Comparing pressure measurement systems and a force platform as tools for equine gait analysis

Abstract

Objective assessment of lameness in the horse has been well established through testing with force platforms. The force platform measures ground reaction forces in three orthogonal directions: mediolateral (Fx), craniocaudal (Fy) and vertical (Fz). Testing with force platforms has shown researchers that this technology is capable of providing accurate and reliable quantitative data for use in lameness assessment. However, the cost of force platform systems, setup and training as well as the lack of mobility of the systems has driven researchers to look for alternative systems which are user-friendly, less expensive and capable of field use rather than a laboratory environment. Pressure measurement systems were designed for use in the human podiatric profession in order to provide a quick and easy method for determining vertical ground reaction forces, contact area and plantar pressures. Previous testing of the F-Mat system (Tekscan, Boston, MA) showed accurate calibration was extremely important for optimum performance and that standard sensor manufacturing caused sensors to saturate under the loads of horses therefore not providing accurate and reliable data. However, testing of the equine F-Scan system (Tekscan, Boston, MA) showed that pressure measurement systems were capable of assessing lameness in the horse on a treadmill. With careful calibration and proper design of sensors specifically for horses, tests were designed to compare the ability of the F-Mat and Equine F-Scan mobile units (a system capable of recording pressure measurements from the hooves without being connected directly to a computer) to a force platform to measure vertical ground reaction forces. Results from this study indicate that proper sensor design and calibration help the pressure systems to measure vertical ground reaction forces with values similar to a force platform. Statistical tests show the pressure systems are not as precise as the force platform for repeated measurements and the accuracy of the mobile unit can be comparable to the force platform but the F-Mat was not. This study provided proof that the equine mobile unit could quantitatively assess lameness in the field. Further development of the mobile unit will make the system easier to attach to the horse and use. Thereby providing researchers and practitioners with an alternative to the force platform than can be used in the field to provide accurate and reliable data to quantitatively assess lameness in the horse.