[pct-l] Backpack Packing strategies...

Thu May 5 22:30:45 CDT 2011

Good evening, Yoshihiro,

I have a question about your Interesting Point No. 1:  If more force is
necessary to move a large mass compared to a small mass; and if energy is in
terms of force applied over a distance, how can it be as you say that moving
a large mass over a distance requires less energy than moving than a small
mass over that same distance?

Steel-Eye

Hiking the Pct since before it was the PCT – 1965

http://www.trailjournals.com/steel-eye

http://www.trailjournals.com/SteelEye09

2011/5/5 Yoshihiro Murakami <completewalker at gmail.com>

> Dear treerings
>
> There are ergonomic experiments concerning load carriage: I found the
> article( Abea et al. 2007, Applied Ergonomics) last year. Now, his
> article is converted into PDF file and open to access.
>
> Interesting points:
>
> 1. The energy cost of walking significantly decreased during walking
> with load than without load at slower speeds. This means that the
> energy cost does not increase as the load increase, contrary to the
> expectation:
>
> 2. A significant decrease in the energy cost of walking was also
> observed while carrying the load on the upper back than on the lower
> back at 60-80 m/min. The load on the upper back is superior to the
> lower back load.
>
> You can read PDF file at http://bit.ly/jkAinW  . Please see Fig.2
>
>
> Abstract
> We examined the effects of load carriage position on the energy cost
> of walking defined as the ratio of the 2-min steady-state oxygen
> consumption to the speed and economical speed. Fourteen healthy men
> walked on a treadmill at various speeds without and with load on the
> lower and upper back, which corresponded to 15% of their body mass.
> The energy cost of walking significantly decreased during walking with
> load than without load at slower speeds. A significant decrease in the
> energy cost of walking was also observed while carrying the load on
> the upper back than on the lower back at 60-80 m/min. The economical
> speed significantly decreased when carrying the load on the upper and
> lower back, and it was significantly correlated with body height.
> These findings suggest that an optimal carrying method is evident to
> reduce physical stress during walking with loads.
>
>
>
>
>
>
>
> 2011/5/6  <treerings at gmail.com>:
> > I think the video author misses the fact that as the center of gravity
> > lowers it becomes less important to place the pack load vertically over
> the
> > weight-bearing hips. In other words, packing all the heavy stuff in the
> > bottom doesn't necessitate leaning over at a right angle just to keep the
> > load vertically over the hips. That seems a little silly.
> >
> >
> > On Fri, Apr 29, 2011 at 10:21 PM, John Abela <
> > pacificcresttrail2011 at gmail.com> wrote:
> >
> >> Hello,
> >>
> >> First, spend 8 minutes of your life and watch this video:
> >>
> >> http://www.youtube.com/watch?v=2wuwNnRfrG4
> >>
> >> I would not be able to comment on this overall too much. I have gone
> >> from using a 4,200 cubic inch (68.8 liters) backpack to a 2,600 cu in
> >> (42.6 liters) and I have just placed an order for a 1,000 cu in (16.3
> >> liters) backpack that I am hoping beyond all hope I will be able to
> >> get my gear into. However what I can comment on is that a good deal of
> >> it depends upon the design of your bag. These days with things like
> >> Backpack lids/brains, it is just totally screwing up how to properly
> >> go about packing a backpack. Best thing I ever did was order a custom
> >> made backpack with no outside pockets (except for two shoulder
> >> pouches). Not only does it force me into properly packing a backpack -
> >> and not having to counter balance with outside pocket weight - but it
> >> results in zero snags with trees and bushes.
> >>
> >> I think there are so many different "suggestions" out there on the
> >> internet that it just really makes most people lost in what is
> >> 'right'. Watch the video and stop and think about everything you might
> >> be reading on the internet about this issue. It will so totally
> >> disprove the vast majority of what you are probably reading.
> >>
> >> Not a lot of info I can share on this fact beyond what I have. I am
> >> sure if you provided some further details on the pack you have and the
> >> amount of gear you have and what your big-three are, it could help
> >> some folks help you with some initial suggestions!
> >>
> >>
> >> John B. Abela
> >> www.RedwoodOutdoors.com
> >>
> >> On Fri, Apr 29, 2011 at 9:58 PM, Guthrie Nutter
> >> <guthrie.nutter at gmail.com> wrote:
> >> > *sheepish look*
> >> >
> >> > Having a bit of an 'adventure' with my amateur attempts to pack a
> >> backpack
> >> > properly.  Maybe doing a better job than anticipated, but need the
> extra
> >> > confidence booster.
> >> >
> >> > Anyone know of any good articles I can read on about how to actually
> >> > visualize the layout of where to put everything?  Ideally I would
> prefer
> >> to
> >> > see a hands-on demo at ADZPCTKO, but it's not possible.  Starting
> 5/17.
> >> >
> >> > If there's anyone on this list serv in the NYC area, holla in this
> >> > direction, and we can get a conversation going.  See you on the trail!
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>
>
> --
> Sincerely
> --------------- --------------------------------------
> Hiro    ( Yoshihiro Murakami  村上宣寛 )
> Blogs http://completewalker.blogspot.com/
> Photo http://picasaweb.google.co.jp/CompleteWalker/
> Backpacking since about 1980 in Japan
> 2009 JMT, the first America.
> 2010 JMT, the second America.
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