Integrated pressure-force-kinematics measuring system for the characterisation of plantar foot loading during locomotion

Plantar pressure, ground reaction force and body-segment kinematics measure ments are largely used in gait analysis to characterise normal and abnormal function of the human foot The combination of all these data together prov ides a more exhaustive, detailed and accurate view of foot loading during a ctivities than traditional measurement systems alone do. A prototype system is presented that integrates a pressure platform, a force platform and a 3 D anatomical tracking system to acquire combined information about foot fun ction and loading. A stereophotogrammetric system and an anatomically based protocol for foot segment kinematics is included in a previously devised p iezo-dynamometric system that combines pressure and force measurements. Exp erimental validation tests are carried out to check for both spatial and ti me synchronisation. Misalignment of the three systems is found to be within 6.0, 5.0 and 1.5 mm for the stereophotogrammetric system, force platform a nd pressure platform, respectively The combination of position and pressure data allows for a more accurate selection of plantar foot subareas on the footprint. Measurements are also taken on five healthy volunteers during le vel walking to verify the feasibility of the overall experimental protocol. Four main subareas are defined and identified, and the relevant vertical a nd shear force data are computed The integrated system is effective when th ere is a need for loading measurements in specific plantar foot subareas. T his is attractive both in clinical assessment and in biomechanics research.