Unless you have recently had back surgery, it is important that you try to avoid wearing back braces. There is no medical evidence proving that it helps back conditions or pain. In fact, recent studies suggest that it may aggravate certain back conditions and even cause the pain to worsen.
In order to prevent upper back pain, be sure that your arms are at a comfortable level when using the computer. Many back strains are caused by people extending and raising their arms too high or too low when they have to use the computer for prolonged periods of time.