Elbow and hand overview muscles edited

Page 1: Muscle Actions and Innervations

  • Brachialis

    • Origin: Anterior surface of distal half of humerus

    • Insertion: Ulnar tuberosity and coronoid process of ulna

    • Action: Elbow flexion

    • Innervation: Musculocutaneous nerve (C5, C6)

  • Triceps Brachii

    • Origin:

      • Long head: Infraglenoid tubercle of scapula

      • Lateral head: Inferior to greater tubercle on posterior humerus

      • Medial head: Posterior surface of humerus

    • Insertion: Olecranon process of ulna

    • Action: Shoulder extension, elbow extension

    • Innervation: Radial nerve (C6, C7, C8)

  • Supinator

    • Origin: Lateral epicondyle of humerus and adjacent ulna

    • Insertion: Anterior surface of the proximal radius

    • Action: Forearm supination, elbow flexion

    • Innervation: Radial nerve (C6)

Page 2: Additional Muscle Functions

  • Brachioradialis

    • Origin: Lateral supracondylar ridge on humerus

    • Insertion: Distal lateral aspect of the radius

    • Action: Elbow flexion, forearm supination and pronation

    • Innervation: Radial nerve (C5, C6)

  • Pronator Teres

    • Origin: Medial epicondyle of humerus and coronoid process of ulna

    • Insertion: Lateral aspect of radius at its midpoint

    • Action: Forearm pronation, elbow flexion

    • Innervation: Median nerve (C6, C7)

  • Pronator Quadratus

    • Origin: Anterior distal one-fourth of ulna

    • Insertion: Anterior distal one-fourth of radius

    • Action: Forearm pronation

    • Innervation: Median nerve (C8, T1)

Page 3: Arm Muscles

  • Biceps Brachii

    • Origin:

      • Long head: Supraglenoid tubercle of scapula

      • Short head: Coracoid process of scapula

    • Insertion: Radial tuberosity of radius

    • Action: Shoulder flexion, elbow flexion, forearm supination

    • Innervation: Musculocutaneous nerve (C5, C6)

  • Anconeus

    • Origin: Lateral epicondyle of humerus

    • Insertion: Lateral and inferior to triceps on the olecranon process

    • Action: Elbow extension

    • Innervation: Radial nerve (C6, C7, C8)

Page 4: Wrist Flexors

  • Flexor Carpi Ulnaris

    • Origin: Medial epicondyle of humerus via common flexor tendon

    • Insertion: Pisiform and base of 5th metacarpal

    • Action: Combined wrist flexion and ulnar deviation

    • Innervation: Ulnar nerve (C8, T1)

  • Flexor Carpi Radialis

    • Origin: Medial epicondyle of humerus via common flexor tendon

    • Insertion: Base of 2nd and 3rd metacarpals

    • Action: Combined wrist flexion and radial deviation

    • Innervation: Median nerve (C6, C7)

  • Palmaris Longus

    • Origin: Medial epicondyle of humerus (via common flexor tendon)

    • Insertion: Palmar aponeurosis

    • Action: Wrist flexion

    • Innervation: Median nerve (C6, C7)

Page 5: Wrist Extensors

  • Extensor Carpi Radialis Longus

    • Origin: Lateral supracondylar ridge of humerus

    • Insertion: Base of 2nd metacarpal

    • Action: Combined wrist extension and radial deviation

    • Innervation: Radial nerve (C6, C7)

  • Extensor Carpi Radialis Brevis

    • Origin: Lateral epicondyle of humerus via common extensor tendon

    • Insertion: Base of 3rd metacarpal

    • Action: Wrist extension

    • Innervation: Radial nerve (C6, C7)

  • Extensor Carpi Ulnaris

    • Origin: Lateral epicondyle of humerus via common extensor tendon

    • Insertion: Base of 5th metacarpal

    • Action: Combined wrist extension and ulnar deviation

    • Innervation: Radial nerve (C6, C7, C8)

Page 6: Flexor Muscles of Hand

  • Flexor Digitorum Superficialis

    • Origin: Common flexor tendon, medial epicondyle, coronoid process and radius

    • Insertion: Side of the middle phalanx of the four fingers

    • Action: Wrist flexion, MCP and PIP flexion

    • Innervation: Median nerve (C7, C8, T1)

  • Flexor Digitorum Profundus

    • Origin: Coronoid process and proximal three-fourths of the ulna

    • Insertion: Distal phalanx of the four fingers

    • Action: Flexes all 3 joints of the fingers (DIPs, PIPs, and MCPs): wrist flexion

    • Innervation: Median and ulnar nerves (C8, T1)

