Traditionally, veterinarians have had to rely on subjective visual assessment as the only method available for performing lameness diagnosis, however, subjective visual evaluation of horses with mild or multiple limb lameness is difficult. Agreement between veterinarians in these cases is poor. This is not the fault of the veterinarian and not a reflection of poor ability but a limitation of the human eye’s temporal resolution. Increasing the temporal resolution by high-frequency capturing of movement asymmetry using wirelessly transmitted data from body-mounted inertial sensors is a solution to improve the veterinarian’s ability to detect and quantify lameness in horses.
Sensor Placement: One sensor is placed on the horse’s head (attached to the halter); one is located on the pelvis (with non-residue adhesive strips); and the third is attached to the front right hoof (with an elastic bandage wrap).
The “Lameness Locator” objectively detects and quantifies body movement asymmetry in a horse using small, body-mounted inertial sensors and a hand-held tablet PC. Instrumentation of the horse is quick, easy, and completely non-invasive. Data collection is in real time and veterinarians are free to perform their usual lameness evaluation routine without distraction.
The proprietary Lameness Locator analysis uses the motion data transmitted by the sensors and algorithms developed during 18 years of gait analysis of sound and lame horse movement at the University of Missouri E. Paige Laurie Equine Lameness Program. That research used treadmills and high speed cameras to mathematically characterize normal and impaired gait. Translational research adapted the system for commercial deployment as a convenient, robust, miniaturized system.
This unique set of data analysis algorithms helps to determine the affected limb or limbs, the severity of lameness within each limb and the timing of peak lameness pain within the stride cycle of each limb.
Results are then presented to the veterinarian in an intuitive graphical interface that is easy to interpret and report to clients.
Current users of Lameness Locator find that it is most helpful for horses with mild lameness, multiple limb lameness, compensatory lameness, quantifying the effectiveness of nerve and joint blocks, confirming the incidental nature of equivocal imaging abnormalities, and developing a further diagnostic approach based on the type of lameness (impact or pushoff) exhibited. It is also a great way to document soundness in a pre-purchase evaluation.
An initial lameness evaluation with the Lameness Locator takes around 20 minutes. The system components are three sensors, an extended battery life tablet PC for field use, software pre-loaded on the tablet PC, and a module for charging the batteries in the sensors. The sensors are about the size of a small matchbox and contain a MEMS accelerometer/ gyroscope.
The horse is trotted and data is transmitted wirelessly in real time and analyzed by proprietary algorithms in the tablet PC. The effective transmission range is 100 yards or more, though a result is usually achieved in 30 – 50 yards. The comprehensive lameness assessment is immediately available to the practitioner.