Forearm/Hand Joint Flashcards
Learn the OIAI of the forehand/hand joint
Extensor carpi radialis longus
Origin -
The inferior one third of the lateral supracondylar ridge of the humerus
The lateral intermuscular septum of the arm
Insertion- The dorsal aspect of the base of the second metacarpal bone
Action -Extends the hand at the wrist joint, Abducts the hand at the wrist and midcarpal joints
Innervation - The radial nerve
Extensor carpi radialis brevis
Origin -Lateral epicondyle of the humerus
Insertion-Dorsal aspect of the base of the third metacarpal bone
Action - Wrist extension and hand abduction
Innervation -Deep branch of the radial nerve
Extensor indicis
Origin -Posterior surface of the distal ulna and interosseous membrane
Insertion: Extensor expansion of the index finger
Action: Extends the index finger
Innervation: Posterior interosseous nerve (C7, C8)
Extensor digitorum
Origin - Lateral epicondyle of the humerus
Insertion: Dorsal surface of the middle and distal phalanges of digits 2-5 (index, middle, ring, and little fingers)
Action: Extends the fingers at the metacarpophalangeal and interphalangeal joints
Innervation: Posterior interosseous nerve (a branch of the radial nerve
Extensor digiti minimi
Origin: Lateral epicondyle of the humerus
Insertion: Extensor expansion of the little finger
Action: Extends the little finger
Innervation: Posterior interosseous nerve (C7, C8)
Extensor carpi ulnaris
Origin: Lateral epicondyle of the humerus and posterior border of the ulna
Insertion: Base of the fifth metacarpal bone
Action: Wrist extension and ulnar deviation (adduction)
Innervation: Posterior interosseous nerve (C7, C8)
Abductor pollicis longus
Origin - posterior surfaces of the radius and ulna bones
Insertion- lateral aspect of the base of the first metacarpal bone
Action - abducts the thumb and extends it at the carpometacarpal joint
Innervation -posterior interosseous nerve
Extensor pollicis brevis
Origin: Posterior surface of the distal radius and adjacent interosseous membrane
Insertion: Base of the proximal phalanx of the thumb
Action: Extends the thumb at the carpometacarpal and metacarpophalangeal joints
Innervation: Posterior interosseous nerve (C7, C8)
Extensor pollicis longus
Origin: Posterior surface of the middle third of the ulna and the interosseous membrane
Insertion: Base of the distal phalanx of the thumb
Action: Extends the thumb at the metacarpophalangeal and interphalangeal joints
Innervation: Posterior interosseous nerve (a branch of the radial nerve)
Flexor carpi radialis
Origin: Medial epicondyle of the humerus
Insertion: Base of the second and third metacarpal bones
Action: Wrist flexion and radial deviation (hand abduction)
Innervation: Median nerve (C6-C7)
Palmaris longus
Origin - medial epicondyle of the humerus.
Insertion- palmar aponeurosis and the distal half of the flexor retinaculum.
Action - flexes the hand at the wrist
Innervation - median nerve (C7, C8)
Flexor carpi ulnaris
Origin: Medial epicondyle of humerus (humeral head), olecranon and posterior border of ulna (ulnar head)
Insertion: Pisiform bone, hook of hamate, and base of the 5th metacarpal bone
Action: Wrist flexion and adduction
Innervation: Ulnar nerve (C7-T1)
Flexor digitorum superficialis
Origin -
Humeroulnar head: Medial epicondyle of humerus, coronoid process of ulna
Radial head: Proximal half of anterior border of radius
Insertion- Sides of middle phalanges of digits 2-3
Action -flexes the proximal interphalangeal (PIP) and metacarpophalangeal (MCP)
Innervation - the median nerve
Flexor pollicis longus
Origin: The anterior surface of the radius and the interosseous membrane of the forearm
Insertion: The palmar aspect of the base of the thumb’s distal phalanx
Action: Flexes the thumb’s interphalangeal and metacarpophalangeal joints. It may also help flex the wrist
Innervation: The anterior interosseous nerve, which comes from the median nerve
Flexor digitorum profundus
Origin - Proximal half of anterior surface of ulna, interosseous membrane
Insertion-Palmar surfaces of distal phalanges of digits 2-5
Action -Metacarpophalangeal and interphalangeal joints 2-5: Finger flexion
Innervation -
The medial part of the FDP is innervated by the ulnar nerve
The lateral part of the FDP is innervated by the anterior interosseous branch of the median nerve
Interossei (palmer/dorsal)
Origin: Lateral and medial surfaces of the metacarpal bones.
Insertion: Base of the proximal phalanx and extensor expansion of the finger.
Action:
Palmar Interossei: Adduction of fingers
Dorsal Interossei: Abduction of fingers
Innervation: Deep branch of the ulnar nerve
Lumbricals
Origin: Tendons of the flexor digitorum profundus
Insertion: Radial aspect of the extensor expansions of the fingers
Action: Flexion at the metacarpophalangeal joint, extension at the interphalangeal joints
Innervation:
Lateral two lumbricals: Median nerve
Medial two lumbricals: Deep branch of the ulnar nerve
Adductor pollicis
Origin - ransverse head: Palmar base of metacarpal bone 3
Oblique head: Capitate bone, palmar bases of metacarpal bones 2 & 3
Insertion- Medial base of proximal phalanx 1
Action - Thumb adduction
Innervation - deep branch of the ulnar nerve
Adductor pollicis brevis
Origin - Tubercles of scaphoid and trapezium bones
Insertion- Lateral aspect of base of proximal phalanx 1
Action -Thumb abduction
Innervation - recurrent branch of the medial nerve
Opponens pollicis
Origin: Tubercle of trapezium bone and flexor retinaculum
Insertion: Lateral side of the first metacarpal bone
Action: Thumb opposition
Innervation: Recurrent branch of the median nerve
Flexor pollicis brevis
Origin -
Superficial head: Flexor retinaculum, tubercle of trapezium bone
Deep head: Trapezoid and capitate bones
Insertion-Lateral aspect of base of proximal phalanx 1
Action -Thumb flexion
Innervation - Superficial head: Recurrent branch of median nerve
Deep head: Deep branch of ulnar nerve (C8, T1)
Abductor digiti minimi
Origin: Pisiform bone and flexor carpi ulnaris tendon
Insertion: Medial side of the base of the proximal phalanx of the little finger
Action: Abducts the little finger
Innervation: Deep branch of the ulnar nerve (C8-T1)
Flexor digiti minimi brevis
Origin: Hook of hamate bone and flexor retinaculum
Insertion: Medial side of the base of the proximal phalanx of the little finger
Action: Flexion of the little finger at the metacarpophalangeal joint
Innervation: Deep branch of the ulnar nerve
Opponens digiti minimi
Origin - Hook of hamate bone, flexor retinaculum
Insertion- Ulnar aspect of metacarpal bone 5
Action - Finger flexion, finger lateral rotation/opposition
Innervation - Deep branch of ulnar nerve (C8, T1)
