This disclosure describes a modular bridging structure and a system for using that structure. The bridging structure has a channel configured to receive a portion of an elongate rail, the channel being configured to receive the elongate rail substantially perpendicularly to a longitudinal axis of the modular bridging structure, and a rail fastener securing the received rail within the channel. Additionally, the modular bridging structure has a leg receiver configured to receive an elongate leg section such that the leg section is attached through a bottom side of the modular bridging structure. There is a leg fastener that secures the received leg section to the modular bridging structure such that the securing point of the fastener is adjustable along a plurality of points along each leg section.