| 1. |
- Haubro Andersen, Pia, et al.
(författare)
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Towards Machine Recognition of Facial Expressions of Pain in Horses
- 2021
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Ingår i: Animals. - : MDPI. - 2076-2615. ; 11:6
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Forskningsöversikt (refereegranskat)abstract
- Simple Summary Facial activity can convey valid information about the experience of pain in a horse. However, scoring of pain in horses based on facial activity is still in its infancy and accurate scoring can only be performed by trained assessors. Pain in humans can now be recognized reliably from video footage of faces, using computer vision and machine learning. We examine the hurdles in applying these technologies to horses and suggest two general approaches to automatic horse pain recognition. The first approach involves automatically detecting objectively defined facial expression aspects that do not involve any human judgment of what the expression "means". Automated classification of pain expressions can then be done according to a rule-based system since the facial expression aspects are defined with this information in mind. The other involves training very flexible machine learning methods with raw videos of horses with known true pain status. The upside of this approach is that the system has access to all the information in the video without engineered intermediate methods that have filtered out most of the variation. However, a large challenge is that large datasets with reliable pain annotation are required. We have obtained promising results from both approaches. Automated recognition of human facial expressions of pain and emotions is to a certain degree a solved problem, using approaches based on computer vision and machine learning. However, the application of such methods to horses has proven difficult. Major barriers are the lack of sufficiently large, annotated databases for horses and difficulties in obtaining correct classifications of pain because horses are non-verbal. This review describes our work to overcome these barriers, using two different approaches. One involves the use of a manual, but relatively objective, classification system for facial activity (Facial Action Coding System), where data are analyzed for pain expressions after coding using machine learning principles. We have devised tools that can aid manual labeling by identifying the faces and facial keypoints of horses. This approach provides promising results in the automated recognition of facial action units from images. The second approach, recurrent neural network end-to-end learning, requires less extraction of features and representations from the video but instead depends on large volumes of video data with ground truth. Our preliminary results suggest clearly that dynamics are important for pain recognition and show that combinations of recurrent neural networks can classify experimental pain in a small number of horses better than human raters.
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| 2. |
- Egenvall, Agneta, et al.
(författare)
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Lungeing on hard and soft surfaces: Movement symmetry of trotting horses considered sound by their owners
- 2016
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 48, s. 83-89
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Tidskriftsartikel (refereegranskat)abstract
- Reasons for performing studyLungeing is often part of the clinical lameness examination. The difference in movement symmetry, which is a commonly employed lameness measure, has not been quantified between surfaces.ObjectivesTo compare head and pelvic movement symmetry between surfaces and reins during lungeing.Study designQuantitative gait analysis in 23 horses considered sound by their owners.MethodsTwenty-three horses were assessed in-hand and on the lunge on both reins on hard and soft surfaces with inertial sensors. Seven movement symmetry parameters were quantified and used to establish 2 groups, namely symmetrical (n = 9) and forelimb-lame horses (n = 14), based on values from straight-line assessment. Movement symmetry values for left rein measurements were side corrected to allow comparison of the amount of movement symmetry between reins. A mixed model (P<0.05) was used to study effects on movement symmetry of surface (hard/soft) and rein (inside/outside with respect to movement symmetry on the straight).ResultsIn forelimb-lame horses, surface and rein were identified as significantly affecting all head movement symmetry measures (rein, all P<0.0001; surface, all P<0.042). In the symmetrical group, no significant influence of surface or rein was identified for head movement symmetry (rein, all P>0.245; surface, all P>0.073). No significant influence of surface or rein was identified for any of the pelvic movement symmetry measures in either group.ConclusionsWhile more symmetrical horses showed a consistent amount of movement symmetry across surfaces/reins, horses objectively quantified as lame on the straight showed decreased movement symmetry during lungeing, in particular with the lame limb on the inside of a hard circle. The variation within group questions straight-line movement symmetry as a sole measure of lameness without quantification of movement symmetry on the lunge, ideally on hard and soft surfaces to evaluate differences between reins and surfaces. In future, thresholds for lungeing need to be determined using simultaneous visual and objective assessment.
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| 3. |
- Egenvall, Agneta, et al.
(författare)
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Rein Tension During Transitions
- 2016
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 48, s. 26-26
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Hammarberg, Marie, et al.
