Forearm Musculature | Forearm

Forearm Musculature

The musculature of the forearm consists of numerous, also smaller muscles. In order to keep the overview, the muscles are divided into a This is still in a These are still in a This is still the muscles of the spoke. All these muscles are innervated by the median nerve and originate mainly from the medial epicondylus of the upper arm.

The pronator teres muscle consists of two muscle heads and thus also originates from the coronoid process of the ulna. It starts at the middle third of the radius and is primarily responsible for the downward rotation of the palm of the hand in the elbow joint (pronation).

  • Front (ventral) and one on the
  • Back surface (dorsal) lying muscle group.
  • Superficial and a
  • Deep layer structured.
  • Musculus pronator teres,
  • Musculus flexor carpi radialis,
  • Musculus palmaris longus,
  • Musculus flexor digitorum superficialis and the
  • Musculus flexor carpi ulnaris together.

The flexor carpi radialis muscle extends from the epicondylus medialis over the carpal bones and is attached to the second metacarpal bone.

In the elbow joint, it thus leads to the The musculus palmaris longus radiates into the muscular aponeurosis of the palm and flexes the forearm in the elbow joint, as well as the wrist. The muscle flexor digitorum superficialis has two muscle heads. One originates from the epicondylus medialis, the other from the radial head.

It starts with four tendons at the metacarpal bones of the 2nd to 5th finger. In the elbow joint and wrist, the muscle leads to flexion, and in the wrist to movement of the hand towards the little finger (abduction after ulnar). In the metacarpophalangeal joints and some small joints between the fingers, the muscle also leads to flexion.

The last muscle in this group is the flexor carpi ulnar muscle. This muscle also consists of two heads, one of which originates from the epicondylus medialis of the upper arm, the other from the olecranon of the ulna. It is the longest muscle and moves to various carpal bones.

The main function of the muscle is to bend the hand in the wrist. Unlike all other muscles in this group, the flexor carpi ulnar muscle is innervated by the ulnar nerve. The deep layer of this anterior muscle group consists of the The pronator quadratus muscle originates at the distal end of the ulna on the inside of the hand and moves to the distal end of the radius, also on the inside of the hand.

Thus, this muscle lies almost squarely on the front of the forearm and causes the palm of the hand to rotate downwards (pronation). It is supplied from a branch of the median nerve. The muscle flexor digitorum profundus originates from the front surface at about half of the ulna and is located at the finger joints of the second to fifth finger.

It thus bends the fingers and the wrist. The innervation is performed by the median and ulnar nerves. The muscle flexor pollicis longus originates at the radius and then runs to the base joint of the thumb.

It thus performs its function as a flexor of the thumb. This muscle is also responsible for the opposition movement of the thumb, i.e. the movement of the thumb towards the palm. It is also supplied by the median nerve.

The superficial layer of the forearm muscles located on the back is innervated by a branch of the radial nerve. It consists of the All these muscles originate at the lateral epicondylus of the upper arm.

  • Diffraction and
  • Pronation, at the wrist it bends the hand and is
  • Abduction, i.e. the movement towards the thumb is responsible.
  • Musculus pronator quadratus, the
  • Musculus flexor digitorum profundus and the
  • Musculus flexor pollicis longus.
  • Musculus extensor digitorum,
  • Musculus extensor digiti minimi and the
  • Musculus extensor carpi ulnaris.

The Musculus extensor digitorum branches out in its course and attaches to the finger joints of the 2nd to 5th finger and the wrist.

This makes it the strongest flexor of the wrist and finger joints. The Musculus extensor digiti minimi starts at the little (5th) finger and stretches it. The muscle may also be absent, although this does not restrict its function, since the extensor digitorum muscle then takes over the stretching function.

The extensor carpi ulnaris muscle starts at the base of the 5th metacarpal and serves as a capsule amplifier. It is also responsible for lateral wrist movement (ulnar abduction). The deep layer of the muscles of the forearm located at the back consists of the All muscles are innervated by the radial nerve or by branches of this nerve.

The supinator muscle, as its name suggests, is involved in the supination of the hand. This means it turns the palm upwards. It originates at the lateral epicondylus of the upper arm and runs from there diagonally to the forearm axis to the front surface of the radius.

The abductor pollicis longus muscle originates at the back of the ulna and radius and is attached to the base bone of the thumb. In the wrist, it causes flexion and abduction to the radius (radial). Its main function, however, is the extension and abduction of the thumb saddle joint.

The musculus abductor pollicis brevis originates at the back surface of the spoke and starts at the base of the thumb. It thus has the same function as the abductor pollicis longus muscle mentioned above.The Musculus extensor pollicis longus takes its origin at the back surface of the ulna and moves from there to the base of the thumb. Here it leads to the extension and adduction of the thumb.

The last muscle of this group is the muscle extensor indicies, which stretches the index finger. It originates at the back of the radius and starts at the base of the index finger.

  • Musculus supinator,
  • The musculus abductor pollicis longus,
  • Musculus extensor pollicis brevis and longus, and the
  • Musculus extensor indicis.