Muscles of Forearm Flashcards
Boundaries of Cubital Fossa
Superiorly: an imaginary line connecting medial and lateral epicondyles
Medially: pronator teres
Laterally: brachioradialis
Floor: brachialis and supinator
Roof: cubital fascia and skin
Cubital Fossa Contents
- Brachial artery
- Biceps tendon
- Median nerve
- Radial nerve
- Median Cubital vein
- Medial and lateral cutaneous nerves
Superficial layer of Flexor Region
- Pronator teres
- Flexor Carpi radialis
- Palmaris longus
- Flexor carpi unlaris
Intermediate layer of Flexor Region
- Flexor digitorum superficialis
Deep layer of Flexor Region
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator quadratus
Pronator teres
Proximal: coronoid process of ulna
Distal: lateral surface of radius
Innervation: median nerve
Main action: pronates forearm
Flexor carpi radialis
Proximal: medial epicondyle of humerus
Distal: base of 2nd & 3rd metacarpals
Innervation: median nerve
Main action: flex ion and abduction of hand
Palmaris longus
Proximal: medial epicondyle
Distal: palmar aponeurosis
Innervation: median nerve
Main action: hand flexion and tenses palmar aponeurosis
Flexor carpi ulnaris
Proximal: olecranon process
Distal: pisiform, hook of hamate, 5th metacarpal
Innervation: ulnar nerve
Main action: adduction and flexion of hand at wrist
Flexor digitorum superficialis
Proximal: medial epicondyle, coronoid process of ulna and anterior radius
Distal: middle phalanges of medial four fingers (2-5)
Innervation: median nerve
Main action: flexion of proximal inter-phalangeal (PIP) joints of fingers 2-5
Flexor digitorum profundus
Proximal: ulna and interosseous membrane
Distal: base of digital phalanges of fingers (2-5)
Innervation: lateral part (finger 2,3) by median nerve; medial part (finger 4,5) by ulnar nerve [median nerve lies b/w FDS & FDP]
Main action: flexion of distal inter-phalangeal (DIP) joints of fingers 2-5
Flexor pollicis longus
Proximal: radius and interosseous membrane
Distal: base of distal phalanx of thumb
Innervation: anterior interosseous nerve (branch of median nerve)
Main action: thumb flexion
Pronator quadratus
Proximal: distal ulna
Distal: distal radius
Innervation: anterior interosseous nerve (branch of median)
Main action: probate forearm
Brachioradialis
Proximal: lateral supracondylar ridge of humerus
Distal: stylus process of radius
Innervation: radial nerve
Main action: weak flexion of elbow joint
Extensor carpi radialis longus and brevis
Proximal: lateral supracondylar ridge of humerus (longus) and laterally epicondyle (brevis)
Distal: base of 2nd (longus) and 3rd (brevis) metacarpal
Innervation: radial nerve
Main action: extend and abduction wrist joint
Extensor digitorum
Proximal: lateral epicondyle of humerus
Distal: extensor expansion of the medial four fingers 2-5
Innervation: posterior interosseous nerve (branch of radial nerve)
Main action: extends 2nd, 3rd, and 4th fingers
Extensor digiti minimi
Proximal: lateral epicondyle (common belly with extensor digitorum)
Distal: extensor expansion of 5th finger (pinky finger)
Innervation: posterior interosseous nerve (branch of radial)
Main action: extends wrist joint, extends 5th finger
Extensor carpi ulnaris
Proximal: lateral epicondyle of humerus
Distal: base of 5th metacarpal
Innervation: posterior interosseous nerve (branch of radial)
Main action: extends and adducts hand
Supinator
Short shiny muscle with diagonally running fibers
Proximal: lateral epicondyle of humerus
Distal: proximal radius
Innervation: radial nerve
Main action: supinates forearm
Extensor pollicis longus
Proximal: ulna, IM
Distal: base of distal phalanx of thumb
Innervation: posterior interosseous nerve (branch of radial)
Main action: extends distal phalanx of thumb
Extensor pollicis brevis
Proximal: distal radius, IM
Distal: base of proximal phalanx of thumb
Innervation: posterior interosseous nerve (branch of radial nerve)
Main action: extends proximal phalanx of thumb
Abductor pollicis longus
Proximal: ulna, radius, IM
Distal: base of 1st metacarpal
Innervation: posterior interosseous nerve (branch of radial nerve)
Main action: abduct thumb
Extensor indicis
Proximal: distal ulna, IM
Distal: extensor expansion of 2nd finger
Innervation: posterior interosseous nerve (radial)
Main action: extends 2nd finger
Extensor Superficial Layer
- Brachioradialis
- Extensor carpi radialis longus and brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
Extensor Deep Layer
- Supinator
- Extensor pollicis longus
- Extensor pollicis brevis
- Abductor pollicis longus
- Extensor indicis