The lumbrical muscles lead to the flexion on the metacarpophalangeal joints and also to the extension with the interphalangeal joints. They originate in the flexor digitorum profundus tendons with the palm and insert over the radial aspect of the extensor tendons on the digits. The ECRB inserts at the base https://marioqyfk18518.wikilinksnews.com/5237117/crafting_excellence_the_rivet_manual_hand_press_in_artisanal_work