Upper Extremity Muscles

  1. Flexor pollicis longus
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    Origin: middle 1/2 of the anterior surface of the radius

    Insertion: The base of the distal phalanx of the thumb

    Function: Flexion of the thumb

    Nerve: Anterior interosseous nerve (branch of median nerve) (C8, T1)
  2. Flexor pollicis brevis
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    Origin: trapezium, flexor retinaculum

    Insertion: thumb, proximal phalanx

    Function: Flexes the thumb at the first metacarpophalangeal joint

    Nerve: Recurrent branch of the median nerve, deep branch of ulnar nerve (medial head)
  3. Opponens pollicis
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    Origin: trapezium and transverse carpal ligament

    Insertion: metacarpal bone of the thumb on its radial side

    Function: Flexion of the thumb's metacarpal at the first carpometacarpal joint, which aids in opposition of the thumb

    Nerve: Recurrent branch of the median nerve
  4. Abductor pollicis longus
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    Origin: ulna, radius, Interosseous membrane

    Insertion: 1st metacarpal

    Function: abduction, extension of thumb

    Nerve: Posterior interosseous nerve from deep branch of radial nerve C7, C8
  5. Abductor pollicis brevis
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    Origin: Transverse carpal ligament, the scaphoid and trapezium

    Insertion: Radial base of proximal phalanx of thumb and the thumb extensors

    Function: Abduction of the thumb by acting across the carpometacarpal joint and the metacarpophalangeal joint. It also assists in opposition and extension of the thumb

    Nerve: Recurrent branch of the median nerve
  6. Palmar interosseus
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    Origin: Sides of metacarpals facing midline

    Insertion: Bases of proximal phalanges, extensor expansions

    Function: Adduction, flexion and extension

    Nerve: Deep branch of ulnar nerve
  7. Dorsal interossei
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    Origin: Metacarpals

    Insertion: Proximal phalanges and extensor expansions

    Function: Abduct finger

    Nerve: Deep branch of ulnar nerve
  8. Flexor digitorum profundus
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    Origin: upper 3/4 of the anterior and medial surfaces of the body of the ulna, interosseous membrane and deep fascia of the forearm

    Insertion: base of the distal phalanges of the fingers

    Function: flex hand and both interphalangeal joints

    Nerve: median (anterior interosseous), muscular branches of ulnar
  9. Flexor digitorum superficialis
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    Origin: medial epicondyle of the humerus (common flexor tendon) as well as parts of the radius and ulna

    Insertion: anterior margins on the base of the middle phalanges of the four fingers

    Function: flexor of fingers (primarily at proximal interphalangeal joints)

    Nerve: median nerve
  10. Lumbricales manus
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    Origin: flexor digitorum profundus

    Insertion: extensor expansion

    Function: flex metacarpophalangeal joints, extend interphalangeal joints

    Nerve: Third and fourth deep branch of ulnar nerve, first and second median nerve
  11. Flexor digiti minimi brevis
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    Origin: hamate bone

    Insertion: palmar side of the base of the proximal phalanx of fifth digit

    Function: flexes little finger

    Nerve: deep branch of ulnar nerve
  12. Opponens digiti minimi
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    Origin: Hook of hamate and flexor retinaculum

    Insertion: Lateral border of 5th metacarpal (in hand, 3rd digit is orientation of mid-line)

    Function: Draws 5th metacarpal anteriorly and rotates it, bringing little finger (5th digit) into opposition with thumb

    Nerve: deep branch of ulnar nerve (C8 and T1)
  13. Palmaris brevis
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    Origin: Flexor retinaculum (medial) and palmar aponeurosis

    Insertion: Palm

    Function: Pulls on skin over hypothenar eminence, deepening the cup of the palm and so improving grip

    Nerve: Superficial branch of ulnar nerve
  14. Palmaris longus
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    Origin: medial epicondyle of humerus (common flexor tendon)

    Insertion: palmar aponeurosis and flexor retinaculum of the hand

    Function: wrist flexor

    Nerve: median nerve
  15. Flexor carpi ulnaris
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    Origin: Medial epicondyle (common flexor tendon) and medial margin on olecranon of ulna

    Insertion: Pisiform, hook of the hamate, base of the fifth metacarpal bone (Volar Aspect)

    Function: Flexion and adduction of wrist

    Nerve: Muscular branches of ulnar nerve (from C8 and T1)
  16. Flexor carpi radialis
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    Origin: medial epicondyle of humerus (common flexor tendon)

    Insertion: Bases of second and third metacarpal bones

    Function: Flexion and abduction at wrist

    Nerve: Median nerve
  17. Biceps brachii
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    Origin: Short head: coracoid process of the scapula.Long head: supraglenoid tubercle

    Insertion: Radial tuberosity and bicipital aponeurosis into deep fascia on medial part of forearm

    Function: Flexes elbowflexes and abducts shoulder supinates radioulnar joint in the forearmFlexion and abduction at wrist

    Nerve: Musculocutaneous nerve (C5–C7)
  18. Supinator
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    Origin: Lateral epicondyle of humerus, supinator crest of ulna, radial collateral ligament, annular ligament

