The diagonals are muscle structures that hold and moves our body. In this article (part one) we explore the development of these diagonals from childhood and the enhancement of them in professional athletes Part two will then explore what happens when neurological diseases damage these muscle pattern. Neurological disease will affect how the diagonals work more than orthopedic diseases, due to its dependency on structures within the brain. Although these parts of the brain are not yet identified the innervation of the spine and the large joints give us a clear picture that one hemisphere controls both parts. The overall distribution is unequal (between 90%-10%) but this amount of variation in the distribution is what enables the diagonals to work in this way.