Freedom of movement on the stage (4)
I believe the answer is:
play
I believe this clue is a double definition.
'freedom of movement' is the first definition.
(as opposed to time spent in a classroom, say)
'the stage' is the second definition.
(thesaurus)
'on' is the link.
(Other definitions for play that I've seen before include "Portray in a drama" , "Perform music" , "Drama; engage in games" , "Recreation" , "Amuse oneself - drama" .)