Article

Subjective Gait Assessment of 57 Sports Horses in Normal Work: A Comparison of the Response to Flexion Tests, Movement in Hand, on the Lunge, and Ridden

January 2016
Journal of Equine Veterinary Science 38(suppl 18)

DOI:10.1016/j.jevs.2015.12.012

Authors:

Sue Dyson

Independent consultant

Line Greve

Evidensia Specialist Equine Hospital Helsingborg

Historically lameness has been evaluated in hand or on the lunge, but some lamenesses may only be apparent ridden. The objectives were to compare the response to flexion tests, movement in hand, on the lunge and ridden in sports horses in regular work, assumed to be sound by the owners. It was hypothesised that lameness may be apparent in ridden horses that was not detectable in hand or on the lunge. Fifty-seven sport horses in regular work and assumed to be sound were assessed prospectively in hand, on the lunge on both soft and firm surfaces and ridden. Flexion tests of all four limbs were performed. Lameness was graded (0-8) under each circumstance in which the horse was examined and after each flexion test.

Riding Soundness—Comparison of Subjective With Objective Lameness Assessments of Owner-Sound Horses at Trot on a Treadmill

Article

Full-text available

Nov 2020
J EQUINE VET SCI

Lameness is a symptom indicative of pain or injury of the locomotor apparatus. Lame horses generally should not be ridden. However, owners’ ability to assess lameness has been questioned. This study’s aim was to use subjective lameness assessments and objective gait analysis to generate a descriptive overview of movement and weight-bearing asymmetries of owner-sound riding horses. 235 horses were subjectively assessed in a field study, and the owner’s perception of their horse’s orthopedic health was recorded through an online survey. 69 horses were re-evaluated by gait analysis at an equine hospital. During trot on an instrumented treadmill, the gait was scored by a veterinarian using lameness grades from 0/5 (sound) to 3/5 (moderate lameness visible at trot). Movement asymmetry of the head (HDmin) and pelvis (PDmin) and weight-bearing asymmetry were quantified simultaneously. The prevalence of subjectively scored lameness grade ≥2/5 in one or more limbs was 55% during study part 1 and 74% during study part 2. Movement asymmetry of the head and/or pelvis exceeding HDmin ≥12 mm and/or PDmin ≥6 mm was found in 57% of the horses. 58% showed weight-bearing asymmetries between contralateral front and/or hind limbs of ≥3% body mass. Gait analysis showed considerable variability of movement and weight-bearing asymmetry values, sometimes independent of the clinical lameness grade, especially in the forehand. Several horses with lameness grade ≤1/5 had asymmetry values greater than mentioned thresholds. The analysis of movement and weight-bearing asymmetry revealed that these objective variables did not necessarily act uniformly and therefore should be interpreted with caution.

Gait abnormalities and ridden horse behaviour in a convenience sample of the United Kingdom ridden sports horse and leisure horse population

Article

Oct 2020
EQUINE VET EDUC

The objectives of this study were to compare horses’ gaits in hand and when ridden; to assess static and dynamic saddle fit for each horse and rider; to apply the Ridden Horse Pain Ethogram (RHpE) and relate the findings to gait abnormalities consistent with musculoskeletal pain, rider position and balance and saddle fit; and to document noseband use and its relationship with mouth opening during ridden exercise. Data were acquired prospectively from a convenience sample of horses believed by their owners to be working comfortably. All assessments were subjective. Gait in hand and when ridden were evaluated independently, by two assessors, and compared using McNemar’s test. Static tack fit and noseband type were recorded. Movement of the saddle during ridden exercise, rider position, balance and size relative to the saddle was documented. RHpE scores were based on assessment of video recordings. Multivariable Poisson regression analysis was used to determine factors which influenced the RHpE scores. Of 148 horses, 28.4% were lame in hand, whereas 62.2% were lame ridden (P<0.001). Sixty per cent of horses showed gait abnormalities in canter. The median RHpE score was 8/24 (interquartile range 5, 9; range 0, 15). There was a positive association between lameness and the RHpE score (P<0.001). Riding School horses had higher RHpE scores compared with General Purpose horses (P = 0.001). Saddles with tight tree points (P = 0.001) and riders seated at the back of the saddle rather than the middle (P = 0.001) were associated with higher RHpE scores. Horses wearing crank cavesson compared with cavesson nosebands had higher RHpE scores (P = 0.006). There was no difference in mouth opening, as defined by the RHpE, in horses with a noseband with the potential to restrict mouth opening, compared with a correctly fitted cavesson noseband, or no noseband. It was concluded that lameness or gait abnormalities in canter may be missed unless horses are assessed ridden.

