The knee is an example of a _______________ joint.

The knee is classified as a pivotal hinge joint primarily due to its structure and movement capabilities. This type of joint allows for flexion and extension, which are the primary actions at the knee. It also facilitates a small degree of rotation, especially when the knee is flexed.

The knee's anatomy, with its complex arrangement of ligaments and menisci, supports this pivotal movement, enabling the joint to maintain stability while allowing the necessary range of motion required for activities such as walking, running, and jumping. Therefore, the pivotal hinge classification accurately reflects the knee's functional mechanics.

A pivotal hinge joint is characterized by its primary motion being a swinging or rotating movement around a single axis—allowing flexion and extension—while the rotational component, although limited, is essential for the joint's overall functionality. Recognizing the knee in this light helps in understanding its biomechanics and the importance of stability and mobility in human movement.