Which of the following type of joint is proximal radioulnar joint?
**Core Concept**
The proximal radioulnar joint is a type of synovial joint that connects the radius and ulna bones in the forearm, allowing for rotational movement. This joint is essential for forearm pronation and supination, enabling the hand to perform various functions.
**Why the Correct Answer is Right**
The proximal radioulnar joint is a pivot joint, which is a type of synovial joint that allows for rotational movement around a single axis. In this joint, the radius bone rotates around the ulna bone, enabling the hand to pronate (rotate downward) and supinate (rotate upward). The joint is stabilized by the annular ligament, which encircles the head of the radius and provides additional support.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the distal radioulnar joint is located at the opposite end of the forearm, near the wrist, and does not allow for the same type of rotational movement as the proximal radioulnar joint.
**Option B:** This option is incorrect because the elbow joint, also known as the humeroulnar joint, is a hinge joint that allows for flexion and extension of the forearm, but not rotational movement.
**Option C:** This option is incorrect because the wrist joint, also known as the radiocarpal joint, is a complex joint that allows for flexion, extension, abduction, and adduction of the wrist, but not rotational movement of the forearm.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the proximal radioulnar joint is responsible for forearm rotation, which is critical for various hand functions, including grasping and manipulating objects. Injury to this joint can lead to limited range of motion and weakness in the forearm.
**Correct Answer:** C. Pivot joint.