When a patient gets up from sitting position which of the following events takes place in his knee joint?
Medial rotation of femur on a fixed tibia
Lateral rotation of femur on a fixed tibia
Medial rotation of tibia on a fixed femur
Lateral rotation of tibia on a fixed femur
Physiological locking occurs in extension when the femur is internally (medially) rotated on a fixed tibia.
Locking is a mechanism that allows the knee to remain in the position of full extension as in standing without much muscular efforts and is caused by quadriceps femoris.