Is your desk/workstation set up as ergonomically as possible?
do you hold the phone with neck/shoulder quite often?
how many hr s a day do you do computer work, do you often take breaks to stretch and get blood flowing again...?
How is your overall posture - head forward , shoulders hunched or rolled forward of the body?
TOS can also be related to repetitive work and static postures (desk-work) over time.

Here's our useful sticky thread link for our TOS forum - like a crash course for TOS -
http://neurotalk.psychcentral.com/thread84.html