Pain in the lower back (7)
I believe the answer is:
lumbago
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pain in the lower back</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for lumbago that I've seen before include "Lower back ache" , "Back affliction" , "Rheumatism of lower back" , "Rheumatic pain in muscles of lower back" , "Rheumatic pain in the small of the back" .)