Live within one's means, as a contortionist could (4,4,4)
I believe the answer is:
make ends meet
'live within one's means' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
(Other definitions for make ends meet that I've seen before include "Just about manage" , "Get by financially" , "Have enough money to buy essentials" , "Keep the wolf from the door?" , "Just have enough income" .)