Interosseous Compartment Muscles

Dorsal Interossei Purposeful Activity

Typing

Dorsal Interossei Action

• 2nd–4th fingers abduction from axial line

• Act with lumbricals in flexing

metacarpophalangeal joints and extending

interphalangeal joints

Dorsal Interossei Origin

Adjacent sides of two metacarpals (as bipennate

muscles)

Dorsal Interossei Insertion

• Bases of proximal phalanges

• Extensor expansions (more proximal than

lumbricals) of 2nd –4th fingers

Dorsal Interossei Innervation

Deep branch of ulnar nerve (C8, T1)

Dorsal Interossei Blood Supply

Palmar metacarpal arteries

DABs

dorsal interossei ABDuct

dorsal interossei

Index finger has 1, middle finger has 2, ring finger has 1 (4 total)

Palmar Interossei Purposeful Activity

Playing the piano

Palmar Interossei Action

• 2nd, 4th, and 5th fingers adduction toward axial

line

• Act with lumbricals in flexing

metacarpophalangeal joints and extending

interphalangeal joints

Palmar Interossei Origin

Palmar surfaces of 2nd, 4th, and 5th metacarpals (as

unipennate muscles)

Palmar Interossei Insertion

• Bases of proximal phalanges

• Extensor expansions (more proximal than

lumbricals) of 2nd, 4th, and 5th fingers

Palmar Interossei Innervation

Deep branch of ulnar nerve (C8, T1)

Palmar Interossei Blood Supply

Palmar metacarpal arteries

PADs

palmar interossei ADDuct

Palmar Interossei

Index finger 1, middle finger has 0, ring finger has 1 and

little finger has 1 (3 total)