Muscles of the upper arm

The upper arm mainly does holding work and therefore requires large, strong muscles. These include the biceps muscle and the brachial muscle. The biceps muscle, also called biceps, is a two-headed muscle that originates in the shoulder area and from here is attached to the ulna under the elbow joint.

The biceps impresses some athletes as a strongly developed upper arm muscle. In the elbow joint, it ensures that the elbow is flexed when we are tensed, and also that we can turn the palm of our hand inwards when the elbow is bent (supination). In addition, the biceps ensures that we can extend the upper arm away from the body when the shoulder joint is tensed and also rotate the shoulder inwards when the elbow is bent.

The musculus brachialis is somewhat hidden underneath the biceps and is therefore only visible from the outside in well-trained athletes. It extends from the humerus to the radius. If the muscle is tensed, this results in flexion in the elbow joint.

On the back of the upper arm there are also upper arm muscles. It is a 3-headed muscle, the muscle triceps brachii or short the triceps. This pulls in the area of the shoulder and the back upper arm to the elbow (olecranon), which is also known as the funny bone. When the triceps is tensed, the elbow joint is stretched. So if a patient does dumbbell training, he first trains the biceps and the brachii muscle when he pulls the dumbbells up and flexes the elbow joint, then he trains the triceps when he lets the dumbbells go down slowly and stretches the elbow joint straight again.

Muscles of the forearm

In contrast to the upper arm muscles, the forearm muscles are not holding muscles, but rather support the hand in executing even small and very delicate movements. Therefore, there are an enormous number of forearm muscles compared to the upper arm muscles. A total of five superficial and three deep flexor muscles (flexors) can be distinguished.To the five superficial flexors belong: All five muscles originate on the inner (medial) side of the elbow joint and extend from here to the hand and sometimes to the fingers.

When these muscles are tensed, there is a slight flexion in the elbow joint and a flexion in the wrist and fingers. The three deep flexors include: The first two muscles originate from the inner surface of the forearm bones and extend from there to the fingers. When these muscles are tensed, there is a slight flexion in the elbow joint and a flexion in the wrist and fingers.

The Musculus pronator quadratus, on the other hand, pulls in the lower part of the forearm from ulna to radius, thus ensuring a certain security in the wrist on the one hand and a turning movement of the hand on the other hand, as if one wanted to cut a loaf of bread and had to turn the hand so that the back of the hand points upwards. This movement is called pronation in medicine, hence the name of the muscle. The next group of forearm muscles is the so-called radialis group.

The radius is a bone of the forearm and is called a radius in normal usage. The radialis muscles all originate in the area of the elbow joint and from there they move along the radius to the wrist. When this muscle group is tensed, there is on the one hand a weak flexion in the area of the elbow joint and on the other hand muscles help to make a complete fist closure.

In addition, tensing of this muscle group causes the wrist to bend to the side of the spoke. This includes: The last group of forearm muscles are the extensor muscles. Here again, a distinction is made between superficial extensor muscles and deep extensor muscles.

The superficial extensors include All three originate in the area of the elbow joint and draw from here to the fingers. If there is tension in the corresponding muscles, we stretch the wrist as well as the finger joints, we can then spread the fingers. The deep extensors also serve to move the hand.

The deep extensors include: The first of these muscles allows us to turn the arm (supination) and therefore stretches from the ulna to the radius. The next three muscles originate in the area of the forearm and extend from there to the thumb. When the muscles contract, they are mainly used for the mobility of the thumb and ensure that we can stretch the thumb away from the hand and also pull it back to the hand (abduction and adduction).

In addition, they help to pull the wrist to the side of the radius. The last muscle, the Musculus extensor indicis, also originates in the area of the forearm and draws from here to the second finger. When tensed, it stretches the wrist and the second finger.

The Musculus pronator teres
The flexor digitorum superfiscialis muscle
The flexor carpi radialis muscle
The Musculus flexor ulnaris
And the musculus palmaris longus.
The Musculus flexor digitorum profundus
The flexor pollicis longus muscle
And the musculus pronator quadratus.
The brachioradialis muscle
The Musculus extensor carpi radialis longus
And the musculus extensor carpi radialis brevis.
The Musculus extensor digitorum
The Musculus extensor digiti minimi
And the musculus extensor carpi ulnaris.
The Musculus supinator
The abductor pollicis longus
The Musculus extensor pollicis longus et brevis
And the musculus extensor indicis.