Which of the following movements are primarily possible at the knee joint?

The primary movements that occur at the knee joint are extension and flexion. The knee is a hinge joint, which means it mainly allows movement in one plane—forward and backward. When the knee flexes, it decreases the angle between the thigh and the lower leg, typically when performing actions like sitting or squatting. Conversely, extension increases this angle, as observed when standing up or straightening the leg.

While there are minor rotational movements at the knee that can occur when the joint is flexed, these are not the primary functions of the knee joint. Adduction and abduction, movements associated with the side-to-side shifting of joints, are not significant actions performed at the knee either, as they primarily occur in joints like the shoulder or hip. Therefore, the emphasis on extension and flexion as the primary movements of the knee demonstrates the functional mechanics of this joint effectively.