self-centering
The correspondence between the mechanical motion and the physiological one, creates a particularly important condition in practical use of such orthopedic devices that use the variable rotation center.
Based on the mechanical concept for which two bodoes bounded to each other propose a similar motion, in the movement tend to superimpose their trajectories, the device with variable center of rotation tends, during work, to superimpose its mechanical trajectory to the physiological one of the knee under the friction force that is created by the friction between the parts in contact.
It is the same frictional force which lets "slipping" the trajectory of the mechanical device on the physiological one up to disappear.
Based on the mechanical concept for which two bodoes bounded to each other propose a similar motion, in the movement tend to superimpose their trajectories, the device with variable center of rotation tends, during work, to superimpose its mechanical trajectory to the physiological one of the knee under the friction force that is created by the friction between the parts in contact.
It is the same frictional force which lets "slipping" the trajectory of the mechanical device on the physiological one up to disappear.