Question

Is a ball and socket joint a uniaxial joint because motion is limited to rotation in a single plane?

Answer 1

Uniaxial or uniplanar joints (also called hinge joints) rotate in one axis, allowing movement in one plane. The elbow joint is a hinge joint because it only allows movement forward and backward (flexion and extension) in the sagittal plane. Biaxial or biplanar joints rotate in two axes, allowing movement in two planes.