Every so often my ankles turn (4)
I believe the answer is:
make
'turn' is the definition.
(thesaurus)
'every so often my ankles' is the wordplay.
'every so often' means one should take alternating letters.
'my'+'ankles'='myankles'
The alternate letters of 'myankles' are 'MAKE'.
(Other definitions for make that I've seen before include "Manufacture, form" , "Appoint" , "Build" , "Create; a brand" , "Fabricate" .)