The upper arm

General

The upper arm consists of a humerus bone (Humerus) and several joint connections to both the shoulder (shoulder joint) and the bones of the forearm (elbow joint).
In addition, the upper arm has numerous

• Muscles,
• annoy
• Vessels

The upper arm bone (humerus)

The humerus is a long tubular bone that is divided into different parts. The main part of the humerus forms the corpus humeri. On this is the humerus head (Caput humeri), which carries the articular surface to the shoulder joint (Humeral condyle).

Towards the middle (medial) and side (lateral) there are two epicondyles (bony protrusions) that serve as attachment points for various muscles of the shoulder joint. The neck of the upper arm is connected to this humeral head (Collum anatomicum of the humerus). The joint capsule of the shoulder joint is anchored to this.

If you look at the humerus from the front, you will find two other bones. That is on the side

• Tuberculum majus, from which the continuing crista tuberculis majoris emerges. That is towards the middle
• Tuberculum minus, with the continuing Christa tuberculis minoris. These points serve as attachment points for various muscles.

A groove, the sulcus intertubercularis, runs between these bony protrusions. The tendon of the long biceps head runs in this. On the lateral part of the bone shaft there is a roughened surface, the so-called deltoid tuberosity. This serves as the starting point for the deltoid muscle.

The entire shaft of the humerus is divided into two surfaces,

• the anteromedial and
• the anterolateral facies.

Both bone edges continue towards the forearm as bone edges and then merge into the medial and lateral epicondyle.

On the back of the humerus there is a groove for the radial nerve (Radial sulcus), this winds around the humerus. At the connection between the humerus and forearm bones, the humerus forms a bony roll, the trochlea humeri with the coronoid fossa. Medial to this is a channel for the ulnar nerve.

In addition, the humeral capitulum is formed, which contains a radial fossa for the radial nerve. On the posterior surface of this transition is the olecranon fossa, which contains the olecranon of the forearm.

What is the humerus head?

The humeral head, also humeral head (lat. Caput humeri) is the end of the humerus near the body. This end of the bone is spherical and lies in the shoulder socket. Thus, the humerus head and the shoulder socket form the shoulder joint, a ball joint. The humerus head is larger than the gel socket, which means that the joint has three degrees of freedom and is therefore very mobile. This mobility is increased because the joint socket is very flat. The surface of the humeral head consists of a solid and thick layer of cartilage. This form of cartilage is also called hyaline cartilage and is firmly attached to the bone tissue. This smooth surface is important for frictionless movement in the joint and serves to absorb shock. The head of the humerus is clearly separated from the rest of the humerus, the corpus humeri, and merges into the so-called colum, neck. This transition point is particularly at risk for broken bones.

Figure humerus

Humerus

1. Humerus head -
   Caput humeri
2. Big hump -
   Greater tuberosity
3. Small hump -
   Lesser tuberosity
4. Anatomical neck -
   Collum anatomicum
5. Surgical Neck -
   Collum chirurgicum
6. Upper arm shaft -
   Corpus humeri
7. Inner femoral knot -
   Medial epicondyle
8. Outer femoral knot -
   Lateral epicondyle
9. Upper arm head -
   Capitulum humeri
10. Upper arm roll -
    Trochlea humeri
11. Elbow pit -
    Olecranon fossa

You can find an overview of all Dr-Gumpert images at: medical illustrations

Upper arm muscles

On the upper arm, the muscles become one

• rear extension group (Extensors, lying dorsally)
• forward flexor group (Flexors, lying ventrally)

Both groups are supported by the upper arm fascia (Faszia brachii) and are separated from one another by the middle and lateral intermuscular septum.

Flexor muscles:
The flexors of the upper arm are

• the biceps brachii muscle
• the brachialis muscle
• the coracobrachialis muscle

All flexors are innervated by the musculocutaneous nerve.

The biceps brachii muscle consists of two large muscle heads and therefore has two different origins.

