The fingers are flexed at the interphalangeal joints and can't abduct or adduct.

指间关节屈曲，手指无法外展内收。

These muscles include the flexor digitorum profundus which flexes the fingers at the interphalangeal joints, and the extensor digitorum which hyperextend them at the metacarpal phalangeal joint.

前臂肌群包括指深屈肌（在指间关节处使手指屈曲）及指伸肌（在掌指关节处使手指过伸）。

Finally, both the ulnar and median nerves innervate the lumbricals, which are 4 muscles that extend the fingers at the interphalangeal joints, and keep them flexed at the metacarpal phalangeal joints.

最后，尺神经和正中神经都支配蚓状肌，这四条蚓状肌能使指间关节的手指伸直，同时掌指关节保持屈曲位。