Transtibial socket for external prosthesis

Abstract

A prosthetic hard socket has a modified curvature and/or shape that improves rotational control, comfort, and range of motion including even full extension or hyperextension. The hard socket eliminates or de-emphasizes the patellar bar, to eliminate or reduce pressure on the wearer's patellar tendon, and enhances support of the anterior tibial condyle and/or tibial tubercle. Thus, the patellar tendon preferably is not weight-bearing. A lowered socket edge and/or a gap in the socket wall in the region of the patellar tendon prevents the hard structure of the socket from directly supporting or pressing upon the patellar tendon. Inwardly-protruding regions on each side of the lowered edge/gap help “capture” or otherwise press on a portion of the tibia. A flexible and/or cushioning member may be placed in the gap/trough.

1 . An external below-the-knee prosthesis comprising:
 a socket hard wall surrounding and defining a socket interior space and an upper edge defining an opening for receiving a residual limb of a wearer into the socket interior space, the upper edge having an uppermost portion;   wherein said socket hard wall is adapted to avoid contact with the patellar tendon of the wearer by comprising a downwardly-extending notch in the upper edge of the socket hard wall, the notch being defined by generally-vertically-extending, spaced-apart notch sides and a lowermost part that is a distance of 4-6 inches below said uppermost portion of the upper edge of the socket hard wall; and   a flexible member attached to said socket hard wall and extending between said notch sides for contacting the wearer's residual limb or liner-covered residual limb.   
     
     
         2 . A socket as in  claim 1 , wherein the flexible member does not encircle the residual limb. 
     
     
         3 . A socket as in  claim 1 , wherein the flexible member does not extend underneath the distal end of the residual limb. 
     
     
         4 . A socket as in  claim 1 , wherein the flexible member is glued to the hard socket. 
     
     
         5 . A socket as in  claim 1 , wherein the flexible member is a patch of flexible fabric. 
     
     
         6 . A socket as in  claim 1 , wherein the notch has a width of 2-3 inches between said spaced-apart notch sides. 
     
     
         7 . A socket as in  claim 1 , wherein the socket hard wall comprises two recesses that extend inward into the interior space of the socket on each of two sides of said notch, for pressing against the wearer's anterior tibial condyle. 
     
     
         8 . A socket as in  claim 1 , wherein the socket hard wall of the socket comprises no patellar bar for pressing against the wearer's patellar tendon. 
     
     
         9 . A socket as in  claim 1 , wherein the notch is V-shaped. 
     
     
         10 . A method of making a below-the-knee prosthesis socket, the method comprising:
 forming a hard socket wall having a top edge having an uppermost portion and a notch extending axially downward a distance of 4-6 lower than said uppermost portion to provide a gap in the socket wall in which a wearer's patellar tendon resides when the wearer's residual limb is in said socket, so that no portion of the hard socket wall presses against the patellar tendon during use of the socket, and the method further comprising attaching a flexible patch to the hard socket so that the flexible patch extends across the notch generally parallel to the hard socket wall, so that said flexible patch contacts the wearer's liner-covered residual limb at the patellar tendon.   
     
     
         11 . A method as in  claim 10 , wherein the flexible patch does not encircle the wearer's residual limb. 
     
     
         12 . A method as in  claim 10 , wherein the notch is 2-3 inches wide. 
     
     
         13 . A method of  claim 10 , further comprising forming indentations in the hard socket wall on each of two sides of the notch, wherein said indentations protrude into the interior space of the socket to press against the wearer's anterior tibial condyle. 
     
     
         14 . A method of  claim 10 , wherein said hard socket comprises no patellar tendon bar. 
     
     
         15 . A method of  claim 10 , wherein said hard socket comprises no horizontal ledge in the interior surface of the hard socket wall at the patellar tendon region of the residual limb. 
     
     
         16 . A method of  claim 10 , wherein the notch is V-shaped.