Abstract: Support panels and modular assemblies thereof, the panels adapted for supporting removable load bearing members such as brackets. The panels comprise hollow bodies defining channels for receiving and supporting load bearing members. The hollow bodies further include support ribs extending between front and back walls of the panels to transfer forces exerted on flange portions of the channels by the load bearing members to the back walls and/or to other structural portions of the panels, the support ribs being offset from the perpendicular relative to the front and back walls of the panels. Pluralities of the panels may be joined by mating edges, which can define further channels for receiving and supporting load-bearing members, to form modular wall assemblies without the need for mounting overtop existing surfaces as said panels can be mounted directly on structural supports (e.g. stud walls).