Sticks up leg injured in run (7)
I believe the answer is:
smuggle
'run' is the definition.
(I've seen this before)
'sticks up leg injured' is the wordplay.
'sticks' becomes 'gums'.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'injured' indicates anagramming the letters.
'gums' back-to-front is 'smug'.
'leg' anagrammed gives 'gle'.
'smug'+'gle'='SMUGGLE'
'in' is the link.
(Other definitions for smuggle that I've seen before include "Run away from duty" , "Adherent of religion founded by Guru Nanak" , "Import without paying customs duties" , "boot-leg" , "Run contraband" .)