An interesting article on the impact of using hipbelts.

[bjc]

https://www.outsideonline.com/2251986/surprising-science-backpacking?utm_medium=social&utm_source=facebook&utm_campaign=onsiteshare

[Greg Mihalik]

“The key point about walking, from a physics perspective, is that you don’t perform any overall mechanical work if you’re traveling at a steady speed over level ground. You have the same amount of kinetic and potential energy at the start of a hike as you do at the end—which means that, despite how you may feel, you haven’t done any net work, since work is the change in energy. That still holds true if you strap on a pack, Donelan points out: “In theory, you can make the extra weight ‘disappear,’ because you don’t need to do any net mechanical work on it.””

Pseudo-science at it’s worst. If Hutchinson had read the link referenced in the article he might have had a chance.

Outside Magazine – I’ll pass, thank you.

[jscott]

So if I change the definition of ‘work’ can I stay home and play music and still get paid?

[Lester Moore]

The article made an interesting point about the most efficient way for the human body to carry weight:

Where is the most efficient place to position a load? Believe it or not, it’s on your head.

Anyone who has portaged a canoe both with and without a tumpline can confirm this. So would it be useful to incorporate a head load carrying system into one’s backpacking kit? Maybe a structured hat with water bottle holders or gear pockets on the sides and top? Combined with a fast pack style backpack, it would provide a high degree of weight distribution over the body. Whether the added cost, weight and complexity would be worth it is debatable.

[bjc]

Somehow I knew this would trigger some interesting comments.  I’m just trying to make all that weight disappear! It’s not working.

[Lester Moore]

I’m just trying to make all that weight disappear!

The best way is to not carry all that weight to begin with, which is why we’re all here on BPL :-) There have been recent threads about hip belts versus no belt, and carrying more weight on the shoulder straps versus the backpack. But very little has been discussed about “using your head” while backpacking, for more than just thinking. Tumplines for canoes and canoe packs have been around a very long time. But why not put that useless head to work while backpacking? Could the head be a better place to carry a bear canister, a big water haul, or maybe just the day’s food and necessities?

[Gunnar H]

They could express it better but it is of cause not fundamentally wrong saying that transporting something horizontally at constant velocity doesn’t require work if you neglect friction. Its just that it is not the way it works when we walk, specially not with a loaded backpack. A pulk is much better keeping a load level than a backpack, and even though you get more weight and friction it is less effort using a pulk than a backpack – at least as long as its not uphill.

[Bob Moulder]

Yes, at least read the linked study’s abstract… the remainder quantifies the bloody obvious.  ;^/

 

 

[Greg Mihalik]

From Gunnar –  “… it is of [course] not fundamentally wrong saying that transporting something horizontally at constant velocity doesn’t require work if you neglect friction.”

Hutchinson is not talking about momentum (in a micro-gravity vacuum). He is talking about “… traveling at a steady speed over level ground.”

Even in space, work is performed to get something moving forward, and force is required to counteract gravity or change direction.

Walking across a level parking lot requires exerting a force in the direction of travel. (And a force to counteract gravity.)

 

[David Thomas]

All those little ups and downs do add up.  Otherwise, moving just our own bodies would take no energy either, but my weight-loss app and thousands of miles of experience indicate that I burn 100 calories to hike a level mile.  And I burn even more calories while carrying a load.

[Todd T]

Nobody I know uses a hip belt to minimize energy consumption.  They use it to take weight off their shoulders.

Nobody I know calls it a hip strap.

 

[Edgar H]

About tump lines,  when I carry too much weight,  I’ve found it useful to tie short cords to the top of the pack frame,  or along the shoulder strap anchor points,  and use them to tie a sheetbend to a thin towel or strip of fabric on both ends.

After getting the length adjusted,  the fabric can be flipped back out of the way across the top of the pack,  and retrieved to use as a tump line for a little while,  then flipped back out of the way again.

[Geoff Caplan]

Where is the most efficient place to position a load? Believe it or not, it’s on your head.

This is true, but not very practical in the hills. So it became the starting point for the Aarn bodypack concept, where placing some of the load in the front pockets helps counterbalance the load at the back. With the bodypack system almost all the load is transferred to the hip belt, with the shoulder straps performing a minor role in balancing the pack.

As a result, the walker can maintain an ergonomically upright posture, rather than having to lean forwards to balance the load to the rear. Work in a respected ergonomics lab has shown that this is significantly more efficient once loads become non-trivial.

 

[Matt Dirksen]

I’d be very curious on what they “figure out”. There seem to be lots and lots of variables which I hope they can consider, before rendering some opinions.