Determination of Equine Behaviour in Subjectively Non-Lame Ridden Sports Horses and Comparison with Lame Sports Horses Evaluated at Competitions

Article

Full-text available

Jun 2024

Simple Summary The Ridden Horse Pain Ethogram (RHpE) comprising 24 behaviours was developed to facilitate the identification of musculoskeletal pain. A RHpE score ≥8/24 indicates the likely presence of musculoskeletal pain. The RHpE was applied to 1358 horses in competition, with a comparison of behaviours in lame and non-lame horses. In a large majority of the non-lame horses, the head was still, the front of the head was in a vertical position or behind the vertical, the eyes were open with no exposure of the sclera, all of the tongue remained within the oral cavity, the bit was symmetrically positioned, and the tail was held straight and carried freely. Horses maintained a regular rhythm and speed in all paces, moving straight on two tracks. Non-lame horses initiated canter with the correct leading forelimb and did not change legs in front or behind; there were no spontaneous changes of gait, no repeated forelimb or hindlimb stumbling, and an absence of bilateral hindlimb toe drag. Horses followed the direction of the rider’s cues, with no spooking, and went forward willingly, with an absence of bucking or rearing. Recognition of how a non-lame horse usually behaves may enhance equine welfare and improve training practices. Abstract The Ridden Horse Pain Ethogram (RHpE) was developed to facilitate the identification of musculoskeletal pain. The aim of the current study was to collate behavioural data using the RHpE from horses at competitions assumed by their owners and/or riders to be fit for competition. The objectives were to quantify the frequency of occurrence of behaviours in pain-free horses and those with lameness or abnormalities of canter and to determine any differences between disciplines and levels of competition. The RHpE was applied to 1358 horses competing in Grand Prix (GP) dressage (n = 211), 5* three-day events (TDE) (n = 137), or low-level one-day events (ODE) (n = 1010). The median RHpE score for all horses was 4 (interquartile range [IQR] 2, 5; range 0, 12) and the median lameness grade was 0 (IQR 0, 1; range 0, 4). The Kruskal–Wallis test, followed by Dunn’s test for pairwise comparisons, found a difference in median RHpE scores between low-level ODE and GP dressage (p = 0.001), but not between 5* TDE and low-level ODE (p = 0.09) or between GP dressage and 5* TDE (p = 1.00). The median RHpE score was highest for low-level ODE. The Chi-square/Fisher’s exact test identified a significant difference in prevalence of most of the 24 behaviours of the RHpE in non-lame compared with lame horses. Recognition of the behaviours of non-lame horses may improve equine welfare and performance, and rider comfort, confidence, and safety.

Agreement between two traditional lunging protocols for physical fitness training in untrained horses

Preprint

Jun 2024

Background: Lunging is a training method that is performed in a round pen or on a lunge line. However, there is no consensus on applying lunging techniques for physical fitness training. Objectives: To investigate the effort intensity, autonomic responses, and method agreement in applying different lunging protocols to untrained horses. Study design: A non-randomised control trial. Methods: Sixteen untrained horses (aged 13.6 ± 6.3 years and weighing 358 ± 47.4 kg) were studied. Each horse was lunged with a similar programme on a lunge line and, subsequently, in a round pen at a two-day interval. The heart rate variability (HRV) and effort intensity, indicated as a percentage of maximum heart rate (%HRmax), were determined pre-lunging, during lunging at distinct gaits, and at 30-minute intervals for 120 minutes post-lunging. The correlation and method agreement between the two lunging methods were analysed with Pearson’s correlation coefficient and Bland–Altman plots, respectively. Results: The horses ran faster and covered longer distances during exercise on a lunge line than in a round pen. The effort intensity during cantering reached moderate levels (75.1 ± 2.4% HRmax) with occasional high-intensity levels (88.1 ± 1.3% HRmax) via both lunging methods. The HRV reached a minimum during cantering and returned to the baseline 120 minutes post-lunging. The HRV parameters (SDNN, RMSSD, LF, HF, SD1, and SD2) were strongly correlated ( r ≥ 0.97 and p < 0.001 for all) with a large correlation effect size (R > 0.85) and excellent agreement (average differences were within mean ± 1.96 SD) between the two lunging methods. Main limitations: The running speed and distance reported during lunging may not be entirely accurate due to the manual calculation required. Conclusions: Lunging can provoke optimal physiological responses in horses. The two tested lunging methods may be applied interchangeably for physical fitness training.

