It's gonna be a hairline metacarpal fracture.

是掌骨轻微骨裂。

It's a minor break in the fifth metacarpal.

第五掌骨有一点小骨折。

Clean fracture of the metacarpal bone.

掌骨干净骨折。

But the underlying structures of the humerus, radius and ulna, and metacarpals, are shared.

但是肱骨、桡骨和骨以及掌骨的基础结构是共享的。

Broken knuckles, also known as metacarpal fractures, are fairly common, leading to the term “boxer’s fracture” or “brawler’s fracture”.

指关节骨折， 也称为掌骨骨折， 相当常见，导致术语“拳击手骨折”或“斗殴者骨折” 。

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.

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，神和正中神都支配蚓状肌，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。