Hi Ryan - with a sitting job you might try changing postures significantly every 30min or so. This means go from upright 'proper' posture to slouching to leaning forward to standing (if you have that option). Alternatively sitting on a ball or wobble disc gives you the option of shifting around frequently. Our bodies like to move frequently and avoid static positions. On the other hand you have a trade job where you are on your feet, moving, lifting, etc, all day. Nothing wrong with that as long as you prepare yourself physically for stresses that might be new to your body. I've treated workers with low back pain from digging trenches, shoulder pain from working overhead or reaching into awkward positions etc. If you approach this type of job like a elite sporting event and train your body for the specific tasks required then you should be ok until retirement. Just work smart and build a tolerance for the work and your body will adapt. Good luck!