(författare)
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Rater agreement of visual lameness assessment in horses during lungeing
- 2016
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 48, s. 78-82
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Tidskriftsartikel (refereegranskat)abstract
- Reasons for performing study Lungeing is an important part of lameness examinations as the circular path may accentuate low-grade lameness. Movement asymmetries related to the circular path, to compensatory movements and to pain make the lameness evaluation complex. Scientific studies have shown high inter-rater variation when assessing lameness during straight line movement. Objectives The aim was to estimate inter- and intra-rater agreement of equine veterinarians evaluating lameness from videos of sound and lame horses during lungeing and to investigate the influence of veterinarians' experience and the objective degree of movement asymmetry on rater agreement. Study design Cross-sectional observational study. Methods Video recordings and quantitative gait analysis with inertial sensors were performed in 23 riding horses of various breeds. The horses were examined at trot on a straight line and during lungeing on soft or hard surfaces in both directions. One video sequence was recorded per condition and the horses were classified as forelimb lame, hindlimb lame or sound from objective straight line symmetry measurements. Equine veterinarians (n = 86), including 43 with >5 years of orthopaedic experience, participated in a web-based survey and were asked to identify the lamest limb on 60 videos, including 10 repeats. The agreements between (inter-rater) and within (intra-rater) veterinarians were analysed with statistics (Fleiss, Cohen). Results Inter-rater agreement was 0.31 (0.38/0.25 for experienced/less experienced) and higher for forelimb (0.33) than for hindlimb lameness (0.11) or soundness (0.08) evaluation. Median intra-rater agreement was 0.57. Conclusions Inter-rater agreement was poor for less experienced raters, and for all raters when evaluating hindlimb lameness. Since identification of the lame limb/limbs is a prerequisite for successful diagnosis, treatment and recovery, the high inter-rater variation when evaluating lameness on the lunge is likely to influence the accuracy and repeatability of lameness examinations and, indirectly, the efficacy of treatment.
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| 5. |
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| 6. |
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| 7. |
- Eisersiö, Marie, et al.
(författare)
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A snapshot of the training schedule for 8 professional riders riding dressage
- 2015
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Ingår i: Comparative Exercise Physiology. - 1755-2540 .- 1755-2559. ; 11, s. 35-46
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to document and categorise riding sessions, carried out by professional riders, by describing the riding sessions according to gait, ridden track, lateral movements, rider position in the saddle and rein length. These data were then analysed relative to horse and rider characteristics, e.g. educational level of horse and rider, time in training and laterality of the horse. Eight professional riders riding 3 familiar horses each participated in the study and the riders were asked to demonstrate their normal routine for flatwork/dressage with each horse. The whole training session was video recorded. Video recordings were scrutinised and data were categorised and analysed. Mixed models were used for the statistical analysis, including rider as random effect. The median length of the riding sessions were 31 min. The riders spent 38% of the riding session at the walk, 39% at the trot, 8% at left lead canter and 9% at the right lead canter. The riders devoted 28-29% of the riding session to riding straight, turning left and turning right and 8% to riding lateral movements. The ridden exercises performed and the duration of the exercises was to a large extent connected to the educational level of the horse and its time in training with the rider. More work at the canter and lateral movements at the trot were included for upper level horses compared to lower level horses. Horses in training for more than one year, compared to less than one year, were ridden for longer durations at the canter and shorter durations at the trot. The disposition of riding sessions needs further investigation. In particular, large scale epidemiological studies of orthopaedic injuries need to consider the daily riding sessions in detail.
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| 8. |
- Lawin, Felix Jaremo, et al.
(författare)
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Is Markerless More or Less? : Comparing a Smartphone Computer Vision Method for Equine Lameness Assessment to Multi-Camera Motion Capture
- 2023
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Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Lameness, an alteration of the gait due to pain or dysfunction of the locomotor system, is the most common disease symptom in horses. Yet, it is difficult for veterinarians to correctly assess by visual inspection. Objective tools that can aid clinical decision making and provide early disease detection through sensitive lameness measurements are needed. In this study, we describe how an AI-powered measurement tool on a smartphone can detect lameness in horses without the need to mount equipment on the horse. We compare it to a state-of-the-art multi-camera motion capture system by simultaneous, synchronised recordings from both systems. The mean difference between the systems' output of lameness metrics was below 2.2 mm. Therefore, we conclude that the smartphone measurement tool can detect lameness at relevant levels with easy-of-use for the veterinarian. Computer vision is a subcategory of artificial intelligence focused on extraction of information from images and video. It provides a compelling new means for objective orthopaedic gait assessment in horses using accessible hardware, such as a smartphone, for markerless motion analysis. This study aimed to explore the lameness assessment capacity of a smartphone single camera (SC) markerless computer vision application by comparing measurements of the vertical motion of the head and pelvis to an optical motion capture multi-camera (MC) system using skin attached reflective markers. Twenty-five horses were recorded with a smartphone (60 Hz) and a 13 camera MC-system (200 Hz) while trotting two times back and forth on a 30 m runway. The smartphone video was processed using artificial neural networks detecting the horse's direction, action and motion of body segments. After filtering, the vertical displacement curves from the head and pelvis were synchronised between systems using cross-correlation. This rendered 655 and 404 matching stride segmented curves for the head and pelvis respectively. From the stride segmented vertical displacement signals, differences between the two minima (MinDiff) and the two maxima (MaxDiff) respectively per stride were compared between the systems. Trial mean difference between systems was 2.2 mm (range 0.0-8.7 mm) for head and 2.2 mm (range 0.0-6.5 mm) for pelvis. Within-trial standard deviations ranged between 3.1-28.1 mm for MC and between 3.6-26.2 mm for SC. The ease of use and good agreement with MC indicate that the SC application is a promising tool for detecting clinically relevant levels of asymmetry in horses, enabling frequent and convenient gait monitoring over time.
