Pack Your Bags: Newsletter Challenge (October 2015)

putting heavier stuff close to my back and the lighter to the outer part is where I always used to put it and it worked great for me

I learned that you put the light stuff on the bottom and the heavy stuff to the top.

I forgot why!

I'm thinking along the lines that it is easier to balance a broomstick with the head at the top and impossible with it at the bottom. Now to apply it (or otherwise) to backpacks!!

with the head at the bottom i don't have to balance the broomstick - but i could balance on the broomstick with the head down!!

or put the seismometer ball/cylinder onto the writing needle!

Yes, it's easier to maintain your balance with a lower center of gravity.

Heavier item should be place in the center of the pack and as close to your back as possible. It will make the pack feel balanced. The heavy items closer to your back will be easier to carry as its closer to your center of balance. The heavy item at the bottom will cause it to sag away from the other items. At the top it would feel top heavy.

Weight is not the best way to decide only on an items placement. Sleeping gear is light. It's used once a day. Mess kit is heavy if at the bottm because it's heavy you have to pull everything out to get to it at lunch time. Now you have to repack it.

Good answer. That's one of the things I learned in the Scouts.

to lever out the world

I prefer to fill backpacks in order of what's crushable or not. Non crushable at the bottom crushable at the top.

I suggest the optimal packing scheme depends a lot on what you're packing and therefore is a combination of most suggestions already posed.

It actually depends on the terrain. You want to adjust the centre of gravity to make it easier on yourself if you are climbing steep hills or mountains for example.

Ideally your pack centre of gravity should be pulling you back a bit not weighing you down pushing you forward and putting more pressure on your leg joints.

_{Jack - Fell down one of our tallest mountains...twice.}

No. A backpack, however it is packed, has a centre of mass which is behind the spine. The human foot is not designed to support rearward rotational loads, so it is essential to bring the combined body and backpack centre of mass to lie over or in front of the ankle, by leaning forwards. The angle of lean is minimised by packing the heavy stuff at the top. The terrain has no influence on the angle.

Well I have to disagree here as I am an avid hiker and this is how I was trained and adjusting the pack centre of gravity depending on the angle of terrain does help in my personal experience, especially when carrying heavy pack loads (30% body weight) up steep terrain.

Perhaps a practical exercise is in order?

I suggest you draw a force diagram before you come up with any more of this "pack centre of gravity should be pulling you back a bit not weighing you down pushing you forward and putting more pressure on your leg joints" guff. Forgetting the pack for the moment, the act of walking requires that the body's centre of mass be translated forwards. This is achieved by leaning forwards to create a momentary imbalance. That lean angle results from flexing the hip and ankle joint, but the extensor muscles of the ankle are sufficient to counteract that imbalance while the other foot is lifted and brought forward to re-establish stability.
Now if you actually draw the force diagram you will note that the angle of the terrain to the horizontal has no influence whatever on the body's centre of mass. It is true that the range of ankle flexion is not unlimited, so that the full contact of the shoe sole is not possible on a steep upward slope, but that has nothing to do with the balancing forces.
I hope it should be clear by now that the last thing you want is for the pack to tip you backwards (unless you enjoy hiking backwards)

Here is a template to work with:

I would suggest that the monumental irrelevance of that post is made worse by the anatomical inexactitude of the diagrams. However good or bad the posture is, the centre of mass of the body projects downwards in front of the ankle joint when standing. The centre of mass of the backpack is always well behind the spine, and unless you lean forwards the tendency is for the combined centre of mass to project downwards behind the ankle joint, which is a completely unstable situation. As has been said several times already in this thread, the higher the centre of mass of the backpack, the less you have to lean forward to bring it in front of the ankle again.

At your suggestion, I have attempted to provide a more accurate depiction of a skeletal structure, common among lower primates lacking a developed sense of humor and yet, are able to articulate displeasure with "monumental irrelevance".

You're welcome to provide as many templates as you like, but that one couldn't hike far either.

Thank goodness hiking doesn't require us to stand straight at the Position of Attention for long periods of time unsupported... rather we're moving forward, taking strides, Rest Steps, Kick Steps, Side Skips, and any number of other Stride Techniques depending on the situation.

Not fully negating your position, but hiking - especially performance or endurance hiking is about rhythm and flow, and pacing, and breathing, and stride/step technique, and balance. Balance is control and of course as soon as you become stationary and stand straight up, you're stabilizing muscles are going to be in a constant battle to maintain both.

I couldn't agree more.

I would just make sure the pack had quick release straps in case of bears.

One does not have to out run the bear, just the bear food. If you wish to be included in the menu, stay with the food items in the pack. The bear does not care where the potato chips are relative to the steak in the pack (or outside the pack).

C.O.G. is less important in carrying a pack, than center of lateral loading. Thus, as others have remarkably and correctly concluded, the higher the mass is in loading position, the less far forward the back must bend in order to keep the load laterally centered on the center of support (the ankles and arch) of the foot). This is lesson one of ergonomics that even primitives figured out long ago.

Any time you carry any weight, whether in front or in back, the load needs to be centered laterally as near as possible (front to back, or back to front) to reduce back strain, and improve balance.

Besides, a frying pan is a better weapon against a bear than a bag of potato chips, unless one flings the bag at the bear, then swings the frying pan in the widest arch possible to maximize impact with the bears nose.

So the light stuff on the bottom and the heavy stuff on top but alternating!

The bottom should be a layer of Beer, then Ice on top of that, cold settles as heat rises. And then continue the process as previously stated.

