Never mind paper cuts or squeezing your paper cup of coffee too hard and covering your hand in red-hot Americano, pain in the Levator Scapulae is one of the 5 most common workplace injuries.
Set up your desk and chair correctly, carry your stuff in rucksack (use both straps) and you're sorted. If you're not sure how to do this - your friendly office FM will be able to help (the desk thing, not the rucksack thing, I'm assuming you get that part without needing an assistant).
Hanwell said straining the levator scapulae, found on the sides of the neck, was one of the most common injuries. The causes of straining this muscle include: the mouse being too far away; carrying a laptop bag; wedging a phone between your ear and shoulder; stress/tension; and a cold temperature, which causes hunching. Remedies include supporting arms on the desk while typing/mousing; avoiding wedging the phone between ear and shoulder; keeping shoulder bag weight to a minimum; and stretching the anterior (pectoral) muscles.