB
Tel: +44 2890 669501 ext 2155 or 2849
Fax: +44 2890 382008

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