Which of the following does NOT have any movable joints?

The cranium is composed of several bones that are fused together and do not allow for movement, providing protection for the brain. This structure is a part of the skull, and its primary function is to support the head and safeguard the delicate neural tissues inside.

In contrast, the knee, elbow, and ankle are all examples of joints that allow for a range of movement. The knee is a hinge joint that enables bending and straightening of the leg, while the elbow allows for flexion and extension of the forearm. The ankle joint facilitates movement necessary for walking, running, and various other activities. Each of these joints plays a crucial role in the overall mobility of the body, highlighting the difference between movable and immovable joints.