En kvalitativ utvärdering av det accelerometerbaserade hältdetektionssystemet "Lameness Locator"

Abstract: Background: Evaluation of lameness in horses is traditionally performed by a veterinarian who subjectively evaluates the movements of the horse. Accordingly, lameness diagnosis varies with the veterinarian and circumstances for which the horse is examined. Research within the area has long tried to establish an objective and standardized method for lamenessevaluation in horses. Several methods have been shown to be reliable and are used regularly within research, for example measurement of forces between the hoof and ground, and measurement of movements with high speed cameras or accelerometers. However these methods require considerable preparation, standardization, and expensive equipment as well as produce large amounts of data that are incomprehensible for the clinician. Consequently, up until now the implementation of objective lameness methodologies to a normal clinical setting has been prohibited. A simplified accelerometersystem with associated software for userfriendly results has been developed at University of Missouri, USA. The system comprizes two accelerometers and one gyrometer that sends data to a portable computer. The data analysed is then presented as a summary of asymmetries arising from the head or pelvis and which limb that can be connected to that asymmetry. It also measures magnitude and significance of the assymetries. Purpose: To evaluate "Lameness Locator´s" usefulness in clinical situations, on horses in everyday work and in high speed during swedish conditions and to identify sources of error that can influence the user´s diagnosis Procedure: The system was evaluated during three situations Data were collected from a horse, equipped with sensors, that was evaluated for lameness including lounging, flexion tests and diagnostic blocks. The result was compared with the assessing veterinarian. Another horse was evaluated in a field study during work at a trotting track and again, data were collected during the entire investigation. This was also an occasion to test the system's ability to detect lameness at high speed. A third experiment concentrated on evaluating the system's ability to detect asymmetries at high speed in trotters. Three horses, fully fit for competition, were driven at high speed and movement disturbances were provoked by a weight attached to the hoofwall. Results and discussion: Lameness Locator´s results correlated well to the ongoing lameness-evaluation. For both horses horses that came into the clinic the results according to the system was the same as for the veterinarian´s evaluation. In the experiment with weight-induced asymmetries, the participating horses turned out to be initially lame which influenced the result. In two of the three horses the lameness was exaggerated by weighting the lame limb. "Lameness Locator" could detect lamenesses irrespective of footing or speed. Even compensatory movements are detected and presented within the system, which requires knowledge about this in order to correctly evaluate the results.