While in some gliders I've flown the trim actually mechanically acts on the stick, through a spring, in most aircraft the trim controls, electrical or mechanical, act on trim tabs on the control surfaces.
In a Baron 58, a C90, etc... on the ground, with no significant airflow the controls will not move ( the yoke and the rudder will stay put... )
With dynamic pressure build up, the airflow over the control surfaces and their trim tabs will then force them up / down or left right depending on the control surface and trim input by the pilot, and then we can see the controls moving accordingly in the aircraft.
Presently when we make aileron, elevator or rudder trim inputs in Aerofly FS 2 that have this trim options, we can see the controls moving even on ground, with the aircraft stopped.