These are the first key indicators pro- viding information necessary to generate a hypothesis about the cause of the patient’s problem. If the tests are positive, the therapist would postu- late that cervical nerve roots are in- volved in the disease process, and these patients will be clustered together as one classification category. However, this clinical impression needs further testing before a treatment strategy can be decided. Usually, a category can be further branched into several patterns according to the responses to other key tests. Using this continuous reasoning process, other categories of similar clinical pictures can be identified. The decision making process and the characteristics of each category are described in Tables 1– 4 and Figures 1 and 2.