View Full Version : summary:pelvic movement in seated reaching

Trisha Bate
06-24-1997, 04:11 PM
Thankyou for the replies to my enquiry regarding axes of pelvic motion
during seated reaching. Herewith the replies I received:

I had a graduate student write his MS thesis on "Influence of Motor Vehicle
Seat Geometry on Pelvic Inclination." He described an axis of pelvic
rotation under the ischial tuberosities in his thesis. The student's name
is George J. Beneck. He is a physical therapist practicing in California.
His results are the same as hypothesized by Gunnar Andersson et al. several
years ago in Spine vol 4: 52-58, 1979.

Hope this helps.

Mac Reynolds, Ph.D.
Professor and Director
Ergonomics Research Laboratory
Michigan State University
Voice: 517-487-1702
Fax: 517-487-2023

I don't believe anybody has looked at hip and pelvic motions during reaching
movements, or at least I havn't been able to find any such work. We are
studying it currently (reaching while standing) and we are finding a
gender-related difference in the relative motions at the spine and the hip.

The following papers, dealing with trunk movement and/or muscle activity
associated with reaching movements, may be of interest to you.

Kaminski, Bock & Gentile, Exp. Brain Res. 106: 457-466 (1995).

Tyler & Hasan. Exp. Brain Res. 107: 87-95 (1995). [This is about trunk
muscle EMGs associated with reaching while sitting.]

I would appreciate learning about your investigations.

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: Ziaul Hasan \ :
: University of Illinois at Chicago (M/C 898) \ :
: 1919 W. Taylor Street, AHP Rm. 447 \ :
: Chicago, IL 60612-7251, U.S.A. / :
: .^. / :
: Phone: Voice 312-996-1504, Fax 312-996-4583 ( )_____/ :
: E-mail: zhasan@uic.edu ~~~ :
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I am sorry I don't have any info for you, but I would like any info you
receive. I am interested in the influence of hippotherapy (therapy using
the horse) on movement coordination of the trunk, and knowing the axis of
rotation while ischial tuberosities are weight bearing would be
interesting to me.
THanks and Good Luck!
Victoria Haehl
Indiana University
Department of Kinesiology
HPER Room 112
Bloomington, IN 47408
(812) 855-3061

Dear Bate,

There is a paper dedicated to find an axis of the pelvis in a sitting

- Brodeur, R.R., Cui, Y. & Reynolds, H.M. (1996). Locating the Pelvis in
the Seated Automobile Driver. S.A.E. Technical Papers Series No. 960481.

with the best regards
Rachid Aissaoui,
Industrial Chair on Seating Aids
Dept. of Mechanichal Engineering,
Ecole Polytechnique de Montreal,


I cannot help you directly, but...

If you have access to Medline, you should be able to find the information that
you seek. Medline can be accessed via web browsers and at medical libraries.
If no electronic search resources are available, you may be able to find the
info in print media at the nearest medical library.


Thomas G. Loebig, MSME
Biomechanics Resarch Lab
Allegheny University of the Health Sciences
320 E. North Avenue, 10th Floor South Tower
Pittsburgh, PA 15212
412.359.6773 FAX: 412.359.3238


I did some work on seating several years ago. I don't recall seeing
anything at that time related to your query. All I can suggest are
the obvious sources such as anatomy textbooks (e.g. Gray's Anatomy),
journals such as Clinical Biomechanics, and databases such as MEDLINE.

Andrew Pinder
Health and Safety Laboratory
Broad Lane
S3 7HQ


Dear Tricia
I also do not know of any references directly answering your question, but I
do have a few comments. My research is related to seat contours. These
contours change with changes in posture such as reaching, leaning back or
forward. It seems that some movements, or with some people, their ischial
tuberosities essentially are the piviot point and with others the ischial
tuberosities "slide" anteriorly or posteriorly while the skin contact with
the seat remains stationary. In short, the axis of rotations will vary with
type and configuration of seating, functions being performed and the
individual's movement patterns.

I would be interested to hear more of your research as it may relate to my
current studies.

Neil Tuttle

__________________________________________________ _______________________
Trisha Bate | "for the sun and the sea and the
School of Physiotherapy | pipes of pan are our birthright"

Faculty of Health Sciences
Latrobe University
Phone :61(0)39 2855 259 or:61(0)3 9481 1718
Fax : 61 (0)3 9285 5225 EMAIL P.Bate@Latrobe.edu.au

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