Muscles of the Forearm and Hand Flashcards
Extensor Carpi Radialis Longus and Brevis
O: Common extensor origin: lateral epicondyle of the
humerus
I: Base of 2nd metacarpal (ECRL),
I: Base of 3rd metacarpals (ECRB)
A: Wrist extension and Radial Deviation
Inv: Radial
Extensor Digitorum
O: Common extensor origin: lateral epicondyle of the
humerus
I: By four tendons, each to the base of the extensor mechanism and to the dorsal base of the proximal phalanx of the fingers
A: Extends the MCP joints, extends the IP joints of the second through fifth digits
Inv: Radial
Extensor Digiti Minimi
O: Ulnar side of the belly of the extensor digitorum
I: Tendon usually divides, joining the ulnar side of the tendon of the extensor digitorum
A: Extends the MCP joints, extends the IP joints of the little finger
Inv: Radial
Extensor Carpi Ulnaris
O: Common extensor origin: lateral epicondyle of the
humerus
I: Base of 5th metacarpal
A: Extension of wrist and ulnar deviation
Inv: Radial
Abductor Pollicis Longus
O: Posterior surface of the middle part of the radius
and ulna, and adjacent interosseous membrane
I: Base of 1st metacarpal
A: 1st digit ABD and extension at CMC joint
Inv: Radial
Extensor Pollicis Brevis
O: Posterior surface of the middle to distal parts of the radius and adjacent
I: Proximal phalanx of thumb
A: 1st digit extension at MCP, IP joints
Inv: Radial
Extensor Pollicis Longus
O: Posterior surface of the middle part of the ulna and adjacent interosseous membrane
I: Distal phalanx of thumb
A: 1st digit extension at MCP, IP joints
Inv: Radial
Extensor Indices
O: Posterior surface of the middle to distal part of the ulna and adjacent interosseous membrane
I: Tendon blends with the ulnar side of
the index tendon of the extensor digitorum
A: 2nd digit extension and wrist extension
Inv: Radial
Supinator
O: Lateral epicondyle of the humerus and supinator
crest of the ulna
I: Lateral surface of the proximal radius
A: Supination of forearm
Inv: Radial
Pronator Teres
O: Humeral head: medial epicondyle
Ulnar head: medial to the tuberosity of ulna
I: Lateral surface of the middle radius
A: Pronation of forearm, elbow flexion
Inv: Median
Flexor Carpi Radialis
O: Common flexor origin: medial epicondyle of the
humerus
I: 2nd and 3rd metacarpals
A: Wrist flexion, Radial deviation
Inv: Median
Flexor carpis Ulnaris
O: Humeral head: Common flexor origin- medial epicondyle of the humerus
Ulnar head: posterior border of the middle one third of the ulna
I: Pisiform bone, pisohamate and pisometacarpal ligaments, and palmar base of the fifth metacarpal
bone
A: Wrist flexion, Ulnar Deviation
Inv: Ulnar
Flexor Digitorum Superficialis
O: Humeroulnar head: common flexor origin, and
the medial side of coronoid process of the ulna
Radial head: oblique line just distal and lateral to the bicipital tuberosity
I: By four tendons, each to the sides of the middle phalanges of the fingers
A: Flexion of PIP joint of fingers
Inv: Median
Flexor Pollicis Longus
O: Middle part of the anterior surface of the radius and adjacent interosseous membrane
I: Distal phalanx of thumb
A: Flexion of distal phalanx of thumb
Inv: Median
Flexor Digitorum Profundus
O: Proximal 3/4 of the medial side of the ulna and
adjacent interosseous membrane
I: By four tendons, each to the palmar base of the distal phalanges of the fingers
A: Flex wrist, flex all joints to DIP in digits 2-5
Inv:
- Medial half: ulnar nerve
- Lateral half: median nerve
Pronator Quadratus
O: Anterior surface of distal ulna
I: Anterior surface of distal radius
A: Pronates forearm
Inv: Median
Abductor Pollicis Brevis
O: Palmar tubercles of the trapezium and scaphoid
I: Base of proximal phalanx of thumb
A: Abduction of thumb at MCP, CMC joint
Inv: Median
Flexor Pollicis Brevis
O: Transverse carpal ligament and palmar tubercle of trapezium
I: Radial side of proximal phalanx of thumb
A: Flexion of thumb
Inv: Median
Opponens Pollicis
O: Transverse carpal ligament and palmar tubercle of
trapezium
I: Shaft of the thumb metacarpal
A: Opposition of thumb
Inv: Median
Adductor Pollicis
O:
- Oblique head: capitate bone & base of second and
third metacarpal
- Transverse head: palmar surface of 3rd metacarpal
I: Ulnar side of the base of the proximal phalanx of the thumb
A: Adduction of thumb
Inv: Ulnar
Abductor Digiti Minimi
O: Pisiform bone, and tendon of the flexor carpi ulnaris
I: Base of the proximal phalanx of the
little finger
A: Abduction of the little finger at MCP joint
Inv: Ulnar
Flexor Digiti Minimi
O: Hook of the hamate
I: Base of the proximal phalanx of the little finger
A: Flexion of little finger
Inv: Ulnar
Opponens Digiti Minimi
O: Transverse carpal ligament & hook of the hamate
I: Shaft of the fifth metacarpal
A: Flexion of 5th metacarpal, lateral rotation producing opposition
Inv: Ulnar
Lumbricals of the hand
O:
- First and second: Radial
surface of the flexor
profundus tendons of the
index and middle fingers,
respectively.
- Third: Adjacent sides of the
flexor profundus tendons of
the middle and ring fingers.
- Fourth: Adjacent sides of
the flexor profundus
tendons of the ring and little
fingers
I: Into the radial border of the extensor
expansion on the dorsum of the respective digits
A: Flexion at MCP, Extension at IP
Inv:
- Medial two: ulnar nerve
- Lateral two: median nerve
Dorsal Interossei (DAB)
O:
First: adjacent sides of the first and second
metacarpal
Second: adjacent sides of the second and third
metacarpal
Third: adjacent sides of the third and fourth metacarpal
Fourth: adjacent sides of the fourth and fifth
metacarpal
I:
First: Radial side of the index finger, chiefly to the base of the proximal phalanx
Second: Radial side of the middle finger
Third: Ulnar side of the middle finger, chiefly into extensor expansion
Fourth: Ulnar side of the ring finger
A: Abduction of 2nd, 3rd, 4th digits away from middle finger
Inv: Ulnar
Palmar Interossei (PAD)
O:
First: ulnar side of the thumb metacarpal
Second: ulnar side of the second metacarpal
Third: radial side of the fourth metacarpal
Fourth: radial side of the fifth metacarpal
I:
First: Ulnar side of the thumb.
Second: Ulnar side of the index finger.
Third: Radial side of the ring finger.
Fourth: Radial side of the little finger.
A: Adduction of 2nd, 4th, 5th digits towards middle finger, flexion of digit at MCP, extension at IP
Inv: Ulnar
