Photo demonstrates the still common transtibial (below knee) socket design with a very narrow pressure area between the back of the knee and just under the knee cap. This provides a firm lock to hold the stump off the bottom of the socket by overloading the soft tissues in these areas. The area in the back of the knee contains several major blood vessels and nerve pathways that we do not want to overload.

Photo below demonstrates the still common socket design with a very narrow pressure area between the front and back walls. This provides a firm lock to hold the stump off the bottom of the socket by overloading the soft tissues in these areas (upper part of the front wall). This area contains several major blood vessels and nerve pathways that we do not want to overload. These sockets are difficult to control because there is no correct position of th femur (large bone in the leg).