its a term used to put your arm around someone. you start with counting ur far shoulder away from them as one, two which is the closest one to them, 3 their first and 4th the farthest one on the other side and keep ur arm around them
“have you ever counted shoulders before?”
“dude, i just used the counting shoulders trick on katie and it worked!”
Means the opposite of "broad shouldered" (to act strong and confident and carry alot of burden/responsility in your stride). People (usually a manager) acquire this title by dodging work and/or making decisions and generally pass the buck onto a subordinate. This is done to avoid blame or to avoid doing a task that may be boring.
Officeworker 1: Dave the manager has just given me a pile of accounts to work on thats going to be externally audited!!
Officeworker 2: But he's more qualified than you to do it! Jeez that guy has got such slopey shoulders!