04223457 is referenced by 128 patents and cites 8 patents.

Heel supporting and cushioning member for footwear controlling the movement of foot/leg muscles in the form of removable, preferably disposable heel and foot shock absorber comprising a pliable coil filled with an elastomeric material resiliently flexing with the movement of the heel.

Title
Heel shock absorber for footwear
Application Number
5/944264
Publication Number
4223457
Application Date
September 21, 1978
Publication Date
September 23, 1980
Inventor
Alexander T Borgeas
129 W. Catalina Dr., Phoenix, 85013
AZ, US
Agent
Warren F B Lindsley
IPC
A43B 21/32
A43B 21/28
View Original Source