肱肌在肱二头肌包裹之下，仙漏在大臂外侧上部，肱二头肌和肱三头肌之间的叫肱肌外侧头，可在体表起结构作用；显露在大臂内侧下部，肱二头肌和肱三头肌之间的叫肱肌内侧头，体表并不起多大的结构作用。

The brachialis (brachialis anticus) is a muscle in the upper arm that flexes the elbow joint. It lies deeper than the biceps brachii, and is a synergist that assists the biceps brachii in flexing at the elbow. It makes up part of the floor of the region known as the cubital fossa.