[The roll-glide value as a motion parameter of biological curved joints exemplified by the human knee joint]

By means of the so-called roll-gliding number lambda complex motion patterns between the moving parts of biological joints can easily be described as to being composed either of a more rolling motion with only minor wear or of a more gliding motion with a higher amount of wear at the joint surfaces. Thus the roll-gliding number, the magnitude of which depends on the angle of joint flexion, offers also an indirect approach to evaluate dynamic disorders of the function of such joints. As an example a description is given of the numerical calculation of the roll-gliding number for the medial and the lateral half of the human knee joint a various angles of joint flexion.