A method of performing an objective functional evaluation of a person's physical capacity comprises of a computer program particularly designed to amass and assess test data in accordance with a selected standard. A wide variety of evaluation protocols are incorporated to lead an operator in a step-by-step process. The method includes special testing tools, many of which have been modified to input data directly into the computer diagnostic program. The interface may be a wired or a wireless connection. The software program may use an algorithm to calculate a coefficient of variation for the multiple trials of a test, using the entered data, to providing a determination of validity of the trials. A second algorithm calculates an average result of the condition-specific protocol of tests, after which the software program correlates those average results to a database of normative standards to compute an impairment rating.