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Dumbbell Reverse Wrist Curl – Extension

It should be done in combination with the wrist curl to ensure equal development of the wrist flexor and wrist extensor muscles.

Holding a dumbbell in each hand, sit down and rest your elbows and forearms on your thighs, palms facing down. Elbows should be bent about 90-degrees and the dumbbells/hands should hang freely. Wrists are in line with the forearms.

Exhale and slowly roll your wrists to pull the weight up. Hold this position briefly.

Inhale and slowly bend at the wrist so that the dumbbells move toward the floor. Do not release your grip, straighten your elbows, or lean forward/backward. Repeat.


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Dumbbell Wrist Curl – Flexion

The wrist curl is a weight training exercise for developing the wrist flexor muscles of the forearm. It is therefore an isolation exercise. Ideally, it should be done in combination with the “reverse wrist curl” (also called wrist extension) to ensure equal development of the wrist flexor and wrist extensor muscles.

Holding a dumbbell in each hand, sit down and rest your elbows and forearms on your thighs, with your palms facing the ceiling. Elbows should be bent to about 90-degrees and the dumbbells/hands should hang freely. Wrists are in line with the forearms.

Inhale and slowly bend at the wrist so that the dumbbells to move toward the floor.

Exhale and slowly roll your wrists to pull the weight up and return the dumbbells to the starting position.


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The forgotten forearms (Posterior compartment)

Last but not least, the muscles located at the posterior compartment of the forearms.

Superficial posterior compartment

The extensor digitorum muscle helps in the movements of the wrists and the elbows. It extends the phalanges, then the wrist, and finally the elbow. It acts principally on the proximal phalanges. It tends to separate the fingers as it extends them.

Extensor digitorum

Origin:

  1. lateral epicondyle via the CET (common extensor tendon).
  2. antebrachial fascia.

Insertion:

  1. the base of middle phalanx of each of the four fingers (central band).
  2. the base of distal phalanx of each of the four fingers (2 lateral bands).

The extensor digiti minimi is a two joint muscle. It acts as an extensor in both joints. It extends the wrist, which means it moves the back of the hand toward the back of the forearm. It also extends the little finger, which means it straightens the little finger from a fist. When the muscle moves, it forces the little finger to bend and stretch. Sudden or unexpected movement of the finger or trauma may damage the muscle. Traction to keep the little finger from moving is typically recommended to treat the injury. Sprain of this muscle is common in athletes but is not considered to be a serious injury.

Extensor digiti minimi

Origin:

  1. lateral epicondyle via the CET (common extensor tendon).
  2. antebrachial fascia.
  3. the ulnar aspect of extensor digitorum.

Insertion:

  1. the base of middle phalanx of the 5th digit (central band).
  2. the base of distal phalanx of the 5th digit (2 lateral bands).

The extensor carpi ulnaris muscle allows the wrist, or carpus, to extend and bend. It works in conjunction with the flexor carpi ulnaris muscle during the adduction of the wrist, meaning when the wrist bends toward the body’s midline. However, it is the only muscle responsible for ulnar deviation. This refers to the movement of the hand sideways in the direction of the pinky. The extensor carpi ulnaris muscle is the primary muscle used when you accelerate your motorcycle.

Extensor carpi ulnaris

Origin:

  1. 1st head – lateral epicondyle via the CET (common extensor tendon).
  2. 2nd head – the posterior body of the ulna.
  3. antebrachial fascia.

Insertion:

medial side of the base of the 5th metacarpal.

A common injury to the extensor carpi ulnaris is tennis elbow. This injury occurs in people that participate in activities requiring repetitive arm, elbow, and wrist, especially when they are tightly gripping an object. Some symptoms include pain when shaking hands or when squeezing/gripping an object. The pain worsens when a person moves their wrist with force. The pain intensifies because the extensor carpi ulnaris has an injury near the elbow area and as a person moves their arm, the muscle contracts, thus causing it to move over the lateral epicondyle of the humerus. This causes irritation to the already existing injury.

The brachioradialis flexes the forearm at the elbow. It enables flexion of the elbow joint. The muscle also assists with pronation and supination of the forearm. These two movements allow the forearm and hand to turn so that the palm faces up or down. The arms are the only part of the body with this ability. The muscle is used to stabilize the elbow during rapid flexion and extension while in a mid position, such as in hammering.

Brachioradialis

Origin:

  1. the upper lateral supracondylar ridge of the humerus (between the triceps and brachialis muscles).
  2. the lateral intermuscular septum of the humerus.

