Fascia is a connective tissue in your body that surrounds and supports every single structure, including bone, organs, muscles, blood vessels and even individual cells. It runs from top of your head to the tip of your toes, in a 3-D web, literally providing the framework off which everything is contained, separated, supported and protected.
Fascia is tough yet pliable, but can become solidified and shortened through poor posture, trauma and inflammation. (Fascia has lots of nerve supply, but not as much blood supply, making it slower to heal, but more painful than some tissues when injured.)
This tightening and shortening in one area will pull on the rest of the fascial web, causing distortions and strain within the body, not to mention more pain and decreased range of motion.
To break it down on a smaller level, lets take a muscle. Fascia surrounds the muscle itself, separating it from other muscles near by. It also surrounds everything that makes up the muscle: every muscular fascicle, fibril, mycrofibril and cell within the muscle. If there is a restriction in one part of the fascia within this muscle, it will place tension and pressure on the entire muscle, causing it to work harder to contract and relax, leading to fatigue, and potentially more trauma.
The restrictions within this single muscle will cause tension on surrounding structures as well. Think of it like a pull in a knit sweater. If you tug on the pull, it will tighten the weave of the garment, causing scrunching and bunching not just at the pull site, but way up at distant spots also.
So sometimes your neck pain isn’t coming from your neck at all!