Assume performance banning women's ruled out (8)
I believe the answer is:
'assume performance' is the definition.
'shoulder' can be an answer for 'assume' (shoulder can mean to assume or take on). I am not certain of the 'performance' bit.
'banning women's ruled out' is the wordplay.
'banning women' becomes 'sho' (I can't explain this - if you can you should give a lot more credence to this answer).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'ruled' is an anagram of 'ulder'.
(Other definitions for shoulder that I've seen before include "Body part of a strange old usher" , "Bear (burden); joint" , "Undertake (burden)" , "On the side of the road, it might be hard" , "Bear < to push" .)