I bought this bag to replace the Ameribag I had purchased the year before. The Ameribag is advertised as being ergonomic, but I found that, being designed to be worn on one shoulder, it made my opposite shoulder rise to compensate for the weight of the bag. Over time, it caused me to walk crookedly, creating problems for my back. I decided to try the Baggalini Messenger Bagg so that I could sling it over one shoulder, but put the bulk of the bag in the front. My back pains have subsided, and I am walking much straighter now.