contact of the curvature 412 to the member 406 prevents further extension one skilled in the art will recognize that symmetrical non linear members having curvatures on both sides of the central portion 410 may also be used fig6 shows a diagram 600 of the distribution of force relative to the truss like configuration 604 of the embodiment 400 when partially extended the load 602 supplies a component of force that is perpendicular to both the lateral dimension 424 and longitudinal dimension 422 of fig4 the load 602 is distributed throughout the truss like configuration 604 as forces are generated through the pins 414 and members 406 holding the structure 400 together again as the height h of the truss like configuration 604 increases which results from some retraction and a corresponding decrease in the length l in the longitudinal dimension 422 the load carrying capacity increases as the length l of the truss like configuration 604 increases which results from some extension and a corresponding decrease in the height h the load carrying capacity decreases because the maximum extension occurs prior to the structure 400 becoming flat the truss like configuration 604 is preserved and the resulting structural advantage is maintained regardless of whether the curvature 412 is present on the side where the load is applied or on the opposite side when the load is applied to the same side of.