Micky, the 146/RJ servo tabs provide the aerodynamic force to move the elevator, the tabs are connected directly to the control column. There are no control locks and as B1/B2 indicates the column and tabs are ‘restrained’ in the centre of the pitch range so that on the ground the tabs do not get damaged by the ‘free’ elevators. The elevators themselves have ground gust dampers located within the tail-plane, these differ from the recently added in-flight dampers which are in the tail-plane / fin top fairing.
On the ground the elevator usually positions nose down (trailing edge up) due to the balance weights in the leading edge. However the elevators can move independently of the tab and themselves (left / right) even in low wind speeds, the gust dampers only prevent rapid movement. Although the servo tab is fixed with respect to the column, the elevator is free to move with respect to the tab. Thus with the column restrained, only the wind can move the elevator and not the tab, but each interacts with the other in strong winds.
For the aerodynamically astute there is also a spring (torsion bar) in the servo tab control, but that’s far too difficult to explain; thus for you and I, the 146/RJ only has servo tabs.