Hands

IP joints

between proximal and distal phalanxes

MCP joint

between head of 1st metacarpal with proximal phalanx of thumb

TMC

between the 1st metacarpal articulating with the trapezium = saddle joint

radial abduction

moving thumb in frontal plane towards radius

palmar abduction

bringing thumb away from palm in sagittal plane

RC joint

= radiocarpal joint → the radius articulates with the scaphoid and lunate → condyloid, synovial joint that allows flexion, extension, abduction, adduction, and circumduction

DRU joint

= distal radioulnar joint → pivot synovial joint that allows supination and pronation

IC joint

= intercarpal joint = betwen carpal bones → plane synovial joint, allowing for gliding and sliding

MC joint

= midcarpal = between proximal and distal carpal rows → plane synovial joint allowing for gliding, sliding, flexion, abduction

CMC joint

= between carpals and metacarpals → plane synovial providing gliding and sliding, except thumb which is a saddle giving more mobility for opposition and other movements

intrinsic hand muscles

• flexor digiti minimi

• abductor digiti minimi

• opponens digiti minimi

• flexor pollicis brevis

• abductor pollicis brevis

• opponens pollicis

• adductor pollicis

• palmaris brevis

• lumbricals (4)

• interosseois (3 palmar, 4 dorsal)

flexor digiti minimi N + A

ulnar nerve

flexes the little finger

abductor digiti minimi N + A

ulnar nerve

abducts the little finger

opponens digiti minimi N + A

ulnar nerve

opposition → moves little finger to any of the other fingers

deep to flexor digiti minimi and abductor digiti minimi

flexor pollicis brevis N + A

median nerve

flexes the thumb

abductor pollicis brevis N + A

median nerve

palmar abduction of the thumb

opponens pollicis N + A

median nerve

opposition → thumb moving to any of the other fingers

adductor pollicis origin

oblique head: bases of 2nd and 3rd metacarpals, capitate

transverse head: anterior surface of shaft of 3rd metacarpal

adductor pollicis insertion

medial side of the base of proximal phalanx of thumb

adductor pollicis innervation

ulnar nerve

adductor pollicis brevis action

adducts the thumb , key pinching lu

lumbricals origin

tendon of FDP - flexor digitorum profundus

lumbricals insertion

(digits 2-5)

extensor apparatus of EDC (extensor digitorum communicus) on the radius side of the fingers

lumbricals innervation

digits 2-3 = median

digits 4-5 - ulnar

lumbricals action

MCP flexion, IP extension → makes a table with your hand

palmar interosseous A + N

= PAD → palmer ADDuct digits

ulnar nerve

lies between metacarpals

dorsal interosseous N + A

= DAB → dorsal ABduct the digits

ulnar nerve

lies between metacarpals