I wrote recently “School Lightens the Load” about how schoolchildren in Kansas were relieved from having to lug heavy books around school.
An article today in the Daily Mail highlights another vulnerable group of people, young men are carrying their offices on one shoulder, and not surprisingly are developing strain patterns that used to be commonest in schoolchildren. The fashion item called a “man bag” is basically a pouch with a shoulder strap and will carry a laptop plus a lot more.
When I was a lad I had a paper round and the shop provided me with a canvas “man bag” to carry the papers in. I soon found that the casual, bagstrap on one shoulder approach was painful. I tried putting the strap across my body but that pressed painfully on my collar bone unless I supported the weight of the bag with one hand. The only solution was to minimise the carry time and deliver the papers as quickly as possible. And that I suggest is why you always used to see paper boys running.
So if you must carry several kilos around with you my suggestions are to run more, so that you cut down the carry time, or more sensibly get a wheelie bag like the ones used by airline cabin crew.