    Insertion: Lateral proximal radial shaft

    Function: Supinates forearm

    Nerve: Deep branch of the radial nerve
  19. Brachoradialis
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    Origin: Lateral supracondylar ridge of the humerus

    Insertion: Distal radius (radial styloid process)

    Function: Flexion of elbow, supination and pronation of the radioulnar joint to 90°

    Nerve: Radial nerve
  20. Brachialis
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    Origin: anterior surface of the humerus, particularly the distal half of this bone

    Insertion: coronoid process and the tuberosity of the ulna

    Function: flexion at elbow joint

    Nerve: musculocutaneous nerve (C5-C7) and radial nerve (C5, C6)
  21. Coracobrachialis
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    Origin: Coracoid process of scapula

    Insertion: Anteromedial surface of humerus distal to crest of lesser tubercle

    Function: adducts humerus, flexes the arm at glenohumeral joint

    Nerve: Musculocutaneous nerve (C5, C6, and C7)
  22. Deltoid
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    Origin: the anterior border and upper surface of the lateral third of the clavicle, acromion, spine of the scapula

    Insertion: deltoid tuberosity of humerus

    Function: shoulder abduction, flexion and extension

    Nerve: Axillary nerve
  23. Supraspinatus
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    Origin: supraspinous fossa of scapula

    Insertion: deltoid tuberosity of humerus

    Function: abduction of arm and stabilizes humerus see part on controversy of action

    Nerve: suprascapular nerve C5-C6
  24. 6. Teres minor
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    Origin: lateral border of the scapula

    Insertion: greater tubercle of the humerus

    Function: laterally rotates the arm, stabilizes humerus

    Nerve: axillary nerve (C5-C6)
  25. 8 Infraspinatus
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    Origin: infraspinous fossa of the scapula

    Insertion: middle facet of greater tubercle of the humerus

    Function: External rotation of arm and stabilization of glenohumeral joint

    Nerve: suprascapular nerve
  26. Serratus anterior
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    Origin: fleshy slips from the outer surface of upper 8 or 9 ribs

    Insertion: costal aspect of medial margin of the scapula

    Function: protracts and stabilizes scapula, assists in upward rotation

    Nerve: long thoracic nerve (from roots of brachial plexus C5, 6, 7)
  27. Trapezius
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    Origin: external occipital protuberance, spinous processes of vertebrae C7-T12, Nuchal ligament, Occipital BoneMedial one-third of superior nuchal line External occipital protuberance Ligamentum nuchae T1-T12 spine. Corresponding supraspinous ligaments

    : nuchal ligament, medial superior nuchal line, posterior border of the lateral one-third of the clavicle, acromion process, and spine of scapula

    Function: Rotation, retraction, elevation, and depression of scapula

    Nerve: accessory nerve (motor)cervical spinal nerves C3 and C4 (motor and sensation)
  28. Extensor pollicis brevis
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    Origin: radius and the interosseous membrane

    Insertion: thumb, proximal phalanx

    Function: extension of thumb at metacarpophalangeal joint

    Nerve: posterior interosseous nerve
  29. Extensor pollicis longus
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    Origin: Middle third of posterior surface of ulna, interosseous membrane

    Insertion: thumb, distal phalanx

    Function: extension of the thumb (metacarpophalangeal and interphalangeal)

    Nerve: posterior interosseous nerve (branching from the radial nerve)
  30. Adductor pollicis
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    Origin: Transverse head: anterior body of the third metacarpalOblique head: bases of the second and the third metacarpals and the adjacent trapezoid and capitate bones

    Insertion: medial side of the base of the proximal phalanx of the thumb and the ulnar sesamoid

    Function: adducts the thumb at the carpometacarpal joint

    Nerve: deep branch of the ulnar nerve (T1)
  31. Palmar interrosei
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    Origin: Transverse head: anterior body of the third metacarpalOblique head: bases of the second and the third metacarpals and the adjacent trapezoid and capitate bones

    Insertion: medial side of the base of the proximal phalanx of the thumb and the ulnar sesamoid

    Function: adducts the thumb at the carpometacarpal joint

    Nerve: deep branch of the ulnar nerve (T1)
  32. Dorsal interrosei
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    Origin: Metacarpals

    Insertion: Proximal phalanges and extensor expansions

    Function: Abduct finger

    Nerve: Deep branch of ulnar nerve
  33. Abductor digiti minimi
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    Origin: Pisiform bone, the pisohamate ligament, and the flexor retinaculum

    Insertion: Base of the proximal phalanx of the 5th digit on the ulnar or medial side

    Function: Abducts little finger

    Nerve: Deep branch of ulnar nerve
  34. Extensor digitorum
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    Origin: lateral epicondyle (common extensor tendon)

    Insertion: extensor expansion of middle and distal phalanges of the 2nd, 3rd, 4th, and 5th fingers

    Function: extension of hand, wrist and fingers

    Nerve: posterior interosseous nerve
  35. Extensor pollicis et indicis communis
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    Origin: Posterior distal third of ulna and interosseous membrane

