If you lay your forearm along a table, you can rotate it so that your hand changes from a palm-down to a palm-up position. This is possible because your radius and ulna join at a
A) ball-and-socket joint.
B) hinge joint.
C) pivot joint.
D) ligament.

Question

Quizplus · Accepted Answer

The rotation of the forearm is made possible because of the pivot joint formed by the radius and ulna bones. A pivot joint allows rotational movement in a single plane, and this type of joint allows the radius bone to rotate around the ulna bone, resulting in the change of the hand's position from palm-down to palm-up. A ball-and-socket joint allows movement in all directions, while a hinge joint allows movement in only one direction. A ligament is a band of connective tissue that connects bones to other bones. None of these options explain the specific type of joint that allows for forearm rotation.

If You Lay Your Forearm Along a Table, You Can