The smallest muscular activity requires that countless nerve impulses be sent to the muscle to be activated and to all of the adjoining and opposing muscles. For example, let us say that you want to flex your elbow. This requires that you must tighten the biceps and other associated muscles while simultaneously relaxing the triceps and other associated muscles. The combined nervous activity and muscular response must be precisely timed and exactly proportionate.

For more complex movements like rotating the head or taking a breath, the amount of coordinating activity increases exponentially. Unfortunately, the mechanism responsible for such coordination can break down and muscle fibers or whole muscles can actually lock in opposition to their normal activity.

Tonus System Dysfunction

When overused, muscles can lose their ability to understand how to relax. This is referred to as hypertonic. As a result, the muscles become overly tight. They tend to harbor myofascial trigger points, and cause stress on the muscles that oppose them and the joints that they cross.

Dermatomic and Spondylogenic Dysfunctions

If a nerve is pinched where it leaves the spine, or anywhere along its route, the area that nerve serves will feel pain. Many people have experienced such a problem with the sciatic nerve. It originates in the low back, but when pinched can make the knee, shin, or heel hurt. This is an example of dermatomic pain - literally translated - pain in an area of skin.

Spondylogenic Dysfunction

This occurs when the joints of the spine are compressed or otherwise impaired and cause their own special trigger point-type pain or dysfunction.