Intrinsic Muscles of the Hand Flashcards
pneumonic for the interossei for the hand
start from lateral side of index finger: Dogs Poop Dogs Don't Poop Dogs Poop
DAB –> Dorsal ABducts
PAD–> Palmar ADducts
D stands for Dorsal Interossei Muscles
P stands for Palmar Interossei Muscles
What are the Thenar Muscles?
1) Oppnens Pollicis
2) Abductor Pollicis Brevis
3) Flexor Pollicis Brevis : Superficial Head and Deep Head
4) Adductor Pollicis: Oblique Head and Transverse Head
Origin of Opponens Pollicis
1) Flexor Retinaculum
2) Tubercles of Scaphoid and Trapezium
Insertion for Oppenens Pollicis
Lateral Side of 1st Metacarpal
Innervation of Opponens Pollicis
Recurrent Branch of Medial Nerve (C8, T1)
Action of Opponens Pollicis
To oppose the thumb, it draws the 1st metacarpal medially to center of the palm and rotates it medially
Origin of Abductor Pollicis Brevis
1) Flexor Retinaculum
2) Tubercles of the Scaphoid and Trapezium
Insertion of Abductor Pollicis Brevis
Lateral Side of Base of Proximal Phalanx of Thumb
Innervation of Abductor Pollicis Brevis
Recurrent Branch of Median Nerve (C8, T1)
Action of Abductor Pollicis Brevis
Abducts the thumb; and helps oppose it
Origin of Flexor Pollicis Brevis (Superficial Head and Deep Head)
1) Flexor Retinaculum
2) Tubercles of Scaphoid and Trapezium
Insertion of Flexor Pollicis Brevis
Lateral Side of Base of Proximal Phalanx of Thumb
Innervation of Flexor Pollicis Brevis
Superficial Head: Recurrent Branch of Median Nerve (C8,T1)
Deep Head: Deep Branch of Ulnar Nerve (C8,T1)
Action of Flexor Pollicis Brevis
Flexes the Thumb
Origin of Adductor Pollicis (Oblique Head and Transverse Head)
1) Oblique Head: a) Bases of 2nd and 3rd Metacarpals
b) Capitate
c) Adjacent Metacarpals
2) Transverse Head: Anterior Surface of Shaft of Third Metacarpal
Insertion of Adductor Pollicis
Medial Side of Base of Proximal Phalanx of Thumb
Innervation of Adductor Pollicis
Deep Branch of Ulnar Nerve (C8,T1)
Action of Adductor Pollicis
Adducts thumb towards lateral border of palm
What are the Hypothenar Muscles?
1) Abductor Digiti Minimi
2) Flexor Digiti Minimi Brevis
3) Opponens Digiti Minimi
Origin of Abductor Digiti Minimi
Pisiform
Insertion of Abductor Digiti Minimi
Medial Side of Base of Proximal Phalanx of 5th Finger
Innervation of Abductor Digiti Minimi
Deep Branch of Ulnar Nerve (C8,T1)
Action of Abductor Digit Minimi
Abducts the 5th finger; assists of its proximal phalanx
Origin of Flexor Digiti Minimi Brevis
1) Hook of Hamate
2) Flexor Retinaculum
Insertion of Flexor Digiti Minimi Brevis
Medial Side of Base of Proximal Phalanx of 5th Finger
Innervation of Flexor Digiti Minimi Brevis
Deep Branch of Ulnar Neve (C8, T1)
Action of Flexor Digiti Minimi Brevis
Flexes the Proximal Phalanx of 5th Finger
Origin of Opponens Digiti Minimi
1) Hook of Hamate
2) Flexor Retinaculum
Insertion of Opponens Digiti Minimi
Medial Border of 5th Metacarpal
Innervation of Opponens Digiti Minimi
Deep Branch of Ulnar Nerve (C8,T1)
Action of Opponens Digiti Minimi
Draws 5th Metacarpal anterior and rotates it, bringing 5th finger into opposition with the thumb
What are the short muscles of the hand?
Lumbricals (1&2, 3&4) Dorsal Interossei (1-4) Palmar Interossei (1-3)
Origin of Lumbricals 1&2
Lateral two tendons of Flexor Digitorum Profundus (as unipennate muscles)
Insertion of Lumbricals 1&2
Lateral Side of Extensor Expansions 2nd-5th fingers
Innervation of Lumbricals 1&2
Median Nerve (C8, T1)
Action of Lumbricals 1&2
Flex Metacarpophalangeal Joints; extend interphalangeal joints of 2nd-5th fingers
Origin of Lumbricals 3&4
Medial Three Tendons of Flexor Digitorum Profundus (as bipennate muscles)
Insertion of Lumbricals 3&4
Lateral Sides of Extensor Expansions of 2nd-5th Fingers
Innervation of Lumbrcials 3&4
Median Nerve (C8 and T1)
Action of Lumbricals 3&4
Flex Metacarpophalangeal Joints; extend interphalangeal joints of 2nd-5th fingers
Origin of Dorsal Interossei 1-4
Adjacent sides of two metacarpals (as bi-pennate muscles)
Insertion of Dorsal Interossei 1-4
Bases of Proximal phalanges; extensor expansions of 2nd-4th fingers
Innervation of Dorsal Interossei 1-4
Deep Branch of Ulnar Nerve (C8-T1)
Action of Dorsal Interossei 1-4
Abduct 2nd-4th Fingers from Axial Line; act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
Origin of Palmar Interossei 1-3
Palmar Surface of 2nd, 4th, and 5th metacarpals (as unipennate muscles)
Insertion of Palmar Interossei 1-3
Bases of Proximal Phalanges; Extensor Expansions of 2nd, 4th and 5th fingers
Innervation of Palmar Interossei 1-3
Deep Branch of Ulnar Nerve (C8,T1)
Action of Palmar Interossei 1-3
Adduct 2nd, 4th, and 5th Fingers towards axial lines; assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints