Wind round the base of the log, causing pain (6)
I believe the answer is:
twinge
'pain' is the definition.
(twinge is a kind of pain)
'wind round the base of the log' is the wordplay.
'wind' becomes 'twin' (I can't explain this - if you can you should give a lot more credence to this answer).
'round' says the letters should be written in reverse.
'the base of' suggests the final letters.
The last letters of 'the log' are 'eg'.
'eg' back-to-front is 'ge'.
'twin'+'ge'='TWINGE'
'causing' is the link.
Can you help me to learn more?
(Other definitions for twinge that I've seen before include "little pain" , "Sudden sharp feeling" , "Sharp localised pain" , "A slight stab of pain" , "Momentary pain" .)