Many headaches occur as the result of dysfunction in the neck (or cervical spine). Doctors will often refer to headaches as “cervico-genic”, as in “from the neck” or tension-type headaches, relating to stress. In reality even tension headaches can originate from the neck because, when we are stressed, we often raise our shoulders, using the upper trapezius and levator scapulae muscles. These muscles attach into the upper part of the neck and, if tight will cause restriction in the upper cervical spine vertebrae, resulting in headaches. A huge number of both cervicogenic and tension-type headaches can be prevented with diligent commitment to improving overall posture, particularly whilst sitting.
The human head is similar in weight to a standard 14lb ten-pin bowling ball. If you imagine placing this bowling ball on a 15cm long broom handle you have created a model which fairly accurately represents the head and neck complex.
If you hold the stick vertically the bowling ball will be heavy but relatively easily supported by the muscles in your arms. If you tilt the stick forwards of this vertical line (e.g. by 15 degrees) the bowling ball will feel heavier and there will be considerably more strain placed on the arm muscles to support the load. This apparent increase in load is the result of gravity acting on the mass of the ball, tending to push it over onto the floor. When the stick is vertical, the force of gravity acting on the mass of the ball is somewhat supported by the stick itself, making it easier to support.
By applying the same basic principles of physics to the head and neck it should be easy to understand that if you position your head forward of the vertical line of gravity you will be increasing the load on the neck muscles in order to “hold” your head on. In most cases the neck muscles alone cannot generate enough force to hold the weight of the head in this forward (“protracted”) position, and the shoulder muscles (which also attach into the bones of the neck) are automatically recruited to support the load.
Over a period of time these muscles get over-worked and irritated because they are designed to work intermittently to move the shoulder/arm complex and they have been recruited “full-time” to support the head.