The determination of physical therapy treatment protocols, based on an in-home evaluation of a patient, is a complex task. The specific rules for treatment indications are individually simple, but numerous and hence time-consuming and prone to error using pencil-and-paper methods. This paper describes PTEVAL, a computerized Point-of-Care instrument designed to support the intervention protocols of an ongoing clinical trial. With appropriate modifications and extensions, PTEVAL can be a model for instruments used in clinical practice.