[New methods of analysis of gait in the evaluation of the action of anti-inflammatory drugs. Apropos of naproxen].

Two nontraumatizing and reproducible tools for quantitative gait analysis as part of the objective evaluation of nonsteroidal antiinflammatory drugs are reported. The Bessou gait analyzer is a simple mechanical device which measures spatiotemporal and kinematic parameters (stride length; duration of stride, weight-bearing, and forward swing; speed and peak speed of swing; and overall speed of walking). The ELITE system is a considerably more complex instrument for analyzing three-dimensional motions through high-speed shape recognition. Computerized data management allows not only to determine the spatiotemporal parameters listed above but also to study displacements of selected landmarks in several planes and to derive joint angles and angular speeds. Coupling of the ELITE system to a force platform and to telemetric transmission surface electromyography substantially expands the range of data provided. The mechanical gait analyzer was used to evaluate the effects of naproxen in 11 patients with osteoarthritis of the knee; another similar study in 13 patients with osteoarthritis of the hip is ongoing. Gait was recorded before and after daily administration of naproxen for seven days. After treatment, walking speed was significantly increased as a result of increased stride length and decreased stride duration. Durations of monopodal and bipodal weight-bearing decreased concomitantly with the increase in speed, whereas duration of forward swing remained unchanged. These data demonstrating improved kinematic gait parameters show that naproxen is effective in reducing the adverse mechanical effects of pain. This study also demonstrates the usefulness of gait analysis for evaluating drugs.