• The long head (long part) arises from the supraglenoid tuberosity of the shoulder blade (Scapula),
• the caput breve (short part) of the coracoid process of the scapula.

In the course of the process, the two muscle heads unite and jointly attach to the radial tuberosity of the humerus. The biceps brachii muscle is a two-jointed muscle and therefore has many functions. The tendon of the caput longum runs over the head of the humerus and through the shoulder joint capsule. He also crosses the elbow joint space.
In the shoulder joint it leads to

• Internal rotation
• Anteversion (stretching the arm forward)
• long part of the muscle used for adduction
• short part for abduction in the shoulder joint

However, the main function of the muscle is to move in the elbow joint. Here the muscle causes the forearm to flex and rotate. This enables the palm of the hand to move upwards.

The brachialis muscle arises on the front of the humerus and attaches to the elbow joint capsule. As a result, he bends the forearm, regardless of the hand position. Compared to the aforementioned biceps brachii muscle, it is the significantly stronger flexor and is therefore particularly important when lifting heavy loads.

The coracobrachialis muscle arises from a protruding bone on the shoulder blade (Coracoid process) and starts on the middle surface of the humerus. Its main task is to

• Internal rotation
• Adduction (approaching the body)
• Anteversion (stretching forward) of the upper arm in the shoulder joint

Extensor muscles:
The extensors of the upper arm lie on the back surface of the same. This includes the

• Triceps brachii muscle
• Anconeus muscle.

The triceps brachii muscle has three muscle heads, which originate in different places.

• The long part (Caput longum) has its origin in the infraglenoid tubercle of the shoulder.
• The lateral part (Caput laterale) arises on the lateral and posterior surface of the humerus.
• The middle head of the muscle (Caput mediale) arises on the middle and rear surfaces.

All three parts put together on the olecranon of the ell (Ulna) on. Some bursa are often stored here as plain bearings. The main function of this muscle is to stretch the elbow joint. The very small anconeus muscle arises from the lateral epicondyle of the upper arm and also attaches to the olecranon. Like the triceps brachii muscle, it serves to stretch the elbow joint. Both muscles are innervated by the radial nerve.

Arm muscles

1. Two-headed upper arm muscle
   (Biceps) short head -
   M. biceps brachii, caput breve
2. Two-headed upper arm muscle
   (Biceps) long head -
   M. biceps brachii, caput longum
3. Upper arm muscle (arm flexor) -
   Brachialis muscle
4. Three-headed upper arm muscle
   (Triceps) side head -
   M. triceps brachii, caput laterale
5. Three-headed upper arm muscle
   (Triceps) long head -
   M. triceps brachii, Caput longum
6. Three-headed upper arm muscle
   (Triceps) inner head -
   Triceps brachii muscle,
   Caput mediale
7. Knobby Muscle - Muscle anconeus
8. Elbow - Olecranon
9. Upper arm spoke muscle -
   Brachioradialis muscle
10. Long spoke-side hand straightener -
    Muscle extensor carpi radialis longus
11. Spoke-sided hand flexor -
    Muscle flexor carpi radialis
12. Superficial finger flexor -
    Muscle flexor digitorum superficialis
13. Long palm tendon tensioner -
    Palmaris longus muscle
14. Extensor tendon strap -
    Retinaculum musculorum extensorum
15. Short spoke-side hand straightener -
    Muscle extensor carpi radialis brevis
16. Elbow-sided hand flexor -
    Muscle flexor carpi ulnaris
17. Finger extensor -
    Muscle extensor digitorum
18. Trapezius -
    Trapezius muscle
19. Deltoid -
    Deltoid muscle
20. Pectoralis major -
    Pectoralis major muscle

You can find an overview of all Dr-Gumpert images at: medical illustrations

Joints of the upper arm

The upper arm is about that

• Shoulder joint with the shoulder and over that
• Elbow joint connected to the forearm.

