Foot orthotic

Abstract

A foot orthotic is configured to be removably installed in a shoe and includes an upper layer, a middle layer and a lower layer adhered together. The upper layer is formed of a viscoelastic material. The middle layer is formed of a thermoplastic material. The lower layer is formed of a thermoset material.

1 . A foot orthotic comprising: 
 an upper layer formed of a viscoelastic material;    a middle layer formed of a thermoplastic material; and    a lower layer formed of a thermoset material;    the layers being adhered together, and the orthotic being configured to be removably installed in a shoe.    
     
     
         2 . The orthotic of  claim 1  wherein the thermoplastic material has a softening temperature of about 55-80° C., whereby the orthotic can be pressed by a foot while the middle layer is in a heat-softened state during a custom-molding process but will not heat-soften during normal use.  
     
     
         3 . The orthotic of  claim 1  further comprising a thermal tag that changes color at a predetermined temperature, adhered to a surface of the orthotic.  
     
     
         4 . The orthotic of  claim 1  further comprising a flat section and an upturned section, wherein an outline of the flat section has approximately the same shape as a peripheral edge of the lower layer.  
     
     
         5 . The orthotic of  claim 1  further comprising a flat section and an upturned section, wherein an outline of the flat section closely follows a peripheral edge of the lower layer.  
     
     
         6 . The orthotic of  claim 1  further comprising a fabric layer, overlying the upper layer, that contains elemental silver configured to kill bacteria.  
     
     
         7 . A foot orthotic comprising: 
 an upper layer formed of a viscoelastic material;    a middle layer formed of a thermoplastic material with a softening temperature of about 55-80° C., whereby the orthotic can be pressed by a foot while the middle layer is in a heat-softened state during a custom-molding process but will not heat-soften during normal use; and    a lower layer formed of a material that will not heat-soften below about 90° C., whereby the lower layer will not heat-soften during the custom-molding process;    the layers being adhered together, and the orthotic being configured to be removably installed in a shoe.    
     
     
         8 . The orthotic of  claim 7  wherein the middle layer is stiffer than the upper and lower layers.  
     
     
         9 . The orthotic of  claim 7  further comprising a fabric layer, overlying the upper layer, that contains elemental silver configured to kill bacteria.  
     
     
         10 . The orthotic of  claim 7  further comprising a flat section and an upturned section, wherein an outline of the flat section has approximately the same shape as a peripheral edge of the lower layer.  
     
     
         11 . The orthotic of  claim 7  further comprising a flat section and an upturned section, wherein an outline of the flat section closely follows a peripheral edge of the lower layer.  
     
     
         12 . The orthotic of  claim 7  further comprising a thermal tag that changes color at a predetermined temperature, adhered to a surface of the orthotic.