I think this topic should fall on modelling category

Beast of burden- damn anytime any day would be a good as long as I have the model to carry it.

Or this, load evenly distributed

Pack racks distribute the weight over the lower lumbar region, transferring the load from the straps, so I suppose you would pack to simulate this.

Or, if by mistake, you grabbed your backpack to go skydiving, it would not matter much.

Wait, "Regular Hiker", is this a trick question?

I think you are on to something.

Hmmm, a regular hiker is going to need to access the TP. TP is one of the lighter items, and this hikers noted regularity will necessitate the TP being at the top/ easily accessed.

.

So weight distribution aside, yes, for a regular hiker, packing at least one of the light items at the top of the pack is a good idea.

Nah. For the regular hiker, the TP is kept in an aouter pocket - much easier access (and about half way down the pack height)

Good backpacks are set up to transfer the load to the hip belt and the lower suspension which contacts the lumbar region. You want your hip bones to carry the weight. The loads are roughly vertical. The shoulder straps should not carry much, if any of the vertical load. Those are there to provide steadying support to keep the pack from falling backwards or off to the sides. Put heavy loads on the shoulders and you will get a sore neck at the very least.

A sensible answer at last!

Is that a picture of the Brits quitting India?

Brits were still painting themselves blue when this happened.

Picture from a local newspaper at the time of Hannibal traveling light on his backpacking adventure.

The best way that I've found is to place a layer of soft things against the back with the heavier items close to the back and high. The idea is to keep the weight as close to being over the hips as possible. This places less strain on the back and is easiest to keep your balance. A pack with a waist belt is best. It both aids in support and keeps the load from slipping around.

You shouldn't pack heavy things in your pack. They should be on your belt. soft absorbable things should be placed close to your body because you will perspire where the pack is located, and it will help from getting a sore back.

Packing turtle.

Once, as a kid, I took everything out of my backpack so I could insert a 40 lb. alligator snapping turtle in head first.

We stopped and asked a farmer for a drink of water and the farmer noticed the pack moving. "What ya got in there?" he asked, I let the extremely frustrated turtle out, and the farmer jumped back. "Holy smokes", he exclaimed, and picking it up by it's tail (the only safe handle) put it on his weigh scale. 39.5 lb. The farmer said "You know, that turtle is probably 80 years old".

I thought about it, put the turtle back in the pack, and returned it to its home in the creek.

It all depends on the type of pack,internal frame,external frame, rucksack(no frame),waist belt or tump line. Each style has different characteristics so this challenge is devoid of enough intel to provide any satisfactory reply.

Not really a good question since there are different kinds of packs for different uses. Since I hike, I pack my backpack with the items I will need most of first at the top, snacks, granola bars, jacket, cap etc. and those things I might or rarely need at the bottom, camera tripod, blanket, first aid kit, underwear. :-). From my experience this is a common day hiker pack, no frame light padded straps. Usually no more than 10 pounds. Water bottles attached by carabiner to lower strap points.

That is a valid point, as the questions starts out with "You are a regular hiker." It doesn't mention camping or spending a week in the wilderness, so there isn't a need for a regular hiker to carry an abundance of unnecessary equipment along for a hike.

Doesn't matter if you just make Baldrick carry it.

I am not a beast of burden...

Finally, someone with ground pounding experience.

Oh yeah, and a lot of it. Outside of normal military activities, I've also done the Nijmegan March in full combat load 4 times, and hike regularly as a civilian.

Depends on whether you use a H pack or an A pack. The H pack sits high on your shoulders, going up behind the head, and the A pack hangs down nearer the waist. You have to bend forward to balance the load in both cases. Not good for the back. For A pack, heavy items at the top, so closer to shoulders and you don't have to bend so far forward to balance the load. For H pack, if heavy items at the top, the moment will send you A over T the first time you trip and try to rebalance. So heavy items in the bottom, nearer to the shoulders. Maybe even in the middle, so practically right on the shoulders, easy to balance, less bending forward. The biggest problem is the stress on the shoulders. I still have the swellings on the collarbones from this stress. Foam rubber was the best padding to spread the load on shoulders and waist.

looking at the question critically:
"regular hiker" means you have loaded backpacks regularly will know from experience

"you decide" implies you always do it this way from your first packing decision? or does it mean a one-off trial to see if there's a better way outside your experience

the two questions could be separate, but since we would need two challenges to answer ( or give reasons why ) , we would have to consider them forming 1 question from 2 different angles.

so while the answers that address unpacking logistics, or crushing of lighter objects at lower positions, the pose of "Is this scheme good for your body?" immediately discounts those.

so the questions are framed against long term health being the first instance, not hiking efficiency. Interesting answers about different styles of backpacks offer some insights but the challenge is put in broad terms, so the answer should encompass all the design variations.

Since the question didn't ask for reasons why, my answer would be simply "No", even before i read all the replies

the heavier parts press more than the lighter parts.

the heavier parts deform the lighter parts more than the lighter parts the heavier parts.

it is one way to pack the backpack!

I would pack the heavier items in the vertical center of the bag (so as to not throw off my balance) and on the horizontal plane I would pack the heavier items on the same horizontal level (it might not be effectively on the same height as the straps as I would extend the line that the axis of the hip-straps make and where this line intersects with the vertical line is where I would pack) as the hip-straps so that the larger weight would be transferred to the hips. Lastly I would try and pack as much of the heavier items as close to the shoulder straps as possible while still having a soft layer of maybe a t-shirt or jacket.

In practice, I pretty much just throw everything into my bag and hope it closes.

"The answer to this challenge will be posted later this month, right here on CR4."

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