i want to get a messenger bag and after reading this article it showed me what i have to be awaire of and what i dont.i now know that messenger bags can be harmful, but only if you dont use them correctly.i think im goin to get the messenger bag i want but also keep a regular book bag handy.
tahnks lots!

David, I'm sorry, you have no idea what you're talking about. Messenger bags were created for....ding ding ding, messengers. They were never purses. They're meant to be for riding bikes, primarily. Most backpacks are not designed for use while bent over on the handlebars. Messenger bags allow you to carry the weight high up on your back, which is the best place on a bike. It is unfortunate, however, that most cheap messenger bags designed for schoolkids can't really be worn this way. Like the article says, they get worn low, near the hip, rather than high on the back and strapped down tightly. Take a look at chromebags.com, which specializes in professional bike messenger bags.
If you're going to ride a bike more than you walk, wear a properly designed messenger bag. If you're going to walk, take a backpack or...*gulp* "rolling bookbag"...
It's always about how people use these products, not simply the products in a vacuum.

I've used a backpack my whole life up until this year. I used a messenger bag this past year, and I'm sad (now) to say I used it the wrong way (with the strap not crossing my back, but just hanging on the right shoulder). It made my right shoulder really tense and not as flexible as the other one. It also gave the right shoulder more muscle, but now my shoulders just feel uneven. It's weird, and I'm switching back to a normal backpack next year.
P.S. wheely backpacks can be a HUGE nuisance in school settings (especially at schools like mine with stairs), being that they get in everyone's way and crowd up halls

I have used one for several years cycling and it is now my "regular" pack as well. They are designed for cycle messengers. You don't have to be a messenger to use one, but for pete's sake they aren't designed for walking around per se anymore than mountainbike shoes are designed for ballroom dancing. You don't see people trying to do the tango in bike shoes and complaining the cleats hurt their feet. Folks gotta stop co-opting what's functional and making it a fashion statement. I'm all for messenger bags -- tho was a time when if you saw someone with it you knew they are or were a rider, which kinda helped. Now it could just be some dude taking the train, ok, it's a free country but it amazes me how people misuse products and then get some doctor to say oh, yeh, they are unsafe, avoid them. If worn improperly anything is unsafe. Also different bags fit differently; upon trying a different messenger bag with a different thickness strap I got neck pain. Adjusted it for the difference. No more pain. Common sense folks. That, and get a bike if you're going to get a messenger bag.