Apparatus for actuating one or more latching arrangements of one or more respective rocker arms (3, 3a, 3b) of a valve train assembly of an internal combustion engine, each rocker arm (3, 3a, 3b) comprising a first body, a second body for pivotal motion with respect to the first body, and said latching arrangement, the latching arrangement being for latching and unlatching the first body and the second body, the apparatus comprising: a shaft (25, 27a) rotatable by an actuation source; one or more selector cams (29, 31, 32) rotatable by the shaft (25, 27a), each selector cam (29, 31, 32) for actuating the latching arrangement of a respective rocker arm (3, 3a, 3b) so as to latch and/or unlatch the first body and the second body; characterized in that, said shaft (25, 27a) is rotatable by said actuation source, from a rest orientation, in a first direction, and rotatable by said actuation source, from the rest orientation, in a second direction opposite to the first direction; and return apparatus (300, 400) for returning the shaft (25, 27a) to the rest orientation, the return apparatus (300, 400) comprising: one or more radial protrusions (302, 402a, 402b) protruding radially out from the shaft (25, 27a); a reaction body (306, 406); and a biasing means (304, 404) arranged for contacting the reaction body (306, 406) and for contacting the one or more radial protrusions (302, 402a, 402b); wherein the return apparatus (300, 400) is arranged such that, in use, when the shaft (25, 27a) is in the rest orientation the biasing means (304, 404) applies substantially no rotational force to the shaft (25, 27a), when the shaft (25, 27a) is rotated from the rest orientation in the first direction the biasing means (304, 404) contacts the reaction body (306, 406) and one or more of the radial protrusions (302, 402a, 402b) so as to bias the shaft (25, 27a) rotationally in the second direction to towards the rest orientation, and when the shaft (25, 27a) is rotated from the rest orientation in the second direction the biasing means (304, 404) contacts the reaction body (306, 406) and one or more of the radial protrusions (302, 402a, 402b) so as to bias the shaft (25, 27a) rotationally in the first direction to towards the rest orientation. a shaft (25, 27a) rotatable by an actuation source; one or more selector cams (29, 31, 32) rotatable by the shaft (25, 27a), each selector cam (29, 31, 32) for actuating the latching arrangement of a respective rocker arm (3, 3a, 3b) so as to latch and/or unlatch the first body and the second body; characterized in that, said shaft (25, 27a) is rotatable by said actuation source, from a rest orientation, in a first direction, and rotatable by said actuation source, from the rest orientation, in a second direction opposite to the first direction; and return apparatus (300, 400) for returning the shaft (25, 27a) to the rest orientation, the return apparatus (300, 400) comprising: one or more radial protrusions (302, 402a, 402b) protruding radially out from the shaft (25, 27a); a reaction body (306, 406); and a biasing means (304, 404) arranged for contacting the reaction body (306, 406) and for contacting the one or more radial protrusions (302, 402a, 402b); wherein the return apparatus (300, 400) is arranged such that, in use, when the shaft (25, 27a) is in the rest orientation the biasing means (304, 404) applies substantially no rotational force to the shaft (25, 27a), when the shaft (25, 27a) is rotated from the rest orientation in the first direction the biasing means (304, 404) contacts the reaction body (306, 406) and one or more of the radial protrusions (302, 402a, 402b) so as to bias the shaft (25, 27a) rotationally in the second direction to towards the rest orientation, and when the shaft (25, 27a) is rotated from the rest orientation in the second direction the biasing means (304, 404) contacts the reaction body (306, 406) and one or more of the radial protrusions (302, 402a, 402b) so as to bias the shaft (25, 27a) rotationally in the first direction to towards the rest orientation. one or more radial protrusions (302, 402a, 402b) protruding radially out from the shaft (25, 27a); a reaction body (306, 406); and a biasing means (304, 404) arranged for contacting the reaction body (306, 406) and for contacting the one or more radial protrusions (302, 402a, 402b); wherein the return apparatus (300, 400) is arranged such that, in use, when the shaft (25, 27a) is in the rest orientation the biasing means (304, 404) applies substantially no rotational force to the shaft (25, 27a), when the shaft (25, 27a) is rotated from the rest orientation in the first direction the biasing means (304, 404) contacts the reaction body (306, 406) and one or more of the radial protrusions (302, 402a, 402b) so as to bias the shaft (25, 27a) rotationally in the second direction to towards the rest orientation, and when the shaft (25, 27a) is rotated from the rest orientation in the second direction the biasing means (304, 404) contacts the reaction body (306, 406) and one or more of the radial protrusions (302, 402a, 402b) so as to bias the shaft (25, 27a) rotationally in the first direction to towards the rest orientation.