Restoring natural movement to the traumatized knee

The knee, with its bending-stretching movement, performs a rotational-translatory motion, described in mathematical terms by the “knee equation”:

X²+y²-2x₀x+x₀²-r²=0

After a trauma, this natural movement can become compromised.
During a course of post-traumatic rehabilitation it is important to respect the correct trajectory of the articulation motion in order not to force the articulation in an unnatural direction (Insall 1986) further compromising the organs responsible for regular physiological functioning.