The recent development of computer-assisted techniques for surgery, anterior cruciate ligament (ACL) reconstruction in particular, provides new ways of improving intraoperative kinematic evaluation and final functional outcome. In this paper we have tried to identify the optimal protocol for ACL evaluation, which can fully exploit the novel capability of electronic sensors and computer elaboration. In this work we statistically compared the main clinical tests that are used for knee evaluation and three different numerical methods for kinematic analysis. Results showed that only passive tests that investigate rotational and anteroposterior stability could discriminate ACL status and that the most effective protocol for computerized evaluation should be based on the Lachman and Drawer test, and forced internal-external rotations at full extension for pigs and 60 degrees, elaborated with the functional method (Martelli et al. Comput. Methods Programs Biomed. 62:77-86, 2000).