彼らは腕をくんで歩いてきた。

they (usually male); them

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

arm; skill; efforts; ability

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to draw (water); to fetch (water); to ladle; to dip; to scoop; to pump; to have a drink together; to consider; to sympathize with; to sympathise with

to walk