It's painful below (10,5)

'it's painful' is the definition.
(type of painful injury)

'below' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'below' is 'elbow' which is within the answer.
The remaining letters 'dislocated' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).