Page 7: Thumb Flexors and Abductors

  • Flexor Pollicis Longus

    • Origin: Anterior surface of radius, interosseous membrane

    • Insertion: Distal phalanx of thumb

    • Action: Flexes CMC, MCP and IP joints of thumb

    • Innervation: Median nerve (C8, T1)

  • Abductor Pollicis Longus

    • Origin: Posterior middle portions of radius, ulna, and interosseous membrane

    • Insertion: Base of the first (thumb) metacarpal

    • Action: Abducts CMC joint of the thumb; extends CMC and MCP joints of thumb

    • Innervation: Radial nerve (C6, C7)

  • Extensor Pollicis Brevis

    • Origin: Posterior distal radius and interosseous membrane

    • Insertion: Base of the proximal phalanx of thumb

    • Action: Extends MCP and CMC joints of thumb

    • Innervation: Radial nerve (C6, C7)

Page 8: Thumb Extensors

  • Extensor Pollicis Longus

    • Origin: Posterior middle portions of ulna and interosseous membrane

    • Insertion: Base of distal phalanx of thumb

    • Action: Extends the CMC, MCP, and IP joints of the thumb

    • Innervation: Radial nerve (C6, C7, C8)

  • Extensor Digitorum

    • Origin: Lateral epicondyle of humerus

    • Insertion: Base of distal phalanx of the 2nd through 5th fingers

    • Action: Extends wrist, extends MCP, PIP, and DIP joints of the four fingers

    • Innervation: Radial nerve (C6, C7, C8)

  • Extensor Indicis

    • Origin: Distal ulna

    • Insertion: Base of distal phalanx of 2nd finger

    • Action: Extends all three joints of the second finger (DIP, PIP, MCP)

    • Innervation: Radial nerve (C6, C7, C8)

Page 9: Little Finger and Intrinsic Hand Muscles

  • Extensor Digiti Minimi

    • Origin: Lateral epicondyle of humerus via common extensor tendon

    • Insertion: Base of distal phalanx of little finger

    • Action: Extends all MCP, PIP and DIP joints of little finger

    • Innervation: Radial nerve (C6, C7, C8)

  • Flexor Pollicis Brevis

    • Origin: Trapezium and flexor retinaculum

    • Insertion: Proximal phalanx of the thumb

    • Action: Flexes the MCP and CMC joints of thumb

    • Innervation: Median nerve (C6, C7)

  • Abductor Pollicis Brevis

    • Origin: Scaphoid, trapezium, and flexor retinaculum

    • Insertion: Proximal phalanx of the thumb

    • Action: Abducts the thumb (CMC joint)

    • Innervation: Median nerve (C6, C7)

Page 10: Hypothenar Functions

  • Opponens Pollicis

    • Origin: Trapezium and flexor retinaculum

    • Insertion: First metacarpal

    • Action: Thumb opposition (CMC)

    • Innervation: Median nerve (C6, C7)

  • Flexor Digiti Minimi

    • Origin: Hamate and flexor retinaculum

    • Insertion: Base of proximal phalanx of the fifth finger

    • Action: Flexes MCP and CMC joints of the fifth finger

    • Innervation: Ulnar nerve (C8, T1)

  • Opponens Digiti Minimi

    • Origin: Hamate and flexor retinaculum

    • Insertion: 5th metacarpal

    • Action: Opposes little finger (CMC joint)

    • Innervation: Ulnar nerve (C8, T1)

  • Abductor Digiti Minimi

    • Origin: Pisiform and tendon of flexor carpi ulnaris

    • Insertion: Proximal phalanx of little finger

    • Action: Abducts the MCP joint of the little finger

    • Innervation: Ulnar nerve (C8, T1)

Page 11: Deep Palmar Intrinsics

  • Adductor Pollicis

    • Origin: Capitate, bases of 2nd and 3rd metacarpals, and distal two-thirds of the palmar surface of the 3rd metacarpal

    • Insertion: Base of proximal phalanx of thumb

    • Action: Adducts thumb (CMC joint)

    • Innervation: Ulnar nerve (C8, T1)

  • Dorsal Interossei

    • Origin: Adjacent metacarpals

    • Insertion: Base of proximal phalanges of index, middle, and ring fingers

    • Action: Abduct fingers at MCP joint

    • Innervation: Ulnar nerve (C8, T1)

  • Palmar Interossei

    • Origin: 2nd, 4th, and 5th metacarpals

    • Insertion: Base of respective proximal phalanx

    • Action: Adduct index, ring, and middle fingers at MCP joint

    • Innervation: Ulnar nerve (C8, T1)

Page 12: Lumbricals

  • Lumbricals

    • Origin: Tendon of the flexor digitorum profundus muscle

    • Insertion: Tendon of the extensor digitorum muscle

    • Action: Simultaneous flexion of the MCP and extension of the PIP and DIP joints of each of the four fingers.

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