knuckles

He barked his knuckles on the doorjamb.

他碰在门侧柱上擦破了指关节处皮。

his knuckles were white as he gripped the steering wheel.

他紧握方向盘，握得手指关节发白。

He got a rap over the knuckles for spending too much money on his business lunches.

因为在商务午餐上花钱太多，他挨了一顿批评。

The most common type of joint in the human body is the diarthrodial joint -- knuckles and shoulders are examples -- in which two bones come together in a capsule.

人体中最关节是运动关节，如指关节和肩关节等，关节处一个囊状物把两根骨头结合在一起。