Joint provides soothing effect to some extent (5)
I believe the answer is:
hinge
'joint' is the definition.
(I've seen this before)
'provides soothing effect to some extent' is the wordplay.
'to some extent' indicates a hidden word.
'HINGE' is hidden within 'provides soothing effect'.
(Other definitions for hinge that I've seen before include "Door support" , "Key principle" , "Moveable joint" , "Joint on which something swings" , "Flexible joint" .)