1
Marc H Ratzlaff, Barrie D Grant, John M Frame: Systems for measurement and analysis of forces exerted during human locomotion. Washington State University Research Foundation, Wells St John & Roberts, March 21, 1989: US04814661 (294 worldwide citation)

Systems including piezoelectric sensor elements advantageously mounted between supporting hard plastic material of various types or other mechanically similar materials. The sensor can further be supported by backup plate structures. Some backup plates show full shoe coverage and others show partial ...


2
Marc H Ratzlaff, John M Frame, Barrie D Grant: Electronic animal hoof force detection systems. Washington State University Research Foundation, Wells St John & Roberts, October 27, 1987: US04703217 (13 worldwide citation)

Hoof force detection apparatus having shoe portions adapted for connecting to the hooves of hoofed animals. The apparatus also includes piezoelectric elements mounted on sensor mounting sections which are connected to the shoe portions using flexion joints. The flexion joints allow forces applied to ...