The kinematic magnetic resonance imaging technique has been developed to provide a functional examination of the knee.Technical limitations require this examination to be performed in supine position, and the knee motion is represented by anassembly of static positions at different knee angles. However, the main knee function is to support the body weight and performcontinuous motion, e.g. parallel squat. Our study quantified the knee kinematics of 20 healthy subjects in different motionconditions (finite and continuous) and in different mechanical conditions (continuous unloaded and continuous loaded). Weevaluated the angular and localisation difference of a finite helical axis of the knee motion for parallel squat, continuous kneeextension in supine position and the finite set of knee extension in supine position. We found large inter-individual dispersion. Themajority of subjects had equivalent knee kinematics between continuous knee extension and the finite set of knee extension in supineposition, but not between continuous knee extension in supine position and the parallel squat. Therefore, results from a functionalexamination of a finite set of knee extensions in supine position do not represent the knee motion in a parallel squat. Our resultssuggest that functional examination of the knee from magnetic resonance imaging do not necessarily reflect the physiologicalkinematics of the knee. Further investigation should focus on a new magnetic resonance imaging acquisition protocol that allowsimage acquisition during weight bearing or includes a special device which reproduces the loaded condition.