Application of the Ridden Horse Pain Ethogram to 150 Horses with Musculoskeletal Pain before and after Diagnostic Anaesthesia

Article

Full-text available

Jun 2023

Simple Summary Riders are often frustrated because when they recognise a decline in their horse’s performance, they seek professional advice and are informed that their horse is not lame based on an examination in hand ± on the lunge. The Ridden Horse Pain Ethogram (RHpE) was developed to facilitate the recognition of musculoskeletal pain in horses. An RHpE score of ≥8/24 reflects the likely presence of musculoskeletal pain. The aim of this study was to document observations made during ridden exercise of 150 horses with a history of poor performance, comparing RHpE scores before and after nerve blocks ± change of saddle. The most frequent lameness grade when ridden was 2/8 (range: 0–4); 35% of the horses had no overt lameness but lacked hindlimb impulsion. The most frequent RHpE score was 9/24 (range: 2–15/24), which declined to 2/24 (range: 0–12) after the interventions and was associated with improved gait quality and rideability. Despite recent professional saddle fit, an ill-fitting saddle contributed to poor performance in 37% of the horses. This study highlights the importance of ridden exercise in the investigation of poor performance/ low-grade lameness and the value of the RHpE to verify the presence of musculoskeletal pain. Nerve blocks are vital to determine the source(s) of pain that compromise performance. Abstract The Ridden Horse Pain Ethogram (RHpE) was developed to facilitate the recognition of musculoskeletal pain. The aim of this study was to document changes in RHpE scores before and after diagnostic anaesthesia was performed to alleviate pain ± when the saddle was changed. One hundred and fifty horses underwent ridden exercise as part of an investigation of poor performance. The RHpE was applied before and after the interventions. Fifty-two (34.7%) horses exhibited a bilaterally symmetrical short step length and/or restricted hindlimb impulsion and engagement. Fifty-three (35.3%) horses had episodic lameness; only forty-five (30.0%) horses were continuously lame. The median maximum lameness grade when ridden was 2/8 (interquartile range [IQR]: 0–3; range: 0–4). Fifty-six (37.3%) horses had an ill-fitting saddle, which was considered likely to influence performance. The median RHpE scores after the interventions (2/24 [IQR: 1–3, range: 0–12]) were significantly lower than before the interventions (9/24 [IQR: 8–11, range: 2–15]) (Wilcoxon signed-rank z = 10.6, p < 0.001). There was no correlation between the RHpE score and maximum lameness grade before diagnostic anaesthesia (Spearman’s rho = 0.09, p = 0.262). It was concluded that the absence of overt lameness does not preclude primary musculoskeletal pain. Gait quality and performance can be improved by diagnostic anaesthesia, with substantial reductions in RHpE scores.

Application of a Ridden Horse Pain Ethogram in Icelandic horses: A pilot study

Article

Full-text available

Apr 2023
EQUINE VET EDUC

Background A disturbing number of ridden horses are lame, although assumed by riders to be pain free. A Ridden Horse Pain Ethogram (RHpE) was developed; an RHpE score of ≥8/24 is likely to indicate the presence of musculoskeletal pain. Pain assessment in Icelandic horses is challenging; the RHpE may facilitate lameness recognition. Objectives To determine the repeatability of application of an adapted RHpE to Icelandic horses by a single observer. To evaluate the relationship between RHpE scores and lameness or abnormalities of canter. Study design Prospective, cross‐sectional study. Methods Video‐recordings of 30 Icelandic horses performing a standardised test (walk, trot, tölt, canter) were acquired. The adapted RHpE, to include tölt, was applied to all recordings twice in random order by a single observer. Agreement was assessed using Cohen's kappa. The presence of lameness, abnormalities of canter and lameness grade was determined by an independent expert. The association between maximum lameness grade and RHpE score was tested using Spearman's rank correlation. Results All horses exhibited both lameness, the majority in >1 limb, and abnormalities of canter. The RHpE score was ≥8/24 in 96% (median 10/24 and 10.5/24, respectively, for the two assessments). There was substantial to near‐perfect agreement for the majority of behaviours (63.6%) and moderate or fair agreement for 32%. There was no correlation between maximum lameness grades and RHpE scores. Main limitations The absence of non‐lame horses with correct saddle fit for horse and rider. Conclusions There was good repeatability of application of the RHpE. Musculoskeletal pain was associated with RHpE scores of ≥8/24 in the majority of horses. Data acquired from non‐lame horses, ridden in well‐fitting tack by riders of appropriate size, are needed to determine if the threshold of step frequency in trot needs to be adjusted for more accurate application of the RHpE in Icelandic horses.

