Don't look after injured leg caught in trap (7)
I believe the answer is:
neglect
'don't look after' is the definition.
(to neglect is to fail to look after)
I cannot understand how the remainder of the clue works.
(Other definitions for neglect that I've seen before include "Lack of due care and attention" , "Failure to observe" , "Fail to act or take care" , "Fail to notice or care for" , "forget" .)