Which bag is better for the back: two straps or one?

Korea was once one.  The northerners known for their love of backpacks and the southerners for their love of handbags. Alas, war soon ensued. Something else may have led to the slight disagreement between, the now, two countries, but I’m pretty sure it was this debate that did the bulk of the work.

As a physiotherapist I often advise patients with upper and mid back pain to opt for the double strapped bag. I am North Korea and they are the much prettier, yet superficial south. Until now, I’ve been basing this suggestion on common sense and a hunch, literally (said in female, teenage voice), rather than actual scientific evidence. That is until now.

Two straps or one?

The study I am am making reference to was conducted on 22 University students. The researchers hooked up electrodes to the muscles of the participants’ upper and mid backs to determine the activity of these muscles. It was found that wearing a one strap bag led to significantly greater activity of the upper trapezius (the big, triangular shoulder muscle) and  the upper erector spinae (the ropey long muscles that run next to the spine).  Increased muscle activity, means increased load. Increased load often means increased pain. So either this was a state funded project for Kim to push some mo’ propaganda, or it’s true.

Is it healthful?

Well, in a word, the study in question is junk. It’s on a very small number of individuals and muscle activity analysis is often inaccurate. Regardless, it makes sense and it’s better than nothing. If you have a strap on one shoulder, that shoulder bears the brunt of the weight. Therefore, based on weak evidence and common sense: two strap bags are slightly healthful, one strap bags are not.

I hope this has been healthful. Are you a one or two strapper ;)?