The invention relates to a support structure comprising a support assembly that is supported by legs. The support assembly can be pivoted around a pivoting axis (4) relative to the legs from a position of use to a rest position and can be blocked from pivoting in the position of use by a fixing member. In an advantageous improvement of such a structure, the captivation member is configured as a latch (5) that engages, in the position of use, with a wedge-type blocking surface (8) by means of a spring force, thereby forcing it against a blocking shoulder (9,9′).