The present invention relates to sliding support assemblies and particularly sliding supports having two (or more) elongate members, which slide one within the other. The invention addressed the problem of shearing between a pair of such sliding supports used on an article which may be subjected to forces from several directions and which may cause one or both of the supports to jam. The problem is addressed by the arrangement of the elongate members on a sliding support assembly. The invention also provides a locking mechanism for locking an article being supported by the sliding support assembly in place relative to a base of the assembly.