THE ARTICULAR TRAVEL OF THE KNEE

The knee is a personal anthropometrical feature, its travel is determined:

- by the length of the cruciate ligaments
- by every single point of intersection

Its articular travel can be determined by an instrument with two scales of measurement:

- an angular scale, for the degree of bending,
- a linear scale, for the re-entry of the foot.

THE KNEE EQUATION

This is determined by studying the trajectory travel of the leg, verified by the Right re-entry of the leg, with respect to the centre of the machine, at different angles of bending.

In a system (x,y) with the origin at the centre of the knee, initially the trajectory of the leg is an arc of circumference.
Subsequently, to determine the actual trajectory, the translation of the system (x,y) along the axis X1 of a new orthogonal system (X1,Y1) has to be considered.
By substituting the new coordinates obtained from the translation formulas in the equation of the circumference, you obtain the equation.