The shoulder joint is a ball joint that allows three different directions of movement:

• Spreading (Abduction)
• Bring up (Adduction)
• Demonstration (Anteversion) or the diffraction (Felxion)
• Return (Retro version), or the stretching (Extension)
• Rotation inwards and outwards (Internal rotation, External rotation)

The articular surfaces of the shoulder joint are derived from the head of the humerus (Caput humeri) and the articular surfaces of the shoulder blade (Glenoid scapular cavitas) and enables the greatest mobility of all joints in the human body.

They are in the elbow joint

• distant (distal) End of the humerus, as well as the
• body-hugging (proximal) Ends of cubit (Ulna) and spoke (radius) in an articulated connection.

The three compartments each form a joint. As a result, the elbow joint consists of three different joints.

• The humerus stands with the ulna ( Articulatio humeroulnaris) and with the spoke (Articulatio humeroradialis) in an articulated connection.
• In addition, there is another joint between the two (proximal) Ends of ulna and radius (Articulatio radioulnaris proximalis).

Through these different joints a flexion (Flexion) and elongation (Extension) as well as the rotation of the forearm or the palm upwards (Supination) and down (Pronation) possible.

Vascular supply

Arteries

The arm artery (Brachial artery) is the extension of the axillary artery (Arteria axillary) and runs along the arm to the middle of the biceps tendon, which is why your pulse can easily be felt with your arm flexed.
There are three main main branches that branch off the arm artery in its course:

• The deep arm artery (Deep brachial artery) branches off and runs to the elbow joint, which supplies it with its terminal branches.
• The superior lateral ulnar artery (Arteria collateralis ulnaris superior) branches off late and then takes its course on the back (extensor side) of the upper arm.
• The lower lateral ulnar artery (Inferior ulnar sollateral artery) branches off even later and runs in the direction of the ulna.

There are also numerous smaller arteries and arterioles that supply the entire upper arm and its muscles with oxygen and nutrient-rich blood.

Veins

As in the entire body, there are two types of veins in the upper limb.

• The deep veins are usually named like the arteries and run with them.
• The superficial veins are usually accompanied by lymphatic vessels and are partly recognizable from the outside.

They are connected to the deep veins via vein bridges. There are two main trunks of superficial veins on the arm.

• The basilica vein runs relatively centrally on the upper arm and penetrates about halfway down into one of the large veins (Brachial vein) to flow.
• The cephalic vein runs laterally on the upper arm and penetrates deeply at the level of the collarbone. There it opens into the large subclavian vein that runs along the collarbone.

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On the upper arm, some nerves run from the arm nerve plexus (Plexus brachialis).

The musculocutaneous nerve arises from the lateral part of the plexus and supplies the motor with it

• Coracobrachialis muscle
• Biceps brachii muscle
• Brachialis muscle

In addition, sensitive branches branch off, which innervate the forearm.

The radial nerve runs together with the brachial artery and loops around the humerus. It innervates the motor

• Triceps muscle and pulls to the crook of the elbow.

There it splits into different branches and then innervates parts of the forearm.

The median nerve arises from the lateral part of the plexus and branches into one

• side and one
• middle proportion.

It runs in the sulcus bicipitalis medialis to the elbow and from there extends between the muscles of the forearm to the wrist.

The ulnar nerve originates from the middle branch of the plexus and runs relatively straight on the elbow side of the arm. However, it changes in between and runs with it

• times on the stretch side and
• times on the flexor side of the arm.

Around the middle of the upper arm, the nerve penetrates the muscles and thus reaches the back. There the ulnar nerve runs in a canal, which makes it particularly easy to irritate the elbow (Funny bones). As it progresses, it steps back on the flexor side and then innervates numerous muscles of the forearm.

The sensitive supply area of ​​the upper arm is difficult to divide. A distinction is made between four areas which are supplied by different nerves.

• The middle area on the inside of the upper arm is supplied by the medial cutaneous nerve (from the middle part of the plexus).
• The lateral area is innervated close to the body by the nervus cutaneus brachii laterlis superior (from the nervus axillaryis),
• the part distant from the body through the nervus cutaneus brachii lateralis inferior (from the nervus radialis).
• The posterior area is very small and is supplied by the posterior brachial cutaneous nerve, which also comes from the radial nerve.

