DBF may have a huge point, Char. Many of my clients at work were major office furniture companies and we did a lot of kinesiology and ergonomic studies with them.
Your chair at work may be in a conspiracy with your work station to cause you multiple points of discomfort. Things to be aware of are things like the height of the chair for your legs, can your feet rest flat without putting pressure on your thighs or lower back? Is your desk/work area too high for your arms to rest at their natural level? Must you look up/down to view your computer monitor? Is your keyboard in a tray below your desktop or must you raise your arms to the keyboard? Do you habitually type while resting your arms' weight onto your wrists? Can your chair rock, roll, and swivel to accommodate your routine motions during regular tasks?
If your work station can't work in concert with your natural body motions, it's almost inevitable that the theory has merit. Naturally, job stress is real and can contribute, but if the physical conditions have a negative impact, it can really effect your comfort.
I hope you'll feel better soon.