The arm muscles

Synonyms in the broadest sense

Arm muscles, arm muscle training, upper arm muscles


The arm muscles that are mostly on the upper arm, or Elbow joint muscles Acts on the function of the elbow joint. While three muscles are responsible for flexion, the triceps alone acts as a three-headed extensor of the upper arm. Since this muscle has three heads, it acts as a multi-jointed muscle and also causes adduction and retroversion in the shoulder joint.

Figure arm muscles

Figure right arm: A - muscles of the flexor side (palmar side) and B - muscles of the extensor side (dorsal side)

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

Upper arm muscles

The upper arm muscles are divided into two groups, the Flexors (Flexor) and the Extensors (Strecker). The flexors include the biceps brachii and brachialis muscles, and the extensors include the trizeps brachii (triceps) and anconeus muscles.

Of the Biceps brachii muscle has two parts. The caput longum (long "head") arises from a small protrusion (Supraglenoid tubercle) at the upper end of the humerus (Caput humeri). The caput breve (short "head") has its origin at the extension of the shoulder blade (Coracoid process). Both arms are placed on a small ledge (Radial tuberosity) on the spoke (forearm bone). The biceps tendon also pulls into the bicipital aponeurosis, part of the forearm fascia.

The biceps is for that diffraction (Flexion) and Outward rotation of the hand by turning the forearm (Supination) responsible. It also causes the arm to spread apart from the body (Abduction) and moving the arm forward (Anteversion). The biceps has a greater distance from the flexion / extension axis than the brachial muscle and therefore has a greater torque when flexing. With the elbow bent at right angles, the biceps is also the strongest supinator.

Of the Brachialis muscle lies under the biceps and is therefore closer to the flexion / extension axis than the biceps. Therefore, even small changes in length of the brachialis lead to large flexion movements in the elbow. So he is the one stronger flexors. In addition, a few fibers of the brachialis pull into the joint capsule of the elbow and tighten it, which is why it is also known as a capsule tensioner. The brachialis muscle has its origin in the anterior lower third of the humerus (Corpus humeri) and pulls to a rough muscle attachment point (Ulna tuberosity) at the top of the ulna.

Of the Triceps has three “heads”, the caput longum (long), lateral (to the side) and medial (towards the middle of the body). The caput longum begins at the outer edge of the shoulder blade (Infraglenoid tubercle). The lateral head has its origin on the lateral upper third of the humerus (proximal sulcus nervus radialis). The medial head arises from the lower third of the humerus (distal sulcus nervus radialis). All three parts pull towards the elbow. The triceps is for that Extension of the arm responsible and also causes the arm to be brought sideways to the body (Adduction).

Of the Anconeus muscle starts at the side elbow and moves to the upper, rear end of the ulna. It also causes a stretch and is at the same time like the M. brachialis Capsule tensioner.

Read more about the topic in the article: Upper arm muscles.

Forearm muscles

The Forearm muscles can also in Flexor, on the side of the palm of the forearm (palmar), and Extensor, on the side of the back of the hand of the forearm (dorsal) to be grouped. The flexors can also be divided into superficial and deep flexors.

The superficial ones include the pronator teres muscle, the palmaris longus, the flexor carpi radialis, the flexor carpi ulnaris and the flexor digitorum superficilis. All of them arise with at least a portion of the medial epicondyle (protruding bone at the lower end of the upper arm) and attach to the forearm or the hand bone and therefore cause the forearm to bend. All but the pronator teres pull up to the hand and therefore also cause a flexion there.

The pronator teres, the palmaris longus and the flexor carpi radialis muscles also cause the forearm to rotate inwards (Supination) due to its inclined course from the little finger side on the elbow to the thumb side on the forearm.
The flexor carpi radialis muscle also performs a radial abduction, which means that the hand is bent towards the spoke. The flexor carpi ulnaris muscle makes exactly the opposite movement, namely an ulnar abduction (to the ulnar). The flexor digitorum superficialis muscle also causes flexion in the metacarpophalangeal and median joints as it pulls to the middle bones of fingers 2-5 (all but the thumb). The palmaris longus muscle extends into the palmar fascia and tensions it.

The deep flexors include the flexor digitorum profundus, the flexor pollicis longus, and the pronator quadratus muscles. The flexor digitorum profundus muscle extends from the ulna to the phalanx of fingers 2-5 and thus flexes the wrist and the finger joints. The flexor pollicis longus muscle begins at the spoke and ends at the thumb distal phalanx. It leads to flexion of the thumb joints, opposition (touching the thumb and little finger) and radial abduction. The pronator quadratus muscle runs from the ulna to the radius and therefore causes the forearm to rotate inwards (pronation).

