title: Validation of distal limb mounted inertial measurement unit sensors for stride detection in Warmblood horses at walk and trot.
abstract: BACKGROUND
  Inertial measurement unit (IMU) sensor-based techniques are becoming more popular in horses as a tool for objective locomotor assessment.
  
  
  OBJECTIVE
  To describe, evaluate and validate a method of stride detection and quantification at walk and trot using distal limb mounted IMU sensors.
  
  
  METHODS
  Prospective validation study comparing IMU sensors and motion capture with force plate data.
  
  
  METHODS
  A total of seven Warmblood horses equipped with metacarpal/metatarsal IMU sensors and reflective markers for motion capture were hand walked and trotted over a force plate. Using four custom built algorithms hoof-on/hoof-off timing over the force plate were calculated for each trial from the IMU data. Accuracy of the computed parameters was calculated as the mean difference in milliseconds between the IMU or motion capture generated data and the data from the force plate, precision as the s.d. of these differences and percentage of error with accuracy of the calculated parameter as a percentage of the force plate stance duration.
  
  
  RESULTS
  Accuracy, precision and percentage of error of the best performing IMU algorithm for stance duration at walk were 28.5, 31.6 ms and 3.7% for the forelimbs and -5.5, 20.1 ms and -0.8% for the hindlimbs, respectively. At trot the best performing algorithm achieved accuracy, precision and percentage of error of -27.6/8.8 ms/-8.4% for the forelimbs and 6.3/33.5 ms/9.1% for the hindlimbs.
  
  
  CONCLUSIONS
  The described algorithms have not been assessed on different surfaces.
  
  
  CONCLUSIONS
  Inertial measurement unit technology can be used to determine temporal kinematic stride variables at walk and trot justifying its use in gait and performance analysis. However, precision of the method may not be sufficient to detect all possible lameness-related changes. These data seem promising enough to warrant further research to evaluate whether this approach will be useful for appraising the majority of clinically relevant gait changes encountered in practice.
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
authors.forename: F M
authors.initials: FM
authors.lastname: Bragança
authors.affiliation: Inertia Technology B.V., Enschede, the Netherlands.|Department of Computer Science, Pervasive Systems Group, University of Twente, Enschede, the Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Bosch
authors.affiliation: Rosmark Consultancy, Wekerom, the Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Voskamp
authors.affiliation: Inertia Technology B.V., Enschede, the Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Marin-Perianu
authors.affiliation: Inertia Technology B.V., Enschede, the Netherlands.
authors.forename: B J
authors.initials: BJ
authors.lastname: Van der Zwaag
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht, the Netherlands.
authors.forename: J C M
authors.initials: JCM
authors.lastname: Vernooij
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
authors.forename: P R
authors.initials: PR
authors.lastname: van Weeren
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.|Department of Surgery and Anaesthesiology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Back
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015374:Biosensing Techniques / Q000295:instrumentation / Q000662:veterinary*; D005552:Forelimb / Q000502:physiology; D005684:Gait / Q000502:physiology*; D006724:Hoof and Claw; D006736:Horses / Q000502:physiology*; D011446:Prospective Studies; D016138:Walking / Q000502:physiology*
keywords: gait analysis; horse; inertial measurement unit; kinematics; stride events