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Future Of Backpacks

Posted: Thu Nov 30, 2017 3:00 pm
by maverick
Outside Magazine:
In practice, of course, walking—with or without a pack—does take effort. With each step, your center of mass rises and falls in an arc, like an upside-down pendulum. Back in 2002, Donelan and his colleagues showed that much of the energy you burn while walking comes from the transition from one pendulum swing to the next: negative work by the knee joint to brake as your foot lands, then positive work by the ankle to push off again.

So when you strap a pack on, the actual cost of supporting the pack against gravity isn’t a big deal. Instead, it’s decelerating and then reaccelerating it with each step that costs energy—which is why some researchers are pursuing ideas like suspended packs that counteract some of this up-and-down motion. That can offer big savings on level ground; once you start climbing a hill, though, then you can’t avoid spending energy to hoist the pack against gravity.

Of course, energy cost isn’t the only consideration in backpack design. Pigman, who is now working on a Ph.D. in biomechanics at the University of Delaware, has further data coming out soon on force transmission to various parts of the body. Hip straps are supposed to redistribute force from the shoulder muscles to the much larger muscles around the hips, which should improve comfort and fatigue resistance, even if you burn the same amount of energy overall. They also reduce the risk of “rucksack palsy” resulting from compressed nerves under the shoulder strap.
Where is the most efficient place to position a load? Believe it or not, it’s on your head. Women in Kenya and other East African countries, researchers reported in the 1980s, carry up to 20 percent of their body weight either balanced on their heads or supported by a strap around their foreheads (like porters in Nepal sometimes use) without expending any extra energy. The problem, as a review in Military Medicine points out, is that it takes too long to learn how to do this.
https://www.outsideonline.com/2251986/s ... nsiteshare

Where do you see the future/evolution of backpacks? Thur-hikers carrying some sort of rucksacks on their heads? :)

Re: Future Of Backpacks

Posted: Thu Nov 30, 2017 3:38 pm
by RichardCullip
"....Where is the most efficient place to position a load? Believe it or not, it’s on your head. Women in Kenya and other East African countries...."

We saw that early in Nov on a trip to Uganda. Never saw any men carrying loads that way. Just the women.

Re: Future Of Backpacks

Posted: Thu Nov 30, 2017 4:21 pm
by freestone
RichardCullip wrote:"....Where is the most efficient place to position a load? Believe it or not, it’s on your head. Women in Kenya and other East African countries...."

We saw that early in Nov on a trip to Uganda. Never saw any men carrying loads that way. Just the women.
Patagonia agrees. I believe what you are referring to is called a "Tumpline"

http://www.patagonia.com/product/patago ... rt=1&sz=24

Re: Future Of Backpacks

Posted: Thu Nov 30, 2017 9:48 pm
by Wandering Daisy
Tumplines probably would not work as well as the weight increases. A tumpline would seem to restrict your agility, so may be good for carrying loads on roads and relatively flat tread (such as trails), but may not be the best off-trail and rock scrambling. Maybe that is why the men do not use tumplines- perhaps they concentrate on hunting, which requires more agility. Or maybe it is just carrying water and such is considered women's work.

RJ Secor used a tumpline on a few trips I did with him. But then, his pack never weighed that much- he was a minimalist.

Carrying on your head is efficient because the weight is directly along your center-line. But literally on your head would be tricky to balance while climbing up talus! Actually, the old external frame packs, with the upper bar (extender bar) are the best at getting the load directly on your centerline. With these packs, we always carried weight high when on a trail and low on terrain that required more body movement and climbing.

I have seen people with packs that have sides both in front and back. I wonder if that idea will amount to much.

I would like to see the "future of packs" get back to external frame packs, but with super light frame material. I would also like to see custom fit to your individual back, sort of like fitting a ski boot to a foot. Seems like with computers/ measuring/ 3d printing, and such that everyone could have a frame exactly fit to them.

Re: Future Of Backpacks

Posted: Fri Dec 01, 2017 10:09 am
by John Harper
Wandering Daisy wrote: Seems like with computers/ measuring/ 3d printing, and such that everyone could have a frame exactly fit to them.
Sounds like an excellent vision of the near future.

John

Re: Future Of Backpacks

Posted: Fri Dec 01, 2017 11:06 am
by longri
Men use tumplines all the time in places like Nepal. It's probably true that it has advantages. I can think of a couple of well known westerners who have tried it and found that it worked very well. But it would be a little scary to try and learn this as an adult.

I've tried carrying items on my head, the way I've seen women in Africa do so gracefully. I carried a large box on my head about a mile one time. While it was up there it really did feel a lot better than carrying it in my arms. But I couldn't keep it there for very long without using my arms to maintain it's position. It seemed like a circus balancing act. I'd probably have to practice for months or years to be halfway competent at it.

I'm skeptical that some future high tech backpack frame technology is going to make a significant difference in actual practice. My large capacity backpack has what the maker calls a sophisticated suspension that moves independent from one's body, pretty much what the guy in the quoted article was suggesting. But it's just a pack that came with some marketing blather.

In the end the most efficient method is to have someone else carry the load for you.

(edited to correct typos)

Re: Future Of Backpacks

Posted: Fri Dec 01, 2017 12:10 pm
by maverick
In the end the most efficient method is to have someone else carry the load for you.
:nod:

Or something else (horse).

Re: Future Of Backpacks

Posted: Fri Dec 01, 2017 2:41 pm
by Hobbes
The future of backpacking is already here - and has been for at least a decade or more. It's based on materials technology to simultaneously reduce weight and increase performance: strength, warmth & moisture. The current products go by the names everyone recognizes: nylon, cuben, down, GTX, etc. The technology development was originally driven by military applications - as always - which has filtered down to the consumer marketplace.

Even better, just like in other areas of technological improvements eg cell phones, computers, imaging, etc, materials technology isn't static. Rather, there is constant & ongoing research into applications to deliver the big 4: lighter, stronger, warmer & drier.

Let's take down for instance. A decade ago, 600fp+ was still a big deal. Now, 800fp would be considered the bare minimum for a high quality jacket and/or sleeping bag. Patagonia has some 1000fp parkas that are quite expensive, but the trend line is evident. The key to producing more dense goose down is no different than breeding bigger, plumper chickens: genetics, either selective breeding or DNA manipulation. Perhaps within a decades, 1000fp will be used for cheap, commercial knock-offs, while premium will be double what we have today.

From an engineering standpoint, there's no technical reason why a pack that weighed only 3-5oz couldn't have a tear weight strength of 50lbs+. This is useful not just for backpacks, but of course tents as well. The bottom line is pack weights under 10lbs - what once used to be considered minimalist - will become standardized as the average for a safe and comfortable trip for the average BPer. A 20 degree bag, secure dry tent, warm jacket & strong pack might come in at 5lbs.

Re: Future Of Backpacks

Posted: Fri Dec 01, 2017 2:46 pm
by Hobbes
I should add that the key to both long distance running & hiking is using muscles to pre-load the release cycle. Sort of like how Formula 1 uses kinetic energy from braking to recharge batteries that are used for peripheral actions, proper form allows your legs, hips, back to compress and then unload on the upswing.

This effort is obviously compromised by a heavy pack, which is why the constant drive in lighter packs is also leading to distance records repeatedly falling. If you follow FKT, you can observe that times are being eclipsed over & over again on a 6-12 month cycle. What seemed incredible last year is shattered by a new record.

All this is based on the science of human propulsion (form, training & conditioning), combined with materials science. You don't have to be an elite, top flight athlete to benefit from these trends. You can be just a regular Joe/Jane out for a stroll through the Sierra. 100 years ago, Sierra club outings had vast mule trains to carry everyone's gear. People walked freely.

For some reason, maybe Norman Clyde, maybe the growth of working class leisure time, but the concept of a distinguished SF professional being free to explore, think & write became overshadowed by a macho-man, "I'm stronger than a mule" kind of mindset. Thankfully, that seems to be ending with the last generation hanging up their spurs. All the growth these days is being driven by these kind of super-stars:

http://www.palantepacks.com/

Re: Future Of Backpacks

Posted: Fri Dec 01, 2017 3:41 pm
by longri
Hobbes wrote:This effort is obviously compromised by a heavy pack, which is why the constant drive in lighter packs is also leading to distance records repeatedly falling. If you follow FKT, you can observe that times are being eclipsed over & over again on a 6-12 month cycle. What seemed incredible last year is shattered by a new record.
Pack weight minimization runs up against a serious obstacle on long trips where food weight dominates. Shaving the base pack weight is still important but has less of an impact than on shorter trips. If overall efficiency of movement could be improved, like the guy in the article suggested, it might reap large dividends. Maybe. Any effect would have a positive feedback since lower energy requirements would allow one to reduce food weight.

For shorter trips? A 5lb bag+tent+jacket+pack for summer isn't hard to do with yesterday's off the shelf gear. But 5lbs of food for a two week trip isn't even on the horizon.

Maybe a wheel on the pack? I've seen those on nicely groomed trails.