Impact of Gait and Diameter during Circular Exercise on Front Hoof Area, Vertical Force, and Pressure in Mature Horses

Article

Full-text available

Dec 2021

Circular exercise can be used at varying gaits and diameters to exercise horses, with repeated use anecdotally relating to increased lameness. This work sought to characterize mean area, mean vertical force, and mean pressure of the front hooves while exercising in a straight line at the walk and trot, and small (10-m diameter) and large circles (15-m diameter) at the walk, trot, and canter. Nine mature horses wore TekscanTM Hoof Sensors on their forelimbs adhered with a glue-on shoe. Statistical analysis was performed in SAS 9.4 with fixed effects of leg, gait, and exercise type (PROC GLIMMIX) and p < 0.05 as significant. For all exercise types, the walk had greater mean pressure than the trot (p < 0.01). At the walk, the straight line had greater mean area loaded than the large circle (p = 0.01), and both circle sizes had lower mean vertical force than the straight line (p = 0.003). During circular exercise at the canter, the outside front limb had greater mean area loaded than at the walk and trot (p = 0.001). This study found that gait is an important factor when evaluating circular exercise and should be considered when exercising horses to prevent injury.

Application of a Ridden Horse Pain Ethogram to horses competing at 5‐star three‐day‐events: Comparison with performance

Article

Dec 2020
EQUINE VET EDUC

A Ridden Horse Pain Ethogram (RHpE) was previously developed to facilitate the detection of musculoskeletal pain. The objectives were to apply the RHpE during warm‐up for the dressage phase of two 5* three‐day events and to correlate the RHpE scores with subsequent performance. It was hypothesised that there would be a higher rate of failure to complete the cross‐country phase in horses which exhibited ≥7 behaviours compared with those showing <7 behaviours. The RHpE, comprising 24 behaviours, was applied for 10–12 min during warm‐up. Gait abnormalities in trot and canter were recorded. Dressage penalties, cross‐country performance, showjumping penalties and final placings were documented. Horses were categorised as those which completed cross‐country, or those which did not complete because of elimination or retirement. RHpE scores (n = 137) ranged from 0 to 9/24 (median 3 [range 0–9] for nonlame horses; median 5 [range 1–9] for horses with gait abnormalities in trot or canter). There was a moderate correlation between dressage penalty scores and the RHpE score (rho = 0.4, P<0.001, Spearman rank). Fifty‐nine per cent of horses (n = 10/17) with a RHpE score ≥7 failed to complete cross‐country, compared with 33% (n = 39/117) with a score <7. Horses that failed to complete the cross‐country phase had higher RHpE scores compared with those that completed (P = 0.04, W = 8.3, Kruskal–Wallis; pairwise comparison Bonferroni, P = 0.06). There was a significant (rho = 0.3) relationship between total RHpE score and final horse placings (n = 80, P<0.01, Spearman rank). Horses with lameness or gait abnormalities in canter had significantly higher RHpE scores (P<0.01, χ2 = 35, chi‐square test) compared with other horses. There was a strong correlation between the RHpE scores for horses which competed at both events (P<0.001, rho = 0.6, Spearman rank). The RHpE should facilitate earlier identification of horses which may benefit from diagnosis and treatment, resulting in improvement in both performance and equine welfare.

Can veterinarians reliably apply a whole horse ridden ethogram to differentiate nonlame and lame horses based on live horse assessment of behaviour?

