Chiropractic was founded on the concept of tone in 1895. Current research continues to support and advance the concept of the tonal model. Tone is the normal degree of nerve tension. To understand this model, think of the strings on a guitar. The strings are attached to the guitar at each end and then tightened until they are "in tune." A perfectly tuned guitar can make beautiful music. A guitar with too much or too little tension on the strings makes less than beautiful music. In a way, Tonal Chiropractic seeks to tune the spine and nervous system. Too much or too little tension in the nervous system decreases the body's ability to adapt. When Optimal Neurospinal Tone is present, the body has a better opportunity to heal, advance, and reorganize.