The Straightener of the forearm can be divided into 3 groups. The Radial group, the superficial extensor and the deep extensor. The radial group includes the brachioradialis, extensor carpi radialis longus and brevis muscles. All pull from the lateral epicondyle of the humerus (muscle attachment point near the elbow) along the radius to the hand. The brachioradialis muscle ends at the lower end of the radius and therefore only affects the forearm. Here it causes the forearm to bend and rotate in or out. Due to their attachment to metacarpal bones 2 and 3, the other two cause flexion in the elbow joint and extension of the hand as well as radial abduction (towards the spoke).

The superficial extensors include the extensor digitorum, the extensor digiti minimi, and the extensor carpi ulnaris. They all begin at the lateral epicondyle of the upper arm. The extensor digitorum and extensor digiti minimi (finger extensors) end in the dorsal aponeuroses of fingers 2-5 and 5, respectively. The extensor carpi ulnaris extends to the middle bone of the little finger. All of them cause the hand to stretch. The finger extensor also extends the finger joints 2-5 and the extensor carpi ulnaris also causes ulnar abduction.

The deep extensors are the supinator, the abductor pollicis longus, the Mm. extensor pollicis longus and brevis and the extensor indicis muscle. The supinator pulls from the lateral epicondyle to the radius and causes the arm to rotate outwards. The abductor pollicis longus and extensor pollicis brevis muscles begin on the back of the ulna, radius, and membrane between the two. The abductor pulls to the 1st metacarpal bone and makes a hand flexion, a radial abduction and an extension and an abduction (moving the thumb away from the palm). The extensor ends at the first thumb joint and causes radial abduction and extension of the thumb.

The extensor pollicis longus (thumb extensor) and the extensor indici (index finger extensor) have their origin on the back of the ulna and on the membrane. The thumb extensor pulls towards the thumb joint and ensures radial abduction (towards the spoke), wrist extension and extension and adduction of the thumb (pulling the thumb in). The index finger extensor ends in the dorsal aponeurosis of the index finger and extends the hand and index finger.

Hand muscles

The hand muscles can be divided into three groups.

The hand muscles can be divided into three groups, the thenar muscles (thumb muscles), the metacarpal muscles and the hypothenar muscles (muscles of the little finger).

The thenar muscles include the abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and adductor pollicis muscles. They all start on the palm of the hand and pull to varying degrees on the thumb. The abductor pulls towards the first phalanx of the thumb and causes an abduction (moving the thumb away from the hand) and an opposition (touching the thumb and little finger) as well as a flexion in the metatarsophalangeal joint in the saddle joint. The opponent ends at the first metacarpal bone and causes an opposition, flexion and adduction (leading to the hand). The flexor pulls towards the first phalanx of the thumb and causes flexion in the metacarpal and saddle joints and an opposition. The adductor also pulls on the first phalanx, causing adduction, opposition, and flexion in the metatarsophalangeal joint.

The metacarpal muscles consist of the Mm. lumbricales, Mm. interossei palmares and Mm. interossei dorsales. The Mm. Lumbricales arise from the tendons of the flexor digitorum profundus and extend radially to the dorsal aponeuroses of fingers 2-5 (spoke side). They cause the base joints to bend and the finger joints to stretch. The Mm. Interossei palmares extend from the metacarpal bones 2, 4 and 5 to the dorsal aponeuroses of the fingers 2, 4 and 5 and ensure flexion in the metatarsophalangeal joints, extension in the finger joints and adduction of the fingers to the middle finger. The Mm. Interossei dorsales begin at the metacarpal bones 1-5 and end at the dorsal aponeuroses 2-5. They lead to flexion in the metatarsophalangeal joints, extension in the finger joints, and abduction of fingers 2, 4 and 5 away from the middle finger.

The hypothenar muscles include the abductor digiti minimi, the flexor digiti minimi brevis, the opponens digiti minimi and the palmaris brevis muscles. They have their origin either in the palmar aponeurosis or in the carpal tunnel. The abductor ends on the first phalanx of the little finger and causes abduction and flexion in the metatarsophalangeal joint. The flexor also pulls towards the first phalanx, but only ensures flexion in the base joint. The opponent ends on the 5th metacarpal and leads to opposition and slight flexion of the 5th metacarpal. The palmaris muscle pulls towards the skin of the little finger and its task is to stretch the palmar aponeurosis.

Pain in the arm muscles

Muscle pain can have a variety of causes, including injuries, cramps, tension, muscle disorders, nerve disorders, and medication. Muscle injuries include sore muscles, bruises and strains, torn muscles or torn muscles.

Usually these arise Injuries while exercising. Strong, sudden muscle movements can lead to this, especially if the muscles have not been properly warmed up beforehand. Sports that often lead to such injuries are, for example, tennis, handball or weight training.

