A platform assembly includes a first platform module having an elongated front face, a second platform module having an elongated front face, and a locking member for locking the front faces of the first and second platform modules to each other. The locking member is movably mounted on the first platform module in a longitudinal direction of the front face thereof, and at least one of the locking member and the second platform includes a locking protrusion, and the other of the locking member and the second platform includes a locking slot, wherein the locking protrusion is received by the locking slot and protrudes from the front face of the first platform module. An edge of the locking protrusion is behind an edge of the locking slot when the locking member is moved in said longitudinal direction of the front face, thereby locking the platform modules to each other.