[Knee kinematics in flexion and extension using an electrogoniometric device: results in nine healthy subjects]. / Etude cinématique de la flexion-extension du genou à l'aide d'électrogoniomètre.

PURPOSE OF THE STUDY: We wanted to develop a gait evaluation protocol using an electrogoniometric device allowing simpler measurements than optoelectronic recordings. MATERIAL AND METHODS: Gait was studied in a group of nine healthy subjects, mean age 58 years, walking on flat ground at three different speeds. We recorded the knee flexion and extension angles and the main temporospatial gait parameters. The principal conditions required for considering gait to be normal were taken from the literature. RESULTS: The subjects exhibited gait cycles which were normal in 83% of the cases for both knees at all three walking speeds. In 17% of the cases, the subjects walked with a flexed knee or without flexion during the weight-bearing phase. Knee motion was symmetrical between the right and left knee in all subjects. Increased walking speed was associated with increases temporospatial parameters and greater flexion and extension angles, particularly during the weight-bearing phase. There was a correlation between the weight-bearing flexion phase and stride length. DISCUSSION: The walking distance was moderate but sufficient to avoid the influence of the start and stop cycles. The electrogoniometers were small and did not perturb walking. Certain temporospatial parameters could not be measured directly but could be estimated. We checked that the results corresponded with data in the literature. Lateralization (right, left dominance) did not influence knee movement. Flexion during weight-bearing could influence gait quality by affecting the balance between gravity and quadriceps muscle force, particularly when considering forces used to progress forward. Knee motion varies with walking speed and depends not only on overall knee motion measured without weight bearing, but probably also on the interaction between joint kinematics, the musculoligamentary system, and the locomotor schema.