Question

What elbow and forearm motions occur to bring the palmar surface of the hand to the mouth?

A. Elbow extension with the forearm in either pronation or supination
B. Elbow flexion and forearm pronation
C. Elbow extension with the forearm in a neutral position of rotation
D. Elbow flexion and forearm supination

Answer 1

To bring the palmar surface of the hand to the mouth, elbow flexion and forearm supination take place. Elbow flexion is aided by muscles such as the biceps brachii, while supination is facilitated by the supinator muscle.

Step-by-step explanation:

To bring the palmar surface of the hand to the mouth, the actions that occur are elbow flexion and forearm supination. When we bring our hand towards our mouth, like when eating, we need to bend the elbow to decrease the angle between the upper arm and the forearm. This is known as elbow flexion. The muscles that aid in this movement include the biceps brachii, brachialis, and brachioradialis.

Concurrently, the forearm must rotate to a position that places the palm facing upward or forward, which is the action of supination. This movement involves the supinator muscle and is the opposite of pronation, where the palm would face downward or backward. Supination allows us to scoop up and grasp items, hence viewing it as the movement used to "scoop up soup" with a spoon.

Therefore, the correct answer is D. Elbow flexion and forearm supination.

Answer 2

To bring the palmar surface of the hand to the mouth, the motions involved are elbow flexion to bring the hand closer to the head, and forearm supination, which aligns the palm facing the mouth. The correct option, therefore, is elbow flexion and forearm supination. Therefore, the correct option is D. Elbow flexion and forearm supination.

Step-by-step explanation:

To understand what elbow and forearm motions occur to bring the palmar surface of the hand to the mouth, we must consider the actions of the muscles involved and the resulting movements of the bones of the forearm. The forearm consists of two bones, the radius, and the ulna. These bones work together to perform various movements, including supination and pronation.

The action of elbow flexion is predominantly carried out by muscles including the biceps brachii, brachialis, and brachioradialis. Flexion of the elbow brings the hand closer to the head, while supination, which is carried out by the supinator muscle and assisted by the biceps brachii, turns the radius and ulna so that they lie parallel and the palm faces forward.

When bringing the hand to the mouth, the forearm should be in the supinated position to align the palm facing the mouth, which is part of a common daily activity such as eating with a spoon. Therefore, the combination of motions that would occur to bring the palmar surface of the hand to the mouth is elbow flexion coupled with forearm supination. Hence, the correct option is D. Elbow flexion and forearm supination.