What joint is commonly referred to as the "yes-no" joint?

The joint commonly referred to as the "yes-no" joint is the atlas-axis joint, also known as the atlantoaxial joint. This joint is located in the cervical spine and consists of the first cervical vertebra (the atlas) and the second cervical vertebra (the axis). The structure of this joint allows for a unique range of motion, facilitating both the nodding motion of the head which is associated with saying "yes" and the rotational movement of the head which allows for saying "no."

The atlas serves as a ring-like structure that supports the skull, and its articulation with the axis is key to this specific movement capability. As the atlas rotates around the odontoid process (or dens) of the axis, it gives the head the ability to pivot, enabling the "no" motion when turning from side to side.

In contrast, the other joints listed do not have this specific dual motion capability. For example, the scapulohumeral joint (shoulder) primarily allows for a wide range of arm movements but does not perform the yes-no motion. The femorotibial joint (knee) is predominantly involved in flexion and extension movements. The radioulnar joint primarily facilitates forearm rotation but