    Insertion: thumb (extensor hood) and index finger (extensor hood)

    Function: extension of hand, wrist and fingers

    Nerve: posterior interosseous nerve
  36. Extensor carpi radialis longus
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    Origin: lateral supracondylar ridge

    Insertion: 2nd metacarpal

    Function: extensor at the wrist joint, abducts the hand at the wrist

    Nerve: radial nerve
  37. Extensor carpi radialis brevis
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    Origin: humerus at the anterior of lateral epicondyle (common extensor tendon)

    Insertion: Posterior base of the 3rd metacarpal

    Function: extensor and abductor of the hand at the wrist joint

    Nerve: deep branch of the radial nerve
  38. Extensor carpi ulnaris
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    Origin: Humeral head: Lateral epicondyle of the Humerus.Ulnar head: Olecranon, Posterior surface of ulna, antebrachial fascia

    Insertion: 5th metacarpal

    Function: extends and adducts the wrist

    Nerve: Deep branch of the radial nerve (C7, C8)
  39. Pronator quadratus
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    Origin: medial, anterior surface of the ulna

    Insertion: lateral, anterior surface of the radius

    Function: pronates the forearm

    Nerve: median nerve (anterior interosseous nerve)
  40. Pronator teres
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    Origin: humeral head: medial supracondylar ridge of humerus (common flexor tendon), ulnar head:coronoid process of ulna

    Insertion: lateral, anterior surface of the radius

    Function: pronates the forearm

    Nerve: median nerve (anterior interosseous nerve)
  41. Triceps brachii
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    Origin: Long head: infraglenoid tubercle of scapula. Lateral head: above the radial groove. Medial head: below the radial groove

    Insertion: Olecranon process of ulna

    Function: Extends forearm, long head extends, adducts arm, Extends shoulder

    Nerve: Radial nerve and Axillary nerve
  42. Aconeus
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    Origin: lateral epicondyle of the humerus proximally

    Insertion: lateral surface of the olecranon process of the radial and the superior proximal part of the posterior ulna

    Function: It is partly blended in with the triceps, which it assists in extension of the forearm. It also stabilizes the elbow during pronation and supination and pulls slack out of the elbow joint capsule during extension to prevent impingement

    Nerve: radial nerve (C5, C6, C7, C8, and T1)
  43. Latissimus dorsi
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    Origin: Spinous processes of T6-T12 and L1-L5, thoracolumbar fascia, iliac crest, sacrum, inferior 4 ribs and inferior angle of scapula

    Insertion: intertubercular groove of the humerus

    Function: Adducts, extends and internally rotates the arm when the insertion is moved towards the origin. When observing the muscle action of the origin towards the insertion, the lats are a very powerful rotator of the trunk.

    Nerve: Thoracodorsal nerve (C6, C7, C8)
  44. Pectoralis major
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    Origin: Clavicular head: anterior surface of the medial half of the clavicle. Sternocostal head: anterior surface of the sternum, the superior six costal cartilages, and the aponeurosis of the external oblique muscle

    Insertion: Lateral lip of the bicipital groove of the humerus(anteromedial proximal humerus)

    Function: Clavicular head: flexes the humerus. Sternocostal head: horizontal and vertical adduction, extension, and internal rotation of the humerusDepression and abduction of the scapula

    Nerve: lateral pectoral nerve and medial pectoral nerve. Clavicular head: C5 and C6. Sternocostal head: C7, C8 and T1
  45. Pectoralis minor
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    Origin: Third to fifth ribs, near the costochondral junction

    Insertion: Medial border and superior surface of the coracoid process of the scapula

    Function: Stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall, raises ribs in inspiration

    Nerve: Medial pectoral nerve (C8)
  46. Teres major
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    Origin: Posterior aspect of the inferior angle of the scapula

    Insertion: Medial lip of the intertubercular sulcus of the humerus

    Function: adduct the humerus, Internal rotation (medial rotation) of the humerus, extend the humerus from flexed position, Depress shoulder

    Nerve: Lower subscapular nerve (segmental levels C5 and C6)
  47. Subscapularis
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    Origin: Subscapular fossa

    Insertion: Lesser tubercle of humerus

    Function: Internally rotates and adducts humerus; stabilizes shoulder

    Nerve: Upper subscapular nerve, lower subscapular nerve (C5, C6)
  48. Rhomboids
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    Origin: nuchal ligaments, spinous processes of the C7 to T5 vertebrae

    Insertion: medial border of the scapula

    Function: Pulls scapulae medially, rotates scapulae, Holds scapluae into thorax wall

    Nerve: dorsal scapular nerve
  49. Levator scapulae
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    Origin: Posterior tubercles of transverse processes of C1 - C4 vertebrae

    Insertion: Superior part of medial border of scapula

    Function: Pulls scapulae medially, rotates scapulae, Holds scapluae into thorax wall

    Nerve: cervical nerve (C3, C4) and dorsal scapular nerve (C5)
Card Set
Upper Extremity Muscles
origin, insertions, function, innervation