To properly evaluate residual permanent disability arising from impairment of the spine, it is essential to conduct a careful and complete examination in order to arrive at a diagnosis and a determination that present findings are unlikely to change. A formula for computation of permanent disability as developed by McBride includes functional deficiency and physical disorders, taking into account 12 variables. This formula can be simplified to seven components if the physical disorders are mentally computed into the factors of quickness of action, coordination, strength, security, endurance, safety, and adverse employability, which are given weighted values. This method can provide a valid determination of percentage of disability. Some situations only require a delineation of the impairment present and defer disability determination to an agency or board. Currently, there is a trend toward equating the amount of disability with the loss of earnings, which is quite contrary to the longstanding, traditional view.