Advantages of a simple contact switch for human locomotion.

A simple, inexpensive foot switch was fabricated to record the duration of surface contact for part or all of the foot during human locomotion. The device incorporated electrically conductive metallic foil in a thin foam insole. Advantages over a more conventional thick-soled sandal were documented for the same subjects by examining kinematic values (read from movie film) and electrical signal data (produced by the switch). A person's characteristic manner of placing and lifting the foot while wearing conventional shoes could in some instances distort readings of stance duration by many tens of msec, but the new switch assembly eliminated ambiguities of measurement and interpretation.