Which of the following is NOT included in the upper extremities?

The leg is not included in the upper extremities because it is part of the lower extremities. Upper extremities refer specifically to the parts of the body that are attached to the shoulder and include the shoulder itself, the upper arm, elbow, forearm, wrist, and hand. The shoulder connects the arm to the torso, while the elbow allows for the bending and straightening motion of the arm, and the forearm connects the elbow to the wrist. Each of these components plays a significant role in the mobility and function of the arm. Therefore, since the leg is associated with the lower extremities—consisting of the thigh, knee, lower leg, and foot—it does not belong in the category of upper extremities.