Article

Jun 2020
EQUINE VET EDUC

A Ridden‐Horse‐Ethogram has been developed to differentiate between nonlame and lame horses, and lame horses before and after diagnostic analgesia has abolished musculoskeletal pain, based on video recordings. The objective of this prospective, observational study was to compare real‐time application of the Ridden‐Horse‐Ethogram with analysis of video recordings of the horses by a trained assessor and to determine whether veterinarians, after preliminary training, could apply the ethogram in real time in a consistent way and in agreement with an experienced assessor. Ten equine veterinarians (after preliminary training) and an experienced assessor applied the ethogram to 20 horse‐rider combinations performing a purpose‐designed dressage test (8.5 min). The horses were a convenience sample, in regular work, and capable of working ‘on the bit’. Video recordings of the test were analysed retrospectively by the experienced assessor. Lameness or abnormalities of canter, saddle fit, the presence of epaxial muscle tension/pain and rider skill level were determined by independent experts. The results were that 16 horses were lame; 11 had an ill‐fitting saddle; 14 had epaxial muscle tension/pain. The expert determined total scores of 3‐6/24 for the nonlame horses; two lame horses scored 3 and 6; 14 lame horses scored 8–16. There was no significant difference in real‐time scores and video‐based scores for the experienced assessor. There was good agreement between the expert's scores and the mean test observer scores. There was excellent consistency in overall agreement among raters (Intraclass correlation 0.97, P<0.001). There was a significant difference between ethogram scores according to lameness status for real‐time (P = 0.017) and video (P = 0.013) observations by the experienced assessor and for the test observers’ mean (P = 0.03). There was no effect of muscle pain, saddle fit or rider skill on behaviour. It was concluded that the ethogram was applied consistently by veterinarians with differentiation between nonlame and most lame horses. After appropriate training in its application, the ethogram may provide a useful tool for determining the presence of musculoskeletal pain in horses performing poorly.

Convolutional neural network for early detection of lameness and irregularity in horses using an IMU sensor

Preprint

Full-text available

Mar 2025

Lameness and gait irregularities are significant concerns in equine health management, affecting performance, welfare, and economic value. Traditional observational methods rely on subjective expert assessments, which can lead to inconsistencies in detecting subtle or early-stage lameness. While AI-based approaches have emerged, many require multiple sensors, force plates, or video systems, making them costly and impractical for field deployment. In this applied research study, we present a stride-level classification system that utilizes a single inertial measurement unit (IMU) and a one-dimensional convolutional neural network (1D CNN) to objectively differentiate between sound and lame horses, with a primary focus on the trot gait. The proposed system was tested under real-world conditions, achieving a 90% session-level accuracy with no false positives, demonstrating its robustness for practical applications. By employing a single, non-intrusive, and readily available sensor, our approach significantly reduces the complexity and cost of hardware requirements while maintaining high classification performance. These results highlight the potential of our CNN-based method as a field-tested, scalable solution for automated lameness detection. By enabling early diagnosis, this system offers a valuable tool for preventing minor gait irregularities from developing into severe conditions, ultimately contributing to improved equine welfare and performance in veterinary and equestrian practice.

The Equine Quality of Movement Score: How reliable is it?

Article

Full-text available

Mar 2025

Visually assessing equine quality of movement in the field is a routine part of performance management and rehabilitation procedures. To improve this subjective process, an outcome measure to grade quality of movement has been developed. The Equine Quality of Movement Score (EQoMS) is a battery of 30 standardised in-hand movement tests with a paired word and number grading system and directives to guide scoring based on key features. Six assessors (3 equine physiotherapists and 3 specialist equine veterinarians) scored video footage of 20 horses performing these movement tests. Videos were presented for scoring in a randomised order over two rounds with a 2-week gap in between. Intra-rater reliability was excellent (Spearman’s rho = 0.95, P = <0.001), and inter-rater reliability using ranked scores was moderately strong (Spearman’s rho = 0.66-0.95, P = <0.001). Assessors agreed on the relative quality of movement but disagreed on the absolute magnitude of movement quality. The assessors' free-text comments indicated a bias towards making negative comments. Reflecting the EQoMS directives, different features were commented on for different gaits, figures of movement and surfaces. Differences in terminology were found in the comments made by specialist equine veterinarians and equine physiotherapists, with the latter avoiding directly commenting on lameness. The variation in scores and comments emphasises the subjective nature of movement quality. Even when given the same training and directives to guide scoring, individual assessors' weighting of qualitative and quantitative elements was different. Further refinement is required to improve agreement on characteristics of equine movement, and the reliability of the EQoMS. Keywords: Equine physiotherapy, gait, movement dysfunction, outcome measure, rehabilitation.

