Those paying the cost for central pains in back at the ends of lumbar regions (10)
I believe the answer is:
financiers
'those paying the cost' is the definition.
I can't tell whether this definition defines the answer.
'central pains in back at the ends of lumbar regions' is the wordplay.
'central' indicates the central letters.
'in' indicates putting letters inside.
'back' becomes 'finance' (I've seen this before**).
'at the ends of' says to take the final letters (I've seen 'at the end' mean this).
The central letter of 'pains' is 'i'.
The last letters of 'lumbar regions' are 'rs'.
'i' inserted into 'finance' is 'financie'.
'financie'+'rs'='FINANCIERS'
'for' is the link.
Can you help me to learn more?
(Another definition for financiers that I've seen is " workers in the City?".)