Flexion of metacarpophalangeal joint and extension of interphalangeal joints is major action of
It is the action of lumbricals.The dorsal interossei abduct the fingers. the palmar interossei adduct the fingers.The FDS flexes middle phalanx at PIP joints. ref :textbook of anatomy upper limb and thorax ,vishram singh ,2nd edition ,page no.144
Palmar interossei
Dorsal interossei
Lumbricals
FDS
Upper limb