Subject + 的 + 手臂
手臂 (shǒubì) refers to the arm, from shoulder to hand. It is a standard noun used in descriptions of the body, physical actions, or anatomical features of people and animals.
他的手臂上有一个小纹身。
Tā de shǒubì shàng yǒu yī gè xiǎo wénshēn.
He has a small tattoo on his arm.
搬完东西以后,我的手臂酸得抬不起来。
Bān wán dōngxi yǐhòu, wǒ de shǒubì suān de tái bù qǐlái.
After moving all the stuff, my arms were so sore I couldn't lift them.
医生仔细检查了她受伤的手臂。
Yīshēng zǐxì jiǎnchá le tā shòushāng de shǒubì.
The doctor carefully examined her injured arm.