Hand

What muscles make up the thenar eminence?

• Abductor pollicis brevis

• Flexor pollicis brevis

• Opponens pollicis

• Adductor pollicis

What muscles make up the hypothenar eminence?

• Abductor digital minimi

• Flexor digiti minimi

• Opponens digiti minimi

• Palmaris brevis

What muscles make up the deep palmar region?

Lumbricals, palmar interossei, dorsal interossei

What is the origin of the abductor pollicis brevis?

• Scaphoid

• Trapezium

• Flexor retinaculum

What is the insertion of the abductor pollicis brevis, adductor pollicis, and flexor pollicis brevis?

Base of proximal phalanx of 1st digit

What is the action of the abductor pollicis brevis?

Abducts the 1st digit

What is the innervation of the abductor pollicis brevis, flexor pollicis brevis, opponens pollicis?

Median nerve

What is the origin of the flexor pollicis brevis, opponens pollicis, flexor digit minimi, and opponens digiti minimi?

Flexor retinaculum

What is the insertion of the opponens pollicis?

Lateral shaft of the 1st metacarpal

What is the action of the opponens pollicis?

Opposes the 1st digit (moves thumb toward pinky)

What is the origin of the adductor pollicis?

Transverse head: shaft of 3rd metacarpal

Oblique head: bases of 2nd and 3rd metacarpals

What is the action of the adductor pollicis?

Adducts the 1st digit

What is the innervation of the adductor pollicis, abductor digiti minimi, flexor digiti minimi, opponens digiti minimi, palmaris brevis, and the palmar and dorsal interossei muscles?

Ulnar nerve

What is the neumonic to remember what muscles are innervated by the median nerve?

½ LOAF

What is the origin of the abductor digiti minimi?

Pisiform

What is the insertion for the abductor digiti minimi and the flexor digiti minimi?

Base of proximal phalanx of the 5th digit

What is the action of the abductor digiti minimi?

Abducts the 5th digit

What is the origin of the palmaris brevis

Flexor retinaculum and palmar aponeurosis

What is the action of the flexor digiti minimi?

Flexes the MCP joint of the 5th digit

What is the insertion of the opponens digiti minimi?

Medial shaft of the 5th metacarpal

What is the action of the opponens digiti minimi?

Opposes 5th digit

What is the insertion of the palmaris brevis?

Skin of palm

What is the action of the palmaris brevis?

Corrugates the skin (grip strength)

What is the origin of the 4 lumbrical muscles?

Tendons of the flexor digitorum profundus

What is the insertion of the lumbrical muscles?

Extensory hood of the 2nd through 5th digits

What is the action of the lumbrical muscles?

Primary: flexes the MCP joints of digits 2-5

Secondary: Extends MCP joints of digits 2-5

What is the innervation of the lumbrical muscles?

1st and 2nd=median nerve

3rd and 4th=ulnar nerve

What is the origin of the palmar interosseous muscles?

• medial shaft of 2nd metacarpal (1st)

• Lateral shaft of 3rd and 4th metacarpals (4 and 5)

What is the insertion of the palmar interossesous muscles?

extensor hood of 2nd, 4th, 5th digit

What is the action of the palmar interosseous muscles?

P: adducts the MCP joints of digits 2, 4, 5

S: flexes and extends MCP joints of 2, 4, 5

What is the origin of the dorsal interosseous muscles?

Shafts of 2-5 metacarpals

What is the insertion of the dorsal interosseous muscles?

Extensor hood of 2nd-4th digits

What is the action of the dorsal interosseous muscles?

P: abducts the MCP joints of 2-4

S: flexes MCP and extends IP joints of 2-4 digits