Stop going backwards and forwards (4,2)
I believe the answer is:
pull up
'stop' is the definition.
(to pull someone up is to stop them doing something)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pull up that I've seen before include "Exercise" , "Stop or cause to stop" , "park" , "Halt" , "Take to task" .)