[pct-l] Heavy Backpacks May Damage Nerves, Muscles and Skeleton, Study Suggests

[Yoshihiro Murakami]

Dear Jeffrey

No need to worry about that article. The sciencedaily is a mass media,
which has some tendency to sensationalism.  It only suggested that the
heavy strain to the shoulders may damage to the soft tissues.

Today, no one carry 25 kg load on the shoulders. Their research
hypothesis was deviated from the real world. When the backpack weight
exceeds around 10 or 15 kg,   we know the pack weight should be
distributed to the waist.

To tell the truth, I am a professor of educational psychology,
specialized in psychological testing, measurement, and research
methodology. So, I am  nervous about the research design. Fortunately,
 the research design in empirical science, ( psychology, medicine,
life science etc. ) is all common. All the studies are not equal
value. Its evidence level depends  largely on their research design.

There are a few studies concerning pack weight and injury.

Hamonko et al (2011) may be the best research. They conducted the 1
year prospective randomized comparative research at the Rocky
mountaineering school. They examined the relation of real injury to
physical factors. They found  that the pack weight ( from 9.1 kg to
38.6 kg ) , age, gender, et al. had not related to the injury. ( UL
course was also included. )

The questionnaire method is inferior to the above method.  There are
two studies.

Lobb(2004) conducted questionnaire study to 2,403 trampers in New
Zealand. They found that the  packweight, age, and gender, et al had
not related to injury. Their average pack weight was 20 kg.

Anderson, et al.( 2009) carried out questionnaire methdod to 128 AT
and PCT hikers. They found pack weight, footwear had not related to
injury.

I am accidentally belong to this list, but I had learned very much
from American hiker, and very fortunately, I have written a hiking
handbook, which will be published in April or May. So I searched an
collected valuable scientific papers concerning hiking.


Reference

Hamonko, M.T., McIntosh, S.E., Schimelpfenig, T., \&  Leemon, D. \ \
2011 \ \  Injuries related to hiking with a pack during National
Outdoor Leadership School courses: a risk factor analysis. {\it
Wilderness Environmental Medicine}, 22, 2-6.

Lobb, B. \ \ 2004 \ \ Load carriage for fun: a survey of New Zealand
trampers, their activities and injuries. {\it Applied Ergonomics}, 35,
541-547.}

Anderson, L.S. Jr, Rebholz, C.M., White, L.F., Mitchell, P., Curcio,
E.P. 3rd, Feldman, J.A., \& Kahn, J.H. \ \ 2009 \ \ The impact of
footwear and packweight on injury and illness among long-distance
hikers. {\it Wilderness Environtal Medicine}, 20, 250-256.




-- 
Sincerely
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Hiro    ( Yoshihiro Murakami  村上宣寛 )
facebook  http://www.facebook.com/completewalker
Blogs  http://completewalker.blogspot.jp/
Photo  https://picasaweb.google.com/104620544810418955412/
Backpacking since 1980 in Japan, A foreign member of PCTA
JMT, 2009, 2010, 2011(half), 2012
Handbook of Hiking will be published in 2013
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