What type of joint is capable of movement in every plane?

• A. Ball and Socket
• B. Hinge
• C. Pivot
• D. Saddle

Answer: (A)

Ball-and-socket joints allow movement in every plane because the rounded head of one bone fits into a cup-shaped socket on the other, creating a looser, multiaxial connection. This setup lets the limb move forward and backward, side to side, and rotate, enabling flexion, extension, abduction, adduction, rotation, and circumduction. The shoulder and hip are classic examples, giving the most freedom of movement in the body.

In contrast, hinge joints move mainly in one plane (flexion and extension), like an elbow or knee. Pivot joints allow rotation around a single axis, as with the proximal radioulnar joint. Saddle joints permit movement in two planes but not full rotational movement, as seen in the thumb’s carpometacarpal joint. So, for movement in every plane, the ball-and-socket joint is the right type.