Noticed arms and back are giving you a hard time lately, especially towards the latter end of the week?
Have you been requiring the services of a masseuse more and more lately?
Ever connected it to your working conditions, specifically, on your work station? See, not all computer desks are created the same. There are some that are more ergonomically designed so that there is less strain on your body while you're working. Your computer may be positioned higher than usual and you haven't noticed that you actually have to crane your neck some upwards when you're working. Or the keyboard and mouse locations may also be too high or too low which causes strain on your arms and back.
Your chair may also be contributing to the problem.
So do check your work station. You may not need a total overhaul of office furniture. Sometimes, an unused telephone directory is all that it takes to adjust an errant monitor.