Hand muscles

The hand serves as the origin and/or insertion for many muscles. The intrinsic muscles of the hand contain the origin and insertions within the carpal and metacarpal bones. Intrinsic hand muscles originate and insert from the bones, ligaments, and fascia of the hand. These muscles primarily produce fine motor movements and are divided into thenar, hypothenar, and adductor compartments

The extrinsic muscles of the hand originate outside the hand, commonly the forearm, and insert into hand structures.

A useful rule of thumb is that any muscle tendon that crosses a joint will act on that joint.

Reference

1. Raszewski JA et al. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Oct 24, 2023. Anatomy, Shoulder and Upper Limb, Hand Compartments