Diseases of the upper arm

Upper arm fracture

A broken bone in the upper arm is also called a humeral fracture, whereby the humer (upper arm bone) has broken or broken through. It is a fairly common break that usually happens after a fall on the shoulder or arm or as a result of external violence in an accident, for example. Often the humerus breaks below the end at the shoulder, as it is particularly narrow there and so breaks more easily. However, there is also an increased risk of breakage with certain diseases. These include tumor diseases or osteoporosis. Due to osteoporosis, women in old age suffer from a fracture of the upper arm significantly more often than men, as the risk of osteoporosis is significantly lower for them. When the arm is broken, pain in the upper arm spreads, it can swell, and it may be deformed. The bruise that forms on the arm is usually noticeable. Moving the arm is then often painful and can also make noises. An open fracture can be easily recognized from the outside and should be presented to a doctor immediately. In order to be able to make his diagnosis, the doctor will ask exactly how the accident happened, examine the affected arm and examine it physically. The broken arm will be x-rayed and possibly a computed tomography will be done as imaging support. The x-rays are used to decide whether the arm needs conservative treatment or surgery. Non-surgical therapy is often used for crossbreaks, in which the bone is straightened if necessary and then immobilized so that it can grow back together on its own. For this, either a bandage, a splint or a cast is put on for several weeks. If the bone has broken into several fragments that have shifted, the arm is surgically straightened.

Read more about this at: Upper arm fracture- you need to know that

Pain in the upper arm

The base of the upper arm is formed by the upper arm bone, also called the humerus, which is connected to the trunk by the shoulder joint and to the forearm by the elbow joint. Many muscles, nerves, tendons, fasciae and vessels surround the humerus and can thus be the cause of pain. Often painful injuries arise from outside, from an accident or a fall. This includes bruises, bruises or breaks.

However, it is also possible to overstrain it through intense exercise, so that the muscles have been overused and are painful. In the most harmless case, this is just a sore muscles, which disappears on its own after the arm is protected. However, if the muscle pain results from long-term incorrect strain, the muscles on the upper arm can harden and become tense. The resulting increased muscle tension presses on the surrounding tissue and causes pain. The pain in the upper arm can be very different, it can be drawn, stabbing, throbbing at certain points or spread over a large area. If nerves are to blame for the pain, a sensory disorder is usually an accompanying symptom. This can show up as tingling or numbness in the arm. In such a case it is possible that a nerve is pinched. Another possible cause of upper arm pain can be a heart attack, i.e. an organ. However, other symptoms usually occur, such as heart pain, tightness in the chest, etc.

also read: Pain in the upper arm- what do I have?

Pulled upper arm

A muscle strain on the upper arm is caused by a sudden, unnatural stretching of a muscle. Such uncoordinated movement often happens during exercise. The muscle fibers are not damaged, they harden because they contract like a spasm. As a result of this contraction, structures in the muscle that cannot stretch well are protected from injury. Correspondingly, cramp-like pain develops, which gradually increase and harden the muscle. If this occurs during exercise, you should immediately take a break and take it easy on your arm, cool it and put your arm up, as less blood flows into it and thus counteracts the pain. After resting for about one to two weeks, the strain will usually heal again.

Inform yourself: Muscle strain

Enchondroma on the upper arm

An enchondroma is almost always located on the humerus head in the shoulder area. It is a benign cartilage tumor, the exact cause of which is unknown. Scientists suggest that a hereditary component could play a role. Since an enchondroma can grow in childhood but hardly causes symptoms, it is usually discovered as an incidental finding in adulthood. They can be seen on x-rays or magnetic resonance imaging images that were taken because of other ailments. After the diagnosis, the enchondromas on the upper arm are usually treated because they can become malignant. During an operation, the enchondroma is removed and the space created is filled with a bone filling material (bone graft).

