Check pins used for shock treatment (7)
I believe the answer is:
inspect
'check' is the definition.
(I've seen this before)
'pins used for shock treatment' is the wordplay.
'used' is an anagram indicator.
'for' is a charade indicator (letters next to each other).
'shock treatment' becomes 'ECT' (ECT is an example).
'pins' is an anagram of 'insp'.
'insp'+'ect'='INSPECT'
(Other definitions for inspect that I've seen before include "Check" , "Look critically at" , "Scrutinize, audit" , "Ecamine closely" , "Study" .)