It's lowering, going on those benders of yours! (5)
I believe the answer is:
knees
'lowering going on those benders of yours' is the definition.
I can't judge whether this definition defines the answer.
'it's' is the wordplay.
I cannot quite understand how this works, but
'it's' could be 'es' ('e' can mean 'electronic' which is similar to 'IT') and 'es' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for knees that I've seen before include "Hinge joints" , "Legs' joints" , "Hinged joints" , "Leg joints" , "Lap" .)