- See: Intrinsic Muscles of the Hand;
- Origin: each from the 2 metacarpal bones between which it inserts;
- superficial belly:
- inserts onto the lateral tubercle at the base of the proximal phalanx (proximal phalanges of 2nd, 3rd, and 4th digits)
to function as an abductor;
- deep belly: inserts onto the lateral tendon to help form the lateral band of the radial three fingers;
- Action: the 1st abducts the index finger, the 2nd radially flexes the
- middle finger, 3rd flexes middle finger & 4th abducts ring finger;
- all assists in flexing proximal phalanges of the index, middle and ring fingers at metacarpophalangeal joints;
- Nerve supply: palmar branch of the Ulnar nerve, C8 , T1
- Synergists: lumbrical, Palmar Interossei, Flexor Digitorum Profundus, Flexor Digitorum Superficialis
- First Dorsal Interosseous:
- largest of the interossei;
- origin: inner borders of first and second metacarpals;
- passes dorsal to adductor pollicis;
- insertion: extensor expansion mechanism on dorsum of finger;
- 1st, 2nd, and 4th, dorsal interossei - 2 muscle bellies:
- one of which inserts on the base ofthe proximal phalanx;
- one of which inserts on the dorsal aponeurosis;
- 3rd dorsal interosseous and all 3 volar interossei insert on to only dorsal aponeurosis;
Opponensplasty in intrinsic-muscle paralysis of the thumb in leprosy.
Patterns of movement of totally intrinsic-minus fingers based on a study of one hundred and forty-one fingers.
Movement patterns of interosseus-minus fingers.
Abductor pollicis longus transfer for replacement of first dorsal interosseous.
Architectural design of the human intrinsic hand muscles.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Friday, December 2, 2011 3:10 pm