| OBJECTIVES: To assess the validity, reproducibility and interpretation of the DynaPort KneeTest in a group of patients with osteoarthritis of the knee who are undergoing total knee replacement, and to improve the clinimetric qualities of this test by modification of the scoring method. METHODS: Eight Saturdays were organized in two hospitals as test days during the period April-September 2002. On these days, 94 patients who were either awaiting total knee replacement or who had undergone total knee replacement in the past 2 years performed the DynaPort KneeTest twice on the same day. In addition, 92 healthy controls performed the KneeTest once. The test consists of 29 activities, such as walking, climbing stairs and sitting down. During performance of the activities, several belts containing six accelerometers are worn around the body. Relevant movement features are extracted from the signals and summarized into 29 activity scores and a total Knee Score as a measure of the quality of movement of the patient. All tests were supervized by a physiotherapist. Patients were randomized to be assessed twice by the same physiotherapist, or by a different physiotherapist, to assess intra and inter-observer reliability. After each test, the physiotherapist was asked to rate the overall quality of movement of the patient on a 5-point Likert scale. Additional information on subjective physical functioning was obtained by means of self-administered questionnaires (SF-36 and WOMAC). An independent physiotherapist performed a physical examination and scored the Knee Society Function Score. Validity will be assessed by calculating the ability of the individual movement features to discriminate between patients and controls and by comparing the Knee Score to the other functional measures. Based on the discriminative ability and the reproducibility of the individual movement features, a selection of movement features will be made for inclusion in a modified Knee Score. Furthermore, the additional value of several newly extracted movement features will be assessed. A proposal will be made for a modified Knee Score. |
