What is the main action of the palmar interossei?

The primary action of the palmar interossei muscles is indeed the adduction of the 2nd, 4th, and 5th fingers at the metacarpophalangeal (MP) joint. These muscles are located on the palmar side of the hand and facilitate bringing the fingers toward the midline of the hand.

In the context of hand anatomy, the interossei muscles are divided into two groups: the palmar interossei, which are responsible for adduction, and the dorsal interossei, which are responsible for abduction. The palmar interossei specifically target the fingers that move inward towards the third digit, which is considered the midline for finger movements.

This action is essential for functions such as gripping, pinching, and any activity requiring fine motor control involving finger movements.