be on the order of 1 25 inch once the positive impression is formed then one is ready to commence the fabrication of the support device of the present invention the mold illustrated in fig1 3 is used to form both the outer shell and the inner liner that together form the support structure fig4 6 illustrate the inner liner which is constructed of a more flexible material while the outer shell which is illustrated in fig7 9 is constructed of a more rigid material both of an appropriate plastic material the positive impression is positioned so that layers of a proflex thermal plastic material can be vacuum formed thereover a u215b inch thick sheet of thermoplastic material that is appropriately sized for the particular mold is heated and drape molded and then vacuum formed onto the positive impression making sure to clearly define the male portion of the locking mechanism or locking projection this would be formed by the part of the thermoplastic material that is draped over and vacuum formed against the projections 12 illustrated in fig1 3 this first disposed layer that is vacuum formed is for forming the flexible inner liner of the orthosis in this regard refer to fig4 6 showing the liner 20 with oppositely disposed projections 24 and a forward disposed parting line 22 in the molding and vacuum forming method the next step is to provide a thermal plastic rigid.