They were standing shoulder to shoulder.

他们肩并着肩站着。

《新英汉大辞典》

They're standing shoulder to shoulder.

它们肩并肩地站着。

youdao

Actually, it looked like everybody was really calm, like on the subway platform when it's really, really crowded and everyone's standing shoulder to shoulder.

他说“实际上人们看上去都十分的冷静，就像在一个很拥挤的地铁站台上那样，人们肩并着肩站着。”

youdao

On Thursday afternoon, police vehicles lined Times Square in a show of force, with officers standing shoulder to shoulder.

BBC: Boston suspects 'targeted New York's Times Square'

And we have so many signs of the intertwined world--the pictures being transmitted from Europe before the bombing or the leaders of the great industrial nations standing shoulder to shoulder.

NPR: New York, Los Angeles Step Up Security

"It's a welcome relief for Pete Domenici and I to be standing shoulder to shoulder, not nose to nose, " Lautenberg told reporters, in a reference to the two-year-old budget fight that has dominated national politics.

CNN: House Budget Panel Approves Budget Agreement