What does 일거수일투족 mean?

ANSWER: each raised hand, each step taken

In a pdf file HERE, which lists 142 Korean metaphors, the following example sentence was given for one of them:

그는 매의 눈으로 부하들의 일거수일투족을 모두 감시하고 있었다.

He was watching his subordinates' every move with hawk eyes.

The sentence was meant to be an example of the usage of 매의 눈, which means hawk eyes, but I was more interested in the expression 일거수일투족 (一擧手一投足), which was translated as every move. The literal meaning of the expression, however, is each (一) raised (擧) hand (手), each (一) taken (投) step (足). An equivalent expression is 일거일동 (一擧一動), which translates as every (一) action (擧), every (一) movement (動). The word 거동 (擧動) is equivalent to 행동 (行動), which means action, movements, conduct, or behavior.