Prevalence of movement asymmetries in high-performing riding horses perceived as free from lameness and riders’ perception of horse sidedness

Article

Full-text available

Jul 2024
PLOS ONE

A high proportion of horses in training, perceived as free from lameness by their owner, exhibit vertical movement asymmetries. These types of asymmetries are sensitive measures of lameness, but their specificity as indicators of orthopaedic pathology or locomotor function remains unclear. Equine athletes performing at a high level could be assumed to exhibit a higher degree of movement symmetry compared with the general horse population, but this has not been confirmed. This study investigated the prevalence of movement asymmetries in horses performing at a high level in three equestrian disciplines; show jumping, dressage and eventing, as well as the association between riders’ perception of horse sidedness and said movement asymmetries. Using an inertial measurement unit-based system (Equinosis), gait analysis was performed on 123 high-performing horses. The mean difference between the two vertical minimum and between the two maximum values of each stride was recorded for the head (HDmin, HDmax) and pelvis (PDmin, PDmax). The horses were defined as asymmetric if one or multiple asymmetry parameters exceeded an absolute trial mean of: >6mm for HDmin or HDmax, and >3mm for PDmin or PDmax, with standard deviation less than the respective mean value. Based on the results, 70% of the horses were classified as asymmetric, which is similar to previous findings for young riding horses and horses competing at a lower level. More than one-third of these high-performing horses had asymmetry values of similar magnitude to those seen in clinically lame horses. No clear associations were observed between rider-perceived sidedness and the vertical movement asymmetry values, indicating that the perceived unevenness between sides is not a determinant of vertical movement asymmetry. Longitudinal studies on movement asymmetries in relation to training intensity and full clinical examinations with local or systemic analgesic testing are desired as further research to determine whether these movement asymmetries indicate a welfare problem.

Advances in the Clinical Diagnostics to Equine Back Pain: A Review of Imaging and Functional Modalities

Article

Full-text available

Feb 2024

Simple Summary Back pain in horses is a common occurrence and has been considered to be an important factor affecting the well-being of horses. Its occurrence may be related to soft-tissue lesions, osseous injuries, tack-associated problems, or neurological disorders. In addition to conventional diagnostic methods, there are also more sophisticated ones, such as scintigraphy or computed tomography. Advanced diagnostic modalities include algometers, determination of lameness with inertial sensor systems, biometric mats, and geometric morphometrics methods, electromyography, as well as functional electrical stimulation. The purpose of this review article is to summarize the main back diseases in horses, as well as to provide an overview of their traditional, but also modern diagnostic methods. Although traditional diagnostic methods remain the foundation of orthopedic examination and back diseases, the use of new methods will allow for a better understanding of the pathogenesis of these diseases and will also allow for the objective monitoring of the rehabilitation and training process. Abstract Back pain is common in ridden horses. Back diseases in horses include Impinging Dorsal Spinous Processes, Ventral Spondylosis, Osteoarthritis of Articular Process, Intervertebral Discs Disease, Vertebral Fractures, Conformational Abnormalities, Desmopathy of the Supraspinous Ligament, Desmopathy of the Intraspinous Ligament, and Longissimus Muscle Strain. Back pain may also develop as a result of lameness (particularly hindlimb lameness). A poorly fitting saddle and an unbalanced rider are also considered important factors influencing the development of back pain in horses. The conventional diagnosis of equine back pain includes a clinical examination and diagnostic imaging examination using ultrasound, radiography, and thermography. Advanced diagnostic modalities of equine back pain involve the objectification of standard procedures through the use of algometers, a lameness locator, biometric mats, and the geometric morphometrics method. In addition to modern diagnostic methods, such as computed tomography and scintigraphy, advances in the diagnosis of equine back pain include the use of electromyography and functional electrical stimulation. The aim of this review article is to familiarize clinicians with the usefulness and capabilities of conventional diagnostic protocols and advanced diagnostic modalities. Although orthopedic examination and traditional diagnostic methods will remain the foundation of the diagnosis of back diseases, modern methods meet the growing expectations towards high-performance horses and allow for deeper diagnostics and objective monitoring of rehabilitation and training progress.

