Heads towards, which helps to bring about (5,3)

'heads towards which helps' is the definition.
The definition and answer can be both to do with motion as well as being verbs in their -s form.
Perhaps you can see a link between them that I don't see?

'to bring about' is the wordplay.
I cannot quite understand how this works, but
'to' could be 'for' and 'for' is found in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is present in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?