Wrist and Hand - MOINA

Muscles in the Thenar Compartment

• Abductor pollicis brevis

• Flexor pollicis brevis

• Opponens pollicis

Muscles in the Hypothernar Compartment

• Abductor digiti minimi

• Flexor digiti minimi brevis

• Opponens digiti minimi

Origin of Abductor Pollicis Brevis

Flexor retinaculum, scaphoid, trapezium

Insertion of Abductor Pollicis Brevis

Lateral side of base of proximal phalanx of thumb

Nerve Supply of Abductor Pollicis Brevis

Recurrent branch of median nerve

Action of Abductor Pollicis Brevis

Abducts thumb

Origin of Flexor Pollicis Brevis

Flexor retinaculum, trapezium

Insertion of Flexor Pollicis Brevis

Nerve Supply of Flexor Pollicis Brevis

Superficial head: Median nerve

Deep head: Ulnar nerve

Action of Flexor Pollicis Brevis

Flexes thumb at MCP joint

Origin of Opponens Pollicis

Flexor retinaculum, trapezium

Insertion of Opponens Pollicis

Lateral side of 1st metacarpal

Nerve Supply of Opponens Pollicis

Recurrent branch of median nerve

Action of Opponens Pollicis

Opposes thumb (medial rotation)

Origin of Abductor Digiti Minimi

Pisiform bone

Insertion of Abductor Digiti Minimi

Base of proximal phalanx of little finger

Nerve Supply of Abductor Digiti Minimi

Deep branch of ulnar nerve

Action of Abductor Digiti Minimi

Abducts little finger

Origin of Flexor Digiti Minimi

Hook of hamate bone, flexor retinaculum

Insertion of Flexor Digiti Minimi

Base of proximal phalanx of 5th digit (little finger)

Nerve Supply of Flexor Digiti Minimi

Deep branch of ulnar nerve

Action of Flexor Digiti Minimi

Flexes proximal phalanx of 5th digit (little finger)

Origin of Opponens Digiti Minimi

Hook of hamate bone, flexor retinaculum

Insertion of Opponens Digiti Minimi

Medial border of 5th metacarpal bone

Nerve Supply of Opponens Digiti Minimi

Deep branch of ulnar nerve

Action of Opponens Digiti Minimi

Pulls 5th metacarpal forward (as in cupping the palm)

Origin of Palmaris brevis

Palmar aponeurosis, flexor retinaculum

Insertion of Palmaris brevis

Skin of medial palm

Nerve Supply of Palmaris brevis

Superficial branch of ulnar nerve

Action of Palmaris brevis

Tenses skin of palm for grip

Origin of Adductor policis

Oblique head; 2nd and 3rd metacarpal bones; transverse head; 3rd metacarpal bone

Insertion of Adductor policis

Base of proximal phalanx of thumb

Nerve Supply of Adductor policis

Deep branch of ulnar nerve

Action of Adductor policis

Adduction of thumb

Origin of Lumbricals

Tendons of flexor digitorum profundus

Insertion of Lumbricals

Extensor expansion of medial four fingers

Nerve Supply of Lumbricals

1st and 2nd (i.e. lateral two) median; 3rd and 4th deep branch of ulnar nerve

Action of Lumbricals

Flexes metacarpophalangeal joints and extend interphalangeal joints of fingers except thumb

Origin of Palmar Interossei (PAD)

Anterior surface of shafts of 2nd, 4th, and 5th metacarpals

Insertion of Palmar Interossei (PAD)

Proximal phalanges index, ring and little fingers and dorsal extensor expansion of each finger

Nerve Supply of Palmar Interossei (PAD)

Deep branch of ulnar nerve

Action of Palmar Interossei (PAD)

Palmar interossei adduct fingers toward center of 3rd finger

Origin of Dorsal Interossei

Continuous sides of shafts of metacarpal bones

Insertion of Dorsal Interossei

Proximal phalanges of index, middle and ring fingers and dorsal extensor expansion

Nerve Supply of Dorsal Interossei

Deep branch of ulnar nerve

Action of Dorsal Interossei

Dorsal interossei abduct fingers from center of third finger; both palmar and dorsal flex metacarpophalangeal joints and extend interphalangeal joint