Hi Robert -

Check the biomch-l archives. There was a similar question about this in the
last two years. I also remember a presentation on this topic at a
conference. I believe it was at ACSM in Indianapolis (1996). Good luck!


Check out the following ref. Pascoe et al(1997) Ergonomics v.40, p631-641
entitled - Influence of carrying book bags on gait cycle and posture of


David Davis
Researcher in Biomechanics and Load Carriage
Department of Human Sciences
Loughborough University
LE11 3TU
Tel: (UK) +1509 223086
Fax: (UK) +1509 223941
There have been a few studies in this area, but I don't recall the
references. I have seen them in journals not listed in medline (such as
Applied Ergonomics and International Journal of Industrial Ergonomics) and
conference abstracts.

Don Bloswick of the University of Utah had some students studying the
biomechanics of bag carrying, but that may have been mailbags.

Best of luck tracking this down.


p.s.: You may also want to check the literature on shoulder nerve
entrapment, because that is the disorder that I have heard may be related
to excessive load in shoulder straps of book bags.

The National Back Pain Association here in the UK are promoting a
range of schoolbags because of this problem. They launched them last

Their address is

1 Geron Way,
London, NW2 6LW

Phone +44 181 450 4549
fax +44 181 450 2321
NBPA Schoolbag hotline +44 181 830 7559

Excuse my possible lack of knowledge in the specific area of your question
but didn't the Australian government do research into postal workers and
the carrying of bags in the late 80's early 90's? my other point is that
from reading through the lit it seems there are no problems if the kids
carry a backpack with both straps over the shoulders, the army have done
work like this in the US and the UK. It is a different scenario, where the
loads are much higher but may give you a starting point, I remember some
mail about backpacks on biomech-l about a month or two ago, follow the
e-mail thread and may give you some links!

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Ross Anderson Tel - +353 (0)61 202820
P1007 Sports Building Fax - +353 (0)61 330431
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IRELAND e-Mail -

Dear Robert:

I think It might be useful having a look in:

"An Investigation into the postural changes associated with load carriage
using two different rucksack designs" by R.Lloyd; C.B Cooke. Abtract into
Proceedings of the third annual congress of thye European college of Sports
Science (1998), pp. 351 and 352 - Manchester, UK.

I dont think you will be able to get the article very easily (Obviously,
guessing). The only info I have is about the address of the authors is that
they are based in the School of leisure and Sports Studies, Leeds
University, Leeds, UK.

I hope it is useful information for your purposes

Sincerely yours

Andre Rodacki

Robert, i do not have information directly related to schoolbags
but i do know that the Sports Science department at Liverpool John Moores
University have carried out and published studies relating to the carrying
and design of postbags, therefore they may be a good port of call. Hope
this is of some help.

Cheers, all the best

David Philip Cook
Brunel University, UK

Dear Robert,

A study in this area has been underway in the School of
Physiotherapy, University of South Australia, North Terrace, Adealaide S.A.
5000. Lecturer Lucy Chipchase ( would know the

Best wishes,

Trevor Hearn Ph.D.
Professor and Chair, Orthopaedic Research

Here are a few I recently found in a search for backpack research in
general... I hope they help!

DeVita, Hong, & Hamill (1991) J. Biomechanics 24(12) 1110-1129. Effects of
asymmetric load carrying on the biomechanics of walking.

**Pascoe, Pascoe, Wang, Shim, Kim. (1997) Ergonomics. 40(6) 631-641.
Influence of carrying book bags on gait cycle and posture of youths.

Megan Dailey
Exercise and Movement Science, PhD student
University of Oregon


Dr. Newton -

I am responding to your posting on BioMch-L in which you request information
on research into, and possible orthopedic problems associated with backpack

I don't recall the specific name of the study (still looking) that was done,
however it was based on the prevalence of shoulder type injuries/complaints
of women carrying shoulder bags/purses that were overloaded. The MD that
assisted my mother with this type of problem referenced the study in her
course of care, and prescribed shoulder rehab exercises to heal and
strengthen the shoulder.

