Painful inflammation in shoulders; it is rubbing when turning round (8)
I believe the answer is:
bursitis
'painful inflammation' is the definition.
'in shoulders it is rubbing when turning round' is the wordplay.
'in' indicates the answer is hidden within the clue.
'turning round' says the letters should be written in reverse.
'sitisrub' is hidden within 'shoulders it is rubbing when'.
'sitisrub' in reverse letter order is 'BURSITIS'.
(Other definitions for bursitis that I've seen before include "Condition such as housemaid's knee" , "Inflammation of a shoulder joint" .)