Re: Ferris Bueller!
'carrying its shoulder.
BTW, should there be an apostrophe in the "it's" above?'
Let's work that out. "It's" is short for "it is". So does "carrying it is shoulder" make sense? No it doesn't. So there shouldn't be an apostrophe.
Alternative version: "its" is an impersonal pronoun equivalent to "his". Do you write "hi's"? No you don't so when you need a possessive pronoun you use "its".
HTH