I am a firm believer in taking care of my body, even if I look strange doing it. For instance, for many years, my main purse was a large leather fanny pack. I tend to get alot of neck and upper back pain, and hanging a purse on my shoulder made it worse. Carrying the purse in my hand wasn't much better. The fanny pack was great. My hands were free to do other things, and the weight of my purse was supported by the muscles of my abdomen, lower back and legs, instead of my upper back and shoulder. It didn't exactly win me any fashion awards, but I didn't care.
I have a new purse now. Instead of a fanny pack, this one is a knapsack style, also leather. Actually, the straps zip together to form a regular strap, if I want to use it as a shoulder bag. Why would I want to, when this is so much more comfortable? Having the weight spread out over both shoulders, it seems like my purse is almost weightless. I still won't win any fashion awards, but I think it looks better than the fanny pack.
If you have problems with upper back, shoulder or neck pain, it may be caused or exacerbated by the way you carry your purse. Hanging a purse off of one shoulder puts alot of strain on the muscles of the neck and upper back. If you are like me, you go through your purse periodically and clean out the accumulated junk, but even the 'necessities' are heavy. Finding an alternative to carrying your purse on your shoulder can do wonders for how you feel. If you chose to keep your shoulder bag, try carrying it diagonally across your chest instead of hanging off of one shoulder. This spreads the weight over a larger area, and causes less strain.
About the fashion statement these purses make: I have said this before: What is more important- the opinion of people you have never seen before and may never see again, or taking care of the body you live in 24/7? Worried about what your friends/family/colleagues will think? If they say anything, explain why you are using the particular style of purse you chose. I have never gotten negative responses when I used the fanny pack, or now with the knapsack. In fact, I have had people ask me where I got them. Give one of these options a try. Your back and neck will thank you.