Insertion:

  1. the superior aspect of the styloid process of the radius.
  2. the lateral side of the distal 1/2 to 1/3 of the radius.
  3. antebrachial fascia.

The extensor carpi radialis longus is a long muscle that connects the outside of the elbow to the bone at the base of the first finger. It extends the wrist and abducts the hand.

Extensor carpi radialis longus

Origin:

  1. lower lateral supracondylar ridge (below the brachioradialis).
  2. the lateral intermuscular septum of the humerus.

Insertion:

the base of 2nd metacarpal.

The extensor carpi radialis brevis muscle aids in moving the hand. Specifically, it abducts and extends the hand at the wrist joint. It is an extensor, and an abductor of the hand at the wrist joint. That is, it serves to manipulate the wrist so that the hand moves away from the palm and towards the thumb.

Extensor carpi radialis brevis

Origin:

  1. lateral epicondyle via the CET (common extensor tendon).
  2. radial collateral ligament.
  3. antebrachial fascia.

Insertion:

base of 3rd metacarpal.

Deep posterior compartment

Supinator consists of two planes of fibers, between which the deep branch of the radial nerve lies. Its function is to supinate the forearm. Supinator always acts together with biceps, except when the elbow joint is extended.

Supinator

Origin:

  1. lateral epicondyle of humerus.
  2. supinator crest of ulna.
  3. radial collateral ligament.
  4. annular ligament.
  5. antebrachial fascia.

Insertion:

the proximal portion of the anteriorlateral surface of the radius

The extensor indicis extends the index finger, and by its continued action assists in extending the wrist and the mid carpal joints. Because the index finger and little finger have separate extensors, these fingers can be moved more independently than the other fingers.

Extensor indicis

Origin:

  1. the posterior surface of ulna (distal to extensor pollicis longus).
  2. interosseous membrane.
  3. antebrachial fascia.

Insertion:

the base of the middle and distal phalanx of the index finger

The abductor pollicis longus muscle is one of three muscles in the forearm that facilitate the movements of the thumb. The others are the extensor pollicis brevis and extensor pollicis longus. These three muscles, along with the extensor indicis, make up the group of muscles called the deep extensors.The abductor pollicis longus lies immediately below the supinator and is sometimes united with it. The chief action of abductor pollicis longus is to abduct the thumb. It also assists in extending and rotating the thumb.

Abductor pollicis longus muscle

Origin:

  1. posterior surfaces of ulna and radius.
  2. interosseous membrane.
  3. antebrachial fascia.

Insertion:

lateral aspect of base of 1st metacarpal

The extensor pollicis brevis muscle is located on the dorsal side of the forearm. In a close relationship to the abductor pollicis longus, the extensor pollicis brevis both extends and abducts the thumb.

Abductor pollicis brevis muscle

Origin:

  1. posterior surfaces of radius (below abductor pollicis longus).
  2. interosseous membrane.
  3. antebrachial fascia.

Insertion:

the base of proximal phalanx of thumb (often a slip inserts into extensor pollicis longus tendon)

The extensor pollicis longus extends the terminal phalanx of the thumb. When moving the thumb, the muscle uses the radial tubercle as a pulley.

Extensor pollicis longus

Origin:

  1. posterior surface of ulna.
  2. interosseous membrane.
  3. antebrachial fascia.

Insertion:

distal phalanx of the thumb.

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The forgotten forearms (Anterior compartment)

The lower “arm” is called the forearm. The forearm contains many muscles, including the flexors and extensors of the digits, a flexor of the elbow (brachioradialis), and pronators and supinators that turn the hand to face down or upwards, respectively. In cross-section, the forearm can be divided into two fascial compartments. The posterior compartment contains the extensors of the hands, which are supplied by the radial nerve. The anterior compartment contains the flexors, and is mainly supplied by the median nerve. Let´s focus on this one.

Superficial anterior compartment

Pronator teres pronates the forearm, turning the hand posteriorly. If the elbow is flexed to a right angle, then pronator teres will turn the hand so that the palm faces inferiorly. It is assisted in this action by pronator quadratus.

It also weakly flexes the elbow, or assists in flexion at the elbow when there is strong resistance.

Pronator teres syndrome is one cause of wrist pain. It is a type of neurogenic pain.

  • Patients with the pronator teres syndrome have numbness in median nerve distribution with repetitive pronation/supination of the forearm, not flexion and extension of the elbow.
  • Early fatigue of the forearm muscles is seen with repetitive stressful motion, especially pronation.
  • EMG may show only mildly reduced conduction velocities.
  • despite their anatomic proximity, patients with pronator teres syndrome do not have a higher incidence of AIN syndrome.