Read more about this: Enchondromas

Muscle twitching in the upper arm

Muscle twitching can occur in very different muscle groups in the body, but they are particularly common in the extremities, including the upper arm. These are involuntary, i.e. not deliberately controllable, suddenly occurring contractions of the upper arm muscles. The strength and duration of the twitches can be very variable. It is possible that these are twitches that are barely visible to the eye, but it is also possible that the twitches are so severe that the whole arm moves. Nerve cells transmit the impulses for contraction to the muscle, which is why a disease of the nervous system must sometimes be considered as a trigger. Furthermore, deficiency symptoms, medication or circulatory disorders are also possible causes.

Upper arm bandage

Bandages on the upper arm are particularly common in connection with the elbow, as joints suffer particularly from a lot of sporting activities and computer work. In addition to overloading, incorrect loads can also lead to problems. This can cause inflammation and injuries. A typical clinical picture is tennis elbow, in which the tendon tissue is diseased. To heal such injuries, a bandage is placed around the upper arm and elbow. However, there are also injuries to the shoulder area that lead the doctor to recommend that you wear a bandage. The bandage takes on a joint-relieving, protective and supporting function. The bandage is relatively tight and yet adapts comfortably to the movements of the body. The upper arm bandage is not only used during the healing process, but also to prevent possible injuries caused by overuse, especially in sports.

Arm lift

With an upper arm lift, tissue is removed from the underside of the upper arm, which is particularly visible when the arm is raised. In the vernacular it is also spoken of waving arms. These can arise from slack connective tissue or occur after severe weight loss. The surgical upper arm lift removes the hanging tissue and the upper arm gains shape. This operation is an aesthetic plastic surgical procedure that has no relevance for body health. Before the procedure, the surgeon marks the inside of the upper arm and the armpit where the incisions are to be made. The operation is now performed under either general or local anesthesia. Often a simple skin removal is performed, leaving scarcely visible scars. In this case, the cosmetic scars are located on the inner area of ​​the upper arm, the aim is to produce scars that are as inconspicuous as possible. It is also possible that in addition to a skin removal, excess fat is also removed. There is also the option of tightening the upper arm just by removing fat. During the operation, a drain is placed through which wound water can drain away. The operation usually only takes one to two hours, after which the patient remains briefly in the clinic for observation, but can go home very quickly, only with a bandage around the upper arms.

More about this at: Arm lift

How can you lose weight on the upper arm?

In order to get slim and beautiful upper arms, many people want to lose weight on the upper arm. However, it is hardly possible to specifically lose weight on only one part of the body, since the loss of fat cannot be precisely controlled, just as little as the accumulation of fat. Accordingly, in addition to targeted upper arm training, overall body fat must be reduced. What can be achieved through healthy and low-calorie food. Instead, you should eat particularly rich in protein and fiber, as this depletes your fat reserves. Sports should be played on the side. So that the arm circumference is reduced, i.e. mainly fat is broken down and not many muscles are built up on the arm, it is advisable to carry out a sports program that includes the whole body. However, there are also exercises that specifically train the upper arm and thus promote muscle building there and define the arm more. These exercises include anyone who works the triceps. It is particularly important to pay attention to the regularity of the execution of the exercises, as successes can only be achieved after a while.

For more information, read our article:
So you can lose weight on the upper arm!

Summary

Of the upper arm is an important part of our body because it is im Shoulder joint can perform numerous movements and for the movements and all functions of the Forearm and with it the hand necessary is.

In addition, the upper arm has numerous strong muscles, especially the

• biceps and
• Tricepswhich are visible from the outside in well-trained athletes.

They are essential for all holding and strength exercises of the arm.

The Vessels are very numerous and the inflow to Arterial network of the arm is so large that the arm artery can easily be tied off as soon as the deep arm artery is branched off.

The annoy all come from the Nerve plexus of the arm (Brachial plexus) and innervate the muscles and skin of the upper arm in various ways.