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| 9. |
- Persson-Sjödin, Emma, et al.
(författare)
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Effect of meloxicam treatment on movement asymmetry in riding horses in training
- 2019
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- Quantitative gait analysis has revealed that a large proportion of horses in training, perceived as free from lameness by their owners, show movement asymmetries of equal magnitude to horses with mild clinical lameness. Whether these movement asymmetries are related to orthopaedic pain and/or pathology has yet to be further investigated. Therefore, the objective of this study was to determine whether movement asymmetries in riding horses in training are affected by anti-inflammatory treatment with meloxicam. In a crossover design, horses were treated with meloxicam or placebo for four days respectively, with a 14-16 day washout period between treatments. Objective movement analysis utilising body mounted accelerometers was performed on a hard and a soft surface before and on day four of each treatment. A trial mean was calculated for the differences between the two vertical displacement minima and maxima of head (HDmin, HDmax) and pelvis (PDmin, PDmax) per stride. Horses (n = 66) with trial mean asymmetries greater than 6 mm for HDmin or HDmax, or more than 3 mm for PDmin or PDmax, at baseline were included. The difference before and after each treatment in the measured movement asymmetry was assessed with linear mixed models. Treatment with meloxicam did not significantly affect the movement asymmetry in any of the models applied (all p>0.30). These results raise new questions: are the movement asymmetries in riding horses in training simply expressions of biological variation or are they related to pain/dysfunction that is non-responsive to meloxicam treatment?
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| 10. |
- Rhodin, Marie, et al.
(författare)
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Timing of Vertical Head, Withers and Pelvis Movements Relative to the Footfalls in Different Equine Gaits and Breeds
- 2022
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Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Movement symmetry of the head and pelvis are used to measure lameness in horses in trot. Although head, pelvis and limb movements have been described, less is known about the temporal relationships between them. This information is needed to understand how the movements change with lameness. This is particularly relevant in gaited horses, such as the Icelandic horse that perform gaits such as tolt and pace, which are challenging to evaluate. This study used inertial measurement units to investigate head, withers and pelvis motion relative to limb movements in Icelandic, Warmblood and Iberian horses. Limb movements, together with vertical movements and lowest/highest positions of the head, withers and pelvis were calculated, and the relative timing of the events was compared across breeds. Additionally, data for tolt and pace were collected and evaluated in ridden Icelandic horses. For all gaits except walk and pace, the lowest/highest positions of the head/withers/pelvis were closely temporally related to midstance and hoof-off, respectively. Pelvic and withers total range of motion differed between all breeds. The Icelandic horses showed shorter stride duration and smaller movements of the upper body than the other breeds at trot, which may explain why lameness evaluation in this breed is challenging. Knowledge of vertical motion patterns of the axial body segments is a prerequisite for the development of algorithms used in automated detection of lameness. To date, the focus has been on the trot. This study investigates the temporal synchronization between vertical motion of the axial body segments with limb kinematic events in walk and trot across three popular types of sport horses (19 Warmbloods, 23 Iberians, 26 Icelandics) that are known to have different stride kinematics, and it presents novel data describing vertical motion of the axial body segments in tolting and pacing Icelandic horses. Inertial measurement unit sensors recorded limb kinematics, vertical motion of the axial body at all symmetrical gaits that the horse could perform (walk, trot, tolt, pace). Limb kinematics, vertical range of motion and lowest/highest positions of the head, withers and pelvis were calculated. For all gaits except walk and pace, lowest/highest positions of the pelvis and withers were found to be closely related temporally to midstance and start of suspension of the hind/fore quarter, respectively. There were differences in pelvic/withers range of motion between all breeds where the Icelandic horses showed the smallest motion, which may explain why lameness evaluation in this breed is challenging.
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