Multi-plug design shoe insole

Abstract

An insole is provided for reducing peak plantar pressure on a foot. The insole includes a compressible pad having a plurality of holes extending from a bottom surface of the compressible pad and partially through the compressible pad. A plurality of compressible plugs is disposed in the plurality of holes, wherein the plurality of compressible plugs has a stiffness that is different than a stiffness of the compressible pad. The plurality of compressible plugs is concentrated in a reduced stiffness portion of the compressible pad that substantially corresponds to an area of peak plantar pressure on the foot.

1 . An insole for reducing plantar pressure on a portion of a foot, the insole comprising:
 a compressible pad having a stiffness;   a plurality of holes disposed within said compressible pad; and   a plurality of compressible plugs disposed in said plurality of holes, said plurality of compressible plugs having a different stiffness than said compressible pad.   
     
     
         2 . The insole of  claim 1 , wherein each of said compressible plugs has a cross-sectional area in a transverse plane of approximately one to twenty-nine square millimeters, wherein said plurality of compressible plugs are substantially cylindrical, and wherein said each of said compressible plugs has an effective diameter of approximately 1 mm to 6 mm. 
     
     
         3 . The insole of  claim 1 , wherein said plurality of holes are spaced approximately one to five millimeters apart. 
     
     
         4 . The insole of  claim 1 , wherein said plurality of holes and said plurality of compressible plugs are concentrated in a reduced stiffness portion of said compressible pad. 
     
     
         5 . The insole of  claim 1 , wherein each said hole extends from a bottom surface of said compressible pad and partially through said compressible pad. 
     
     
         6 . The insole of  claim 5 , wherein each said hole extends from said bottom surface of said compressible pad through approximately fifty to eighty percent of a thickness of said compressible pad. 
     
     
         7 . The insole of  claim 1  further comprising a plurality of stiffer compressible plugs disposed in a plurality of holes peripheral to the reduced stiffness portion of said compressible pad, wherein said plurality of stiffer compressible plugs are stiffer than said plurality of compressible plugs 
     
     
         8 . The insole of  claim 1 , wherein said compressible pad comprises a reduced stiffness portion that corresponds to an area of peak plantar pressure on the foot, and the plurality of compressible plugs is disposed within the reduced stiffness portion. 
     
     
         9 . The insole of  claim 8 , wherein said reduced stiffness portion is disposed in a forefoot portion of said compressible pad. 
     
     
         10 . The insole of  claim 9 , wherein said reduced stiffness portion of said compressible pad is positioned under a metatarsal head of the foot. 
     
     
         11 . The insole of  claim 1 , wherein said plurality of compressible plugs is arranged locally in a region of said compressible pad corresponding to an area of peak pressure on the foot. 
     
     
         12 . An insole for reducing peak plantar pressure on a foot, the insole comprising:
 a compressible pad having a plurality of holes extending from a bottom surface of said compressible pad and partially through said compressible pad;   a first plurality of compressible plugs having a stiffness greater than a stiffness of said compressible pad and disposed in a plurality of holes peripheral to a reduced stiffness portion of said compressible pad; and   a second plurality of compressible plugs having a stiffness that is less than the stiffness of said compressible pad and disposed in a plurality of holes throughout said reduced stiffness portion of said compressible pad.   
     
     
         13 . The insole of  claim 12 , wherein said plurality of compressible plugs are arranged in a substantially circular or oval pattern having a center that substantially corresponds to the center of an area of peak plantar pressure on the foot. 
     
     
         14 . The insole of  claim 13 , wherein said of said pattern is positioned substantially under a metatarsal head of the foot. 
     
     
         15 . The insole of  claim 12 , wherein said compressible plugs are substantially cylindrical. 
     
     
         16 . The insole of  claim 12 , wherein each said hole extends from said bottom surface of said compressible pad through approximately fifty to eighty percent of a thickness of said compressible pad. 
     
     
         17 . A method of reducing peak plantar pressure on a foot, said method comprising:
 providing a compressible pad having a plurality of holes extending therethrough;   providing a plurality of compressible plugs disposed in the plurality of holes, the plurality of compressible plugs having a stiffness that is different than a stiffness of the compressible pad; and   analyzing the foot to facilitate determining an optimal arrangement of the compressible plugs to create a reduced stiffness portion of the compressible pad.   
     
     
         18 . The method of  claim 17 , wherein the optimal arrangement of the compressible plugs in the reduced stiffness portion relieves peak plantar pressure on the foot while avoiding substantial secondary pressure peaks. 
     
     
         19 . The method of  claim 17 , wherein analyzing the foot further comprises positioning a subject in a sitting position with approximately half of the subject's weight on the subject's foot, and positioning a sensor on the plantar portion of the foot and wherein determining an optimal arrangement of the compressible plugs further comprises providing plugs having different stiffnesses. 
     
     
         20 . The method of  claim 19 , wherein determining an optimal arrangement of the compressible plugs further comprises arranging a first plurality of plugs around a periphery of the reduced stiffness portion of the compressible pad, and arranging a second plurality of plugs within the reduced stiffness portion of the compressible pad.