Gesture standardization increases the reproducibility of 3D kinematic measurements of the knee joint.
BACKGROUND: The literature on the 3D kinematics of the knee suggests that the gesture accomplished during kinematic assessment might play a significant role in the values measured. The purpose of this study is to demonstrate that a standardized gesture leads to an increased reproducibility in 3D kinematic measurements of the knee. METHODS: Seventeen healthy male subjects performed series of knee-bends in standardized and unconstrained conditions while their left knee's 3D kinematics were recorded using an optical motion-recording system. Standardized knee-bends were performed in a specially designed structure stabilizing the shoulders, pelvis and feet. Coefficient of multiple correlation were calculated for the ascent and the descent phases of the knee-bends for the tibial rotation and abduction/adduction components of the knee movement. FINDINGS: Comparisons between coefficient of multiple correlation of the different gesture conditions showed a statistically significant increase in reproducibility for the tibial rotation during the standardized knee-bends. INTERPRETATION: It appears that gesture standardization is an interesting option to consider for precise kinematic assessment of the living human knee.