As much as archery appeals to the Renaissance Festival attending, fantasy game playing, Lord of the Rings fan boy nerd within me it probably isn't the most effective thing to do to get rid of back pain, not to mention that archery isn't a very accessible hobby for most people due to needing somewhere to shoot.

Yoga, going for a jog or swim, doing pull ups on an exercise bar, or doing pretty much any exercise which involves getting up from the computer periodically and doing something with your upper body will help with back pain, and probably be much easier and more accessible.

Archery definitely does have that fun appeal though.