Objektive Messverfahren zur Bestimmung von Reitbodeneigenschaften und deren Einfluss auf den Bewegungsapparat des Pferdes – Ein Überblick

Article

Full-text available

Dec 2023
WIEN TIERARZTL MONAT

Zusammenfassung In dieser Arbeit wird ein Überblick über die Methoden zur Messung von Reitbodeneigenschaften, sowie zu den bisher bekannten Einflüssen dieser Eigenschaften auf den Bewegungsapparat des Pferdes gegeben. Der Fokus liegt auf Messmethoden für mechanische Eigenschaften, welche sehr vielfältig sind und von einfachen, unidirektional messenden bis hin zu komplexen Apparaten reichen, die versuchen, den Bewegungsablauf des Pferdes möglichst genau nachzuahmen. Außerdem gibt es Geräte, die in vivo die mechanische Interaktion zwischen Gliedmaße und Boden direkt messen. Eine Kombination verschiedener Methoden, sowie das Einbeziehen anderer Bodeneigenschaften und äußerer Einflüsse ist sinnvoll, um aussagekräftigere und vergleichbarere Schlüsse über Böden und deren Auswirkung auf Pferde zu ziehen. Dazu gehören z.B. die Bodenzusammensetzung, Wetterdaten, Pflegemaßnahmen, aber auch epidemiologische Verletzungsdaten der Pferde oder Computersimulationen. Bis heute gibt es bei Pferdesportveranstaltungen kaum ein Reglement zu verwendeten Böden, jedoch werden deren Effekte auf Leistung und Sicherheit der Pferde mit fortschreitenden Untersuchungen immer offensichtlicher. Einige Faktoren wie z.B. die Bodenhärte, Scherfestigkeit oder Kraftreduktion beim Auffußen sind für ihre Relevanz diesbezüglich bekannt und in einer Vielzahl an Böden untersucht. Anhand solcher Daten gab es beispielsweise im Pferdesport bereits zahlreiche Anpassungen hin zu sichererem Bodenmaterial, eine Optimierung von Pflege und Management der Böden, sowie teilweise die Etablierung verpflichtender Bodentestungen. In jeder Reitsportdisziplin liegen andere Belastungsmuster, Risikofaktoren und Pathologien zugrunde und es besteht, insbesondere in Disziplinen abseits des Rennsportes, noch viel Raum für Forschung und weitere Optimierung der verwendeten Böden. Summary Objective Methods for Measuring Riding Surface Properties and their Influence on the Musculoskeletal System of the Horse – Review This paper presents an overview of the methods for measuring riding surface properties, as well as the known influences of these properties on the musculoskeletal system of the horse. The focus is on methods for measuring mechanical properties. They are very diverse and range from simple, unidirectional methods to complex apparatuses that aim to mimic the horse's movement as closely as possible. There are also devices that measure the mechanical interaction between the limb and the ground directly in vivo. A combination of methods, and incorporating other surface properties and external influences, is useful in drawing meaningful and comparable conclusions about surfaces and their effects on horses. These include substrate composition, weather data and maintenance practices, as well as epidemiological equine injury data and computer simulations. There are still few regulations on surfaces used in equestrian events but their effects on horse performance and safety are becoming more apparent as research progresses. Factors such as hardness, shear strength and force reduction at footing are known to be relevant in this regard and have been studied in a variety of surface types. The data have led to numerous adaptations in equestrian sports, for example towards safer soil material, an optimization of the maintenance and management of the surfaces and the establishment of obligatory soil testing, which varies from region to region. In each equestrian discipline there are different underlying loading patterns, risk factors and pathologies and there is much room for research and further optimization of the surfaces used, especially in disciplines other than racing.

Reliability of surface electromyographic (sEMG) measures of equine axial and appendicular muscles during overground trot

Article

Full-text available

Jul 2023
PLOS ONE

The reliability of surface electromyography (sEMG) has not been adequately demonstrated in the equine literature and is an essential consideration as a methodology for application in clinical gait analysis. This observational study investigated within-session, intra-subject (stride-to-stride) and inter-subject reliability, and between-session reliability of normalised sEMG activity profiles, from triceps brachii (triceps), latissimus dorsi (latissimus), longissimus dorsi (longissimus