ORIGIN: anterior retinaculum and palmer aponeurosis.INSERTION:skin ulnar border of hand.NERVE:superficial ulnar. ACTION:pulls on skin over thenar eminence, deepening cup of the palm and improving grip.
Opponens Pollicus
ORIGIN: flexor retinaculum, trapezium. INSERTION:radial border 1st metacarpal. NERVE:median thenar branch.ACTION:draws 1st metacarpal laterally to opose the thumb toward center of palm and rotates it medially.
Palmar Interosseous
ORIGIN: sides of metacarpals.INSERTION:extension expansion hood of digits 2,4,5. NERVE:deep branch ulnar.ACTION:adduction of fingers.
Dorsal Interosseous Muscles
ORIGIN:sides of metacarpals.INSERTION:extension expansion hood of digits 2-4.NERVE:deep branch ulnar. ACTION:abducts fingers.
Flexor Pollicus Brevis
ORIGIN:flexor retinaculum trapezium. INSERTION: thumb. NERVE: median thenar branch. ACTION:Flexes the thumb at the first metacarpophalangeal joint.
Adductor Policus
ORIGIN:capitate and base of adjacent metacarpals. INSERTION:proximal phalanks of thumb.NERVE:deep branch of ulnar.ACTION:draws thumb toward palm and rotates it medialy.
Lumbricals
ORIGIN:tendons of flexor digitorum profundus.INSERTION:extension expansion hood of medial 4 digits.NERVE:deep branch ulnar(medial 2 L's) median (lateral 2 L's).ACTION:flexes fingers and extends interphalgeal joints.
Oponens Digiti Minimi
ORIGIN:flexor retinaculum,hamate.INSERTION:ulnar medial border(5th metacarpal).ACTION:draws 5th metacarpal anteriorly and rotates it,bringing little finger into oposition with the thumb.
