A positioning and locking system for positioning and maintaining an output member includes a transmission assembly configured to transmit rotational motion, a locking device having a locking element movable between an unlocked position and a locked position, and an actuator operatively coupled to the locking element. In operation, the transmission assembly is permitted to rotate in the unlocked position to allow positioning of the output member. When the locking element is moved to the locked position, the locking element engages a portion of the transmission assembly to prevent rotation thereof, thereby maintaining the output member in a fixed position. The system enables controlled positioning and secure mechanical locking without requiring continuous power input.