Which joint type allows for flexion and extension in a single plane?

Which joint type allows for flexion and extension in a single plane?

• A. Hinge
• B. Plane
• C. Saddle
• D. Condyloid

Answer: (A)

The hinge joint is specifically designed to allow movement predominantly in one direction, enabling flexion and extension. This joint type resembles a door hinge, functioning similarly by allowing a wide range of motion around a single axis. An excellent example of a hinge joint is the elbow, which facilitates the bending and straightening of the arm.

In contrast, the other joint types mentioned have different movement capabilities. The plane joint allows for gliding movements between bones but does not primarily facilitate flexion and extension. The saddle joint permits movement back and forth and side to side, providing more complex motions than just flexion and extension. Lastly, the condyloid joint allows for movement in two planes (including flexion/extension and abduction/adduction), which is more versatile than just the single-plane movement characteristic of hinge joints. Hence, the hinge joint is the appropriate choice for movement restricted to flexion and extension in one plane.