title: Accuracy and precision of gait events derived from motion capture in horses during walk and trot.
abstract: This study aimed to create an evidence base for detection of stance-phase timings from motion capture in horses. The objective was to compare the accuracy (bias) and precision (SD) for five published algorithms for the detection of hoof-on and hoof-off using force plates as the reference standard. Six horses were walked and trotted over eight force plates surrounded by a synchronised 12-camera infrared motion capture system. The five algorithms (A-E) were based on: (A) horizontal velocity of the hoof; (B) Fetlock angle and horizontal hoof velocity; (C) horizontal displacement of the hoof relative to the centre of mass; (D) horizontal velocity of the hoof relative to the Centre of Mass and; (E) vertical acceleration of the hoof. A total of 240 stance phases in walk and 240 stance phases in trot were included in the assessment. Method D provided the most accurate and precise results in walk for stance phase duration with a bias of 4.1% for front limbs and 4.8% for hind limbs. For trot we derived a combination of method A for hoof-on and method E for hoof-off resulting in a bias of -6.2% of stance in the front limbs and method B for the hind limbs with a bias of 3.8% of stance phase duration. We conclude that motion capture yields accurate and precise detection of gait events for horses walking and trotting over ground and the results emphasise a need for different algorithms for front limbs versus hind limbs in trot.
authors: University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Hojbakkegaard Allé 5, 2630 Taastrup, Denmark.
authors: Jenny Katrine
authors: JK
authors: Boye
authors: University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Hojbakkegaard Allé 5, 2630 Taastrup, Denmark.
authors: Maj Halling
authors: MH
authors: Thomsen
authors: The Royal Veterinary College, Department of Clinical Sciences and Services, Hawkshead Lane, North Mymms, AL9 7TA, United Kingdom.
authors: Thilo
authors: T
authors: Pfau
authors: University of Copenhagen, Faculty of Health and Medical Sciences, Department of Large Animal Sciences, Hojbakkegaard Allé 5, 2630 Taastrup, Denmark; The Royal Veterinary College, Department of Clinical Sciences and Services, Hawkshead Lane, North Mymms, AL9 7TA, United Kingdom. Electronic address: eo@sund.ku.dk.
authors: Emil
authors: E
authors: Olsen
mesh_terms: D000465:Algorithms; D000818:Animals; D001696:Biomechanical Phenomena; D005121:Extremities / Q000502:physiology*; D005260:Female; D005684:Gait; D006724:Hoof and Claw; D006736:Horses / Q000502:physiology*; D009038:Motion; D012016:Reference Values; D016138:Walking / Q000502:physiology*
keywords: Algorithm; Equine; Gait analysis; Gait event; Hoof-on; Locomotion; Method comparison; Stance