I found this lumbar roll the other day, and think that it's worth sharing; being of a good price (£15), size, not too firm (so it's comfortable!), and pretty well made.

Lumbar roll in Original 'Elite'

Most people think of a lumbar roll supporting the arch in the back when they are seating at a PC or driving.... that it does, but having your low back in a good posture has a direct effect on your mid-back, neck and shoulder postures.  So can help prevent/ relieve postural related pains from these area (ie. your upper trapezius muscles becoming tight and overactive)

Try it and see before you buy.... Make a homemade lumbar roll with a hand towel rolled up in one leg of a pair of tights (and use the other leg to tie it around your chair).  The lumbar roll should be positioned in the small of your back (around waist level), with your bottom tucked in under it.

 If you feel less stiff and achy in any part of your spine, then a lumbar roll may help you too.