Other causes of muscle injuries can be kicks or blows, that is direct violence, be. At a Bruise or strain Movement and pressure pains are usually the result, in the event of a tear stabbing pain is predominant and a bruise can occur. Muscle spasms occur rarely in the arms, but can also occur and are usually caused by a magnesium deficiency and increased sweating. They come on very suddenly.

Pain in the arms could also be one Radiation of tension in the shoulders, neck or upper back be. These are caused by weak muscles, poor posture, a lot of sitting and lack of exercise.
Pain due to Muscle disorders can be caused by inflammation, for example. This can be caused by viruses (flu), bacteria (tetanus) or parasites, but also by autoimmune diseases such as Myasthenia gravis. Here the muscle can tire very quickly and no longer has full strength.

Non-inflammatory muscle diseases are also possible. This includes, for example Muscular dystrophy. Metabolic disorders such as an underactive thyroid are also conceivable. Furthermore can Nervous system disorders lead to muscle pain. These are for example Parkinson's, AS, multiple sclerosis or polio.

Some too Medication can trigger muscle pain, including Statins (especially during physical activity), penicillins (muscle weakness, cramps, pain) and alcohol (death of muscle cells).

Basically you can say that the pain is harmless if it only lasts for a short time and goes away on its own. If they last for several weeks, a doctor should be consulted.

Stretching the arm muscles

Below are various stretching exercises that you can do anywhere. The first four exercises are for the shoulder and arm muscles.

For the first exercise, stand (or sit) a little wider than hip-width. The left arm is stretched up and bent behind the head. Now grab your left wrist with your right hand behind your neck and pull it to the right until you pull it into your left shoulder and upper arm. Then repeat the whole thing for the right side.

For the next exercise, stand (or sit) in the same way as you did the previous one. The left arm is stretched up again and then bent back behind the head. Now pull your left elbow to the right with your right hand until it pulls back into your shoulder and upper arm. Now repeat again for the other side.

In the third exercise, the starting position is the same again. But now the left arm is stretched to the right in front of the body and the left hand is placed on the right shoulder. Now put your right hand around your left elbow and pull it to the right until it pulls into your left shoulder. Then repeat for the right side. In the fourth exercise, the legs are again in the same position, the left arm is again stretched upwards as at the beginning and is again bent behind the head. Now you take your left elbow with your right hand and I push it back and down until it pulls in the left upper arm. Then switch sides.

The last exercise involves stretching the forearm muscles. For this, the legs again a little more than hip width apart. Then stretch your left arm forward, palm down. Then stretch your hand up. Now pull your fingers gently towards your chest with your right hand and then repeat on the other side.


Training the upper arm muscles is particularly popular with male gym visitors. While the anterior (ventral) side of the musculature (Biceps, arm flexors, upper arm radial muscles) is specifically trained, the rear (dorsal) side develops during the Bench press and Neck press secondary with. Especially the Arm extensor (M.triceps brachii) of great importance in many sports movements.

Probably the best known arm muscle training is that Biceps workout. For example, you can stand up with your arms at your sides and a dumbbell in each hand. Now both arms are bent forward and up at the same time until it is no longer possible. This is then repeated as often as desired. This works the biceps. Alternatively, you can stand hip-width apart on a Thera-Band and hold the ends of the band in one hand and the other. The tape should be slightly taut with your arms stretched down to your sides. Now bend both arms again until it is no longer possible and slowly pull the tape upwards, then stretch your arm again and repeat.

For the Triceps For example, you can sit on a stool with your knees hip-width apart and your back straight. Then you take a dumbbell with both hands and hold it behind your head. The arms are bent at approximately a right angle and the upper arms are next to the ears. Now move the dumbbell slowly over your head, stretching your arms. Repeat this as often as you like.

Alternatively, you can use a Thera-Band again to help. Stand hip-width apart on the belt, your knees slightly bent. Take one end of the band with your hands and pull it back and up with both arms at the same time. The arms are first held to the side of the body, then bent to the side. Now the elbows are pulled up behind both ears and then the arms are stretched up behind the head. The tape is always pulled upwards. This can be repeated as often as you like.

For the Forearm muscle training you can sit down with your knees hip-width apart. Now you take a barbell or two dumbbells in your hands. The upper body is bent slightly forward, the back remains straight. The forearms are placed on the knees with the palms facing up. Now stretch your hands over with the dumbbells and then slowly bend them towards your body. Perform this exercise slowly and repeat as often as you like.

Exercises for each muscle group

Three-headed arm extensor

(M.. triceps brachii)

  • Triceps extension
  • Bench press
  • Neck press
  • Nosebreaker

Two-headed arm muscle
(M. biceps brachii )

  • Biceps curl
  • Lat pull (tight)
  • rowing

Arm flexors
(M.. brachialis)

  • Biceps curl

Upper arm radial muscle
(M.. brachioradialis)

  • Biceps curl