Final answer:
The basic motions of pushing and pulling of the upper extremity are flexion and extension. Flexion involves bending the joint, while extension straightens it. Also, pronation and supination allow for the rotational movement of the forearm.
Step-by-step explanation:
The basic motions of pushing and pulling of the upper extremity are described as flexion and extension. In the limbs, flexion is a movement that decreases the angle between the bones at a joint, essentially bending the joint. Conversely, extension increases the angle between the bones, straightening the joint. For example, bringing the forearm up towards the shoulder is flexion, while straightening the arm downwards is extension. These movements are carried out by muscles such as the biceps brachii, brachialis, and brachioradialis for flexion, and various triceps muscles for extension.
Movements such as pronation and supination are also essential for upper limb function. Supination of the forearm turns the hand so the palm faces forward with the radius and ulna bones parallel, while pronation turns it so the palm faces backward, causing the bones to cross in an X-shape. These actions allow the hand to rotate and are necessary for many daily tasks.