Which joint allows movement in one plane only?
- A. Elbow
- B. Shoulder
- C. Hip
- D. Wrist
Explanation
The elbow is a hinge joint, so it permits flexion and extension but no rotation, in the same way as the knee and the joints of the fingers. The shoulder and hip are ball and socket joints moving in every plane, and the wrist is a condyloid joint allowing movement in two planes. Restricting a joint to one plane is what makes it stable enough to bear load.