Pronator teres

Origin:

  1. Humeral head:

A. upper portion of medial epicondyle via the CFT (common flexor tendon).

B. medial brachial intermuscular septum.

2. Ulnar head – coronoid process of ulna.

3. Antebrachial fascia.

Insertion:

Lateral aspect of radius at the middle of the shaft (pronator tuberosity).

Flexor carpi radialis is a muscle of the human forearm that acts to flex and (radial) abduct the hand. It is a superficial muscle that becomes very visible as the wrist comes into flexion. The flexor carpi radialis muscle is located close to the palm side of the arm, which allows it to bend the wrist on its side. This helps to reduce the angle between the forearm and the thumb. The wrist remains straight and does not extend or bend backwards.

Flexor carpi radialis

Origin:

  1. Medial epicondyle via the CFT (common flexor tendon).
  2. Antebrachial fascia.

Insertion:

Base of the 2nd and sometimes 3rd metacarpals

Palmaris longus serves no apparent function in humans.For this reason, it is actually very popular with reconstructive surgeons because they can “harvest” the tissue or the tendon and use it to rebuild other useful muscles. What is even more interesting is the fact that the muscle is completely or partially absent in about 14 percent of the population.

Palmaris longus

 Origin:

  1. Medial epicondyle via the CFT (common flexor tendon).
  2. Antebrachial fascia.

Insertion:

  1. Central portion of the flexor retinaculum.
  2. Superficial portion of the palmar aponeurosis.

The flexor carpi ulnaris muscle works in tandem with the extensor carpi ulnaris. These muscles flex the wrist and adduct it (move it laterally in the direction of ulnar).

Flexor carpi ulnaris

Origin:

  1. Humeral head – medial epicondyle via the CFT (common flexor tendon).
  2. Ulnar head:
  • Medial aspect of olecranon.
  • Proximal 3/5 of dorsal ulnar shaft.
  • Antebrachial fascia.

Insertion:

  1. Pisiform & hamate bones (via the pisohamate ligament).
  2. Base of the 5th metacarpal (via the pisometacarpal ligament).

The flexor digitorum superficialis is an extrinsic muscle that allows the four medial fingers of the hand to flex. It flexes the middle phalanges of the fingers at the proximal interphalangeal joints, however under continued action it also flexes the metacarpophalangeal joints and wrist joint. The secondary role of the muscle is to flex the metacarpophalangeal joints. These are located between the proximal phalanges and the metacarpal bones of the palm.

Flexor digitorum superficialis

Origin:

  1. Humeral-ulnar head:
  • Medial epicondyle via the CFT (common flexor tendon).
  • Medial boarder of base of coronoid process of ulna.
  • Medial (ulnar) collateral ligament.
  • Antebrachial fascia.

2. Radial head: oblique line of radius along its upper anterior boarder.

Insertion:

Both sides of the base of each middle phalanx of the 4 fingers

Deep anterior compartment

The pronator quadratus is a muscle that is near the lower part of the radius. It is the only muscle attached only to the radius at one end and the ulna at the other.

Its function is to rotate the forearm and keep the proper distance and rotation between the ulna and radius. It is also used to turn the wrist and palm of the hand. When pronator quadratus contracts, it pulls the lateral side of the radius towards the ulna, thus pronating the hand. Its deep fibers serve to keep the two bones in the forearm bound together.

Pronator quadratus

Origin:

Distal 1/4 anteriomedial surface of ulna.

Insertion:

Distal 1/4 anteriolateral surface of radius.

The flexor digitorum profundus belly is located in the forearm. However, it is considered a hand muscle because it is primarily used for hand functionality. The muscle’s long tendons extend over the wrist and the metacarpals of the hand.

It is a flexor of the wrist and helps flex the fingers.

Flexor digitorum profundus 2

Origin:

  1. Anterior & medial surface of upper 3/4 ulna.
  2. Adjacent interosseous membrane.

Insertion:

Distal phalanx of medial 4 digits (through FDS tunnel).

The flexor pollicis longus muscle is located in the lower half of the arm, from the elbow down. It is an anatomical part that is unique to humans.

The flexor pollicis longus is a flexor of the phalanges of the thumb; when the thumb is fixed, it assists by flexing the wrist.

Flexor pollicis longus

Origin:

  1. Middle anterior surface of the radius.
  2. Interosseous membrane.
  3. (may also originate from lateral boarder of coronoid process.
  4. or medial epicondyle).

Insertion:

Palmar aspect of base of the distal phalanx of thumb (deep to flexor retinaculum).