"origin: contiguous (adjacent) sides of the five metacarpal bones"
"insertion: extensor hood of their related digit and the base of the proximal phalanx"
"innervation: deep branch of the ulnar nerve (C8, T1)"
"action"
"Palmar = ADduction"
"Palmar = ADduction"
"Dorsal = ABduction"
"Dorsal = ABduction"
"The mnemonic “PAD” and “DAB” can be used to help remember the different functions of the two muscle groups."
"Palmar = ADduction"
"Dorsal = ABduction"
"Palmar = ADduction"
"Dorsal = ABduction"
Expected headings
"Blood supply"
"Clinical pearls"
"Clinical testing"
"The interossei muscles form part of the intrinsic muscles of the hand, and as a group consisting of four palmar (1st is often rudimentary) and four dorsal muscles. Collectively, the interossei contribute to abduction and adduction of the fingers and also contribute to flexion of the metacarpophalangeal joints (MCPJ) and extension of the interphalangeal joints (IPJ) through their insertion onto the extensor hood. The reference axis through which abduction and adduction occur is the long axis of the 3rd phalanx (middle finger)."
"primary: abduction of 2nd, 3rd, and 4th fingers at the MCPJ joints; the 3rd finger can abduct both medially and laterally"