Intrinsic Muscles of the Hand Flashcards
4 Lumbricals
4 tendons of the Flexor Digitorum Profundus in the palm
Extensor expansion at the proximal phalanges and tendons of Extensor Digitorum
Median (lateral 2)
Ulnar (medial 2)
Extends IP joints assists in MCP flexion
3 Palmar Interossei
O:
Anterior aspect of the shafts of the 2nd, 4th and 5th metacarpals
I:
Dorsal Extensor expansion and palmar base of the proximal phalanges
In:
Ulnar
F:
ADducts index, ring, and little finger, flexes MCP and extends IP joints
4 Dorsal Interossei
O:
Adjacent sides of all 5 metacarpals
I:
Base of the proximal phalanx and extensor expansion: both sides of the middle finger, radial side of the index and ulnar side of the ring finger
In:
Ulnar
F:
Extends IP joints, flexes MCP joints, ABducts from midline of the middle finger
Abductor Digiti Minimi
O:
Pisiform
I:
Ulnar side on the base of the proximal phalanx of the little finger
In:
Ulnar
F:
Abduction of the little finger at the MCP joint
Flexor Digiti Minimi
O:
Flexor retinaculum
I:
Anterior medial aspect of proximal phalanx of little finger
In:
Ulnar
F:
Flexion of little finger at MCP joint
Opponens Digiti MInimi
O:
Flexor retinaculum
I:
Entire medial border of 5th metacarpal
In:
Ulnar
F:
Opposition of little finger
Assists in flexion of the CMC joint
Abductor Pollicis Brevis
O:
Flexor Retinaculum, scaphoid and trapezium
I:
Radial side of the base of the first phalanx
In:
Median
F:
Abduction of the thumb and CMC and MCP joints and flexion at the MCP
Flexor Pollicis Brevis
O:
Flexor retinaculum
I:
Radial side of the base of the 1st proximal phalanx
In:
Median
F:
Flexion of thumb’s MCP joint, ADduction and opposition
Opponens Pollicis
O:
Flexor retinaculum
I:
Radial side of the shaft of the 1st metacarpal
In:
Median
F:
Opposition of the thumb
Adductor Pollicis
O:
Anterior aspect of the 2nd and 3rd metacarpal and adjoining carpal bones
I:
Medial palmar side of base of 1st proximal phalanx
In:
Ulnar
F:
Thumb adduction of CMC and MCP joints, assists in flexion of MCP joint
