An instrumented insole for measurement of foot motion

A new insole for kinematic gait measurement is described. It consists of a micro-controller, 512kB of non-volatile memory, a miniature radio-frequency transceiver, a rechargeable power-source and various miniature sensors, particularly rate-gyroscopes and accelerometers. It is completely self-contained, with no extraneous connections or cables. The device may be used outside the laboratory; in which case readings from the sensors are logged to on-board memory and downloaded by radio telemetry to a personal computer (PC) for storage and analysis when the device is within range. The insole can store continuous data over many thousands of steps for field-based studies. Preliminary experiments show that the device can measure foot angles and is able to distinguish between normal, supinated and pronated gait.