I will forward any further info as I receive it - just thought I might
provide some input.....

Good Luck


Eric O. DeMar, MA, ACSS

This came up as an issue with adults on ergoweb over the last month. I
could forward your mail to that list if you wish.

I was contacted about 2 years ago by someone asking a similar question, also
relating the issue to the Anthropometrics of children. I found some leads,
but nothing very "hard." I didn't search in medline, but found a web
resource through a social outreach organization.

Because I am now a graduate student myself, I have access to other databases
besides medline. Perhaps some allied health databases would be more

Let me know if you want me to foreword your mail to ergoweb. If you wish
you can go to the site and sign up yourself. Search ergoweb.

Beverly Burke RN
Movement Systems

Certified Movement Analyst
Certified Industrial Ergonomist


Standard disclaimers apply.
My friend, Wunpen Chansirinukor, has done a research about school backpacks
for her Masters degree (in Physiotherapy) at Univeristy of South Australia
(in Adelaide). There are also few other students (in both Masters and PhD
programs) doing research in this area at the School of Physiotherapy,
Univeristy of South Australia.

Wunpen's e-mail address is I hope this
would help.




Dear Robert,

My students did a study on the backpack type of bags, which are
extremely overloaded in Hong Kong! They examined the effect of 20% body
weight bags, using 2D kinematics and kinetics. Main finding was
increased stance knee extensor moments and powers (both eccentric
loading, K1, and concentric, K2, powers). I haven't sent this study off
for publication, because my software is not yet written up, but you're
welcome to the results.


Dr. Chris Kirtley MD PhD
Dept. of Rehabilitation Sciences
The Hong Kong Polytechnic University
Hong Kong
Special Administrative Region of The People's Republic of China

Contact Maree Williams, Physiotherapy Department, University of South
Dan Barker
Research Engineer
Department of Orthopaedics
Repatriation General Hospital
Daw Park, 5041 SA
Ph: +618 8275 1107
Fax: +618 8374 0712

Dear Dr. Newton,
I am a first year graduate student in Department of Sports Science
and Physical Edcuation at the Chinese University of Hong Kong. My thesis
topic is also about carrying school bags by children. As a matter of fact,
there is very little information about school bay carriage by children. I
think this papers can help you. All of them are about carrying school bag.
Pascoe, D. D., Pascoe, D. E., Wang, Y. T., Shim, D. M. and Kim, C.
K. (1997). Influence of carrying book bags on gait cycle and posture of
youths. Ergonomics, 40(6), 631-641

Hong, Y., Li, J. X., Wong, A. S. K. and Robinson, P. D. (1998),
Weight of school bags and the metabolic strain created in children. Journal
of Human Movement studies, 35(4), 187-200
(Dr Hong Youlain is my supervisor)

Wong, A. S. K. and Hong, Y. (1997) Ergonomics analysis on carrying
of school bags by primary school children. The Hong Kong Journal of Sport
Medicine and Sport Science. (If you want to get a copy of this article, I
can send you a copy by mail)

I hope that these information can help you. Thank you.

Cheung Chi Kin
Department of Sports Science and Physical Education,
The Chinese University of Hong Kong,
Shatin, N.T.,
Hong Kong,

Hello Dr.Newton
Medline as you know does not index all the rehabilitation literature, which
may be why you can not find your information.
Exerpta Medica may be another index you want to look at.
If you still come up empty, you may want to build your case on adult
Good Luck.
Désirée Maltais

I believe a question about backpacks came through the biomec-l a few months
ago and some answers were posted (but I could be mistaken). Did you check
the archives?

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Gordon Chalmers, Ph.D.
Dept. of Physical Education, Health and Recreation
Western Washington University, MS-9067
Bellingham WA


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Senior Lecturer
Director of Postgraduate Studies and Research
School of Exercise Science and Sport Management
Southern Cross University
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