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We had a question over on History.SE about why "hobo"s used to carry bindles (as shown in this picture from around the beginning of the 20th Century)

enter image description here

I wrote up an answer based on what seemed to me to be a pretty clear physical advantage of using a lever to help with the effort of dealing with that weight all day.

Lever image balancing 100kg with 5kg

However, I haven't taken physics in about 3 decades, and don't use it that much in my day job, so I'm a little shaky on the details of exactly how it helps. That of course caused a long comment thread. I'd like to get that right, at least in high-level digest form.

So from a physics standpoint of forces and weights, what exactly are the advantages and tradeoffs of using this kind of lever to help carry a load around all day? Perhaps compared to either carrying the same load balanced right on the body (fulcrum), or slung over the shoulder without any help from the stick (lever). Assume the weights used in the picture above (which I know are way off for a historical bindle, but have the advantage of being nice round numbers).

I'm thinking particularly in terms of the effort that has to be put out continually by the arm to counterweight the load, and the legs (the fulcrum) to hold the load up. I wouldn't be shocked if there are other physical factors I'm missing too.

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  • $\begingroup$ I expect the main advantage is that it is cheap to construct. Consider what are the forces on the fulcrum in your lever image. $\endgroup$
    – The Photon
    Commented May 20, 2020 at 19:13
  • $\begingroup$ @ThePhoton - I agree with that compared to say a backpack. But of course not using the stick (which is the other two options I mentioned in this question) isn't any more expensive than using it. $\endgroup$
    – T.E.D.
    Commented May 20, 2020 at 19:16
  • $\begingroup$ Think about carrying a sack of groceries as you walk. You're constantly working to keep the sack from interfering with the motion of your legs. Overall I think this is more a question of kinesiology than physics. $\endgroup$
    – The Photon
    Commented May 20, 2020 at 19:25
  • $\begingroup$ I'll consider that. Neither of the other options I listed in the question would interfere with the legs either. I suppose that if I'm wrong that there's a physics advantage, that's an answer. $\endgroup$
    – T.E.D.
    Commented May 20, 2020 at 19:26
  • $\begingroup$ Thank you for the tag edit @Qmechanic. I was certain it needed to be tagged better, but I don't know this site well enough yet to know what to use. $\endgroup$
    – T.E.D.
    Commented May 20, 2020 at 20:01

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The main advantage would not be that the person would have to exert less force: they have to exert the same force to keep it from falling to the ground whether it is in a bindle or held in their hand. The advantage comes from what muscles are supporting the weight. Finger muscles are relatively weak, so a load being held by a hand will feel harder to support than a load being held by a shoulder (which is why wearing a backpack feels easier than holding the same backpack in your hand). As for the force on the pole, that would be the weight of the arm. This gives the owner a place to rest their arm as they are walking, as well as providing a way to balance the bindle.

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