How can admitting steam at the middle of a large reaction turbine reduce axial thrust?

In a reaction turbine, the pressure drop across the rotor blades creates a net force in the axial direction, which pushes the rotor toward the ends of the casing and necessitates the use of a thrust bearing to manage the load.1

To reduce this axial thrust in large turbines, engineers admit the steam flow into the middle of the turbine. By doing so, the steam expands in both axial directions simultaneously. This "double-flow" arrangement causes the axial forces generated by the steam expansion on one side of the turbine to be balanced by the opposing forces on the other side, significantly minimizing the net axial load on the rotor.1