One thing I used to observe in my days of wearing heavy packs, was a noticeable loss of agility when I wore my belt more around my hips and not higher up – around my waist. Of course a few hours of 50+ lbs concentrated on the top of my lumbar, and it was time to slide the pack down a little, adding a little bit of constriction to the front of my thighs. But that extra “agility” made either scrambling or going on a steep decline a lot easier for me, so it seemed.

And of course, I suspect that my use of trekking poles “shifts” my center of gravity forward enough to change the equation as well.

On that note, has anyone ever thought about nudging some ounces onto the tops of trekking poles? A water bottle holster?  Zpacks snack bag pockets? Too much movement? Too wobbly?

In the BPL world, shifting a little weight there could be a measurable percent of one’s load.

Could make for some cool punching gloves, too!

[James Marco]

Nowhere does he mention the physical effort needed to maintain a load on your shoulders and/or head vs transferring that load, or a good portion of it, to your hips. To me, it is relatively obvious that the more muscles you have involved carrying a 40 pound load, the more energy it will take to carry that load over equal distances/elevation changes.

1) Walking with a load of any sort always involves your feet, legs and hips. You always expend energy to move.
2) Adding a 40 pound weight, your backpack packed for a couple weeks, adds 40lbs to your feet legs and hips regardless of how you walk, or where you are going. (Yes, I am ignoring hiking staffs.)

How we carry 40lbs is the question: Mostly on the shoulders? Mostly on the Hips?
If we use a shoulder harness alone, about 35lbs runs across your shoulders, down your back, and, to your hips. The other 5 lbs is absorbed by the rest of your body to transfer to your hips.
If you use a hip belt, 25 pounds is transferred directly to your hips, about 10 pounds is on your shoulders and back and 5lbs is transferred via other parts of your body.

Soo, my question is, how can moving 10 pounds on your shoulders be the same as moving 35lbs? Sorry, it just doesn’t make sense to me, regardless of how you tension your hip belt or shoulder harness or distribute your load.

Aarn packs work well, but I cannot use them. Unless I am carrying well over 50 pounds, they are just in the way more than they help. I *never* carry that much. My maximum load is around 27 pounds for about three weeks out. Maybe if I hunted, I would use them, the concept is sound (I also have an old cervical spine injury.) It is just over-kill for thru hikes and longer outings, generally. It is the rare person who can get out for longer than three weeks.

[Geoff Caplan]

Well, the ergonomic benefits of the Aarn pack kick in at well under 20 lbs – eg the benefits outweigh the additional weight of the front pockets. So in terms of efficiency you don’t need to be anywhere near 50 lbs before the bodypack makes sense.

Obviously, if you don’t like the front pockets for some reason that’s another issue. Personally I’ve go used to them, and like having everything easily to hand.

But in terms of pure ergonomics my experience with the pack leaves no doubt at all that it saves energy and saves wear and tear on the neck, spine and shoulders. For me it was a new experience to be carrying a week of food on a tough alpine trail and to walk from dawn to dusk without a single ache or pain…

[S. Steele]

If you carry less than 20 pounds or so then you don’t need a hip belt. Your shoulders are fine with such a reduced load. If you place your heaviest items in the center of your backpack and your lightest either side thereof you will reduce side to side swaying. Side to side swaying reduces your bio-mechanical efficiency, reducing your energy and potential speed. If you provide a hose and bite valve to your water bottle then you can have on the go water without having to stop – taking off your pack, access your water, return the bottle and put your pack back on. Just another waste of energy.

[Bob Moulder]

Thanks, but I’ll continue using my hip belts. I prefer them even on small day packs.

I have 3 different models of Zpacks packs and I can easily access water bottles while hiking and return them to their pockets without breaking stride, as well as food, map, compass, camera, etc.

[James Marco]

Well, I agree 100% with Bob. Hip belts for less than ten pounds are optional (say an SUL pack with 3 nights of food.) For 10 to 20 pounds, I just use a strap instead of a full hip belt, and have been known to use a strap up to 25 pounds. At 20-30 pounds a hip belt is more than worth it. But, I ALWAYS use a hip belt of some sort except when I am riding my bike.

“If you provide a hose and bite valve to your water bottle then you can have on the go water without having to stop – taking off your pack, access your water, return the bottle and put your pack back on. Just another waste of energy.”
I don’t normally take my pack off unless I stop for a snack. I just keep my water in my side pouch where I can reach behind me as I hike… Hosing, and bite valve are simply excess weight, and, fiddly to use, clean and carry.

I would guess our trails are much more difficult to traverse if you don’t need a hip belt. Hopping rocks across streams, up/down mountains, up & over blow downs, bushwhacking around beaver flooded areas, etc. are typical examples of a week long outing through the ADK’s. I NEED a hip belt everywhere I hike, rather than risk a broken leg or worse.

