In pain, somehow did provide the extra writing (7)
I believe the answer is:
padding
'the extra writing' is the definition.
The answer and definition can be both to do with communicating as well as being present participle verbs.
Perhaps there's an association between them I don't understand?
'in pain somehow did' is the wordplay.
'in' is an insertion indicator.
'pain' becomes 'pang' (pang is a kind of pain).
'somehow' indicates anagramming the letters.
'did' is an anagram of 'ddi'.
'pang' going around 'ddi' is 'PADDING'.
'provide' acts as a link.
Can you help me to learn more?
(Another definition for padding that I've seen is " Soft stuffing".)