[S. Steele]

” I just keep my water in my side pouch where I can reach behind me as I hike… Hosing, and bite valve are simply excess weight, and, fiddly to use, clean and carry.”

Marco, both you and Moulder place your water bottles on the sides of your packs. It is no surprise to me that you guys need a strap or hip belt for loads less than or greater than 20 pounds. You have placed the normally heaviest item carried in or on a backpack at its’ outer extremity which generates thrusting necessitating a belt. You’re generating waste energy with such thrusting as well as increasing fatigue and yes your potential speed if you have any interest in it. Additionally, the water bottle costing about $1.50 is as easy to clean or replace the water bottle(s) your currently using. The hose and bite valve weigh a mere 1-1/2 ounces, a cheap price to pay for its’ convenience.

[Ken Thompson]

“Additionally, the water bottle costing about $1.50 is as easy to clean or replace the water bottle(s) your currently using.” ?

“The hose and bite valve weigh a mere 1-1/2 ounces, a cheap price to pay for its’ convenience.”

Evernew 2l bottle, 1.5oz

2l Source Outdoor bladder with insulated hose 6.2oz

Bottle is easier to deal with. More thirst quenching than sucking out of a tube. For me. Some water in a side pocket, .5l on shoulder strap. Never noticed this thrusting you keep bringing up.

Easy trail, loads under 25pounds, no hipbelt. Off trail or heavier loads, hipbelt. For me.

[James Marco]

Thrusting? Not sure what you mean. My heaviest item is my drybag containing my quilt, long johns, sleeping socks, and down sweater…around 46-60oz depending on the “weight” of my socks/long johns (UL, midweight, or both) around 2#12 to 3#12. The next heaviest is my food bag/bear bag, when I start around 12-15# for two weeks. My tarp, pot, stakes, stove, ditty bag go around 2#. My Pack goes about 25oz including my NightLite pad. “A pint’s a pound”. I only carry 2-500ml water bottles, or around 2#6oz. The heaviest items ARE in my pack. This all fits in an old Miniposa or Murmur. In fact, even the water bottles somewhat rest against my back, since both are narrow pack bodies at around 11″ wide.

I don’t see where “thrusting” comes in, except for hopping/jumping. Your hips move in a relatively smooth figure “8” while hiking/walking. Even hopping, most load is taken up by your feet/legs/knees/hips/hip belt before it reaches your spine/shoulders and jarring them. With a hip belt, the pack becomes a part of your body removing large jumping impacts form your spine and allowing you to push off with your toes/feet/legs smoothly while walking. Any residual side vectors are usually relatively smooth by the time they show up in my pack and follow the circular motion of my hips as I maintain my side to side balance. These result in some losses, but are more the result of the act of walking with or without a pack. Not much to do about it. Is this what you mean? Again, a hip belt takes these all up locking things evenly onto your body without hindering these motions, usually taken up by your buttock and thighs.

[Bob Moulder]

I use Gatorade bottles retrieved from the trash can at my local dog park. Every couple of years I return to the trash can to get some more, if necessary.

Although, to be honest, cost in this range is not an issue; if REI were the only source and they cost $8 apiece I’d probably get them there.

I’m also not a bladder person. I also don’t like the tube, although I have friends who use nifty little MYOG rigs using Smartwater bottles and they fit their needs perfectly. I use bladders with hose and bite valves when riding the mountain bike, but that is only out of necessity… mud on bottle caps is a problem.

I’d love to see a link to a study that validates this “thrusting” issue you keep mentioning, and not that very poorly conducted treadmill test discussed elsewhere.

[Jerry Adams]

“I use Gatorade bottles retrieved from the trash can at my local dog park. Every couple of years I return to the trash can to get some more, if necessary.”

You’re my hero, possibly more of a cheapskate than me : )

I carry my water bottle inside my pack, keeps it cool or warm.  It doesn’t bother me to stop every hour or so to take off pack, stretch, get a drink, grab a bite to eat.  There is no reason to drink more often than this.  Except maybe if you’re running or in hot temps.

I can see how bottle in side pocket would be worse in that it’s further from center.  Flops around a little as you walk along.  Coming up blank on a joke about the word thrusting : )

Bladder with hose, bottle in side pocket, bottle inside pack – all good ideas which could be good for different people, the beauty of this site is there is a diversity of ideas to choose from.

[S. Steele]

J. Marco: Thrusting is the side to side motion your pack moves as you move. Your torso expends energy returning your pack back to the opposite direction that your torso initially sent it. By placing your heaviest item(s) in the center of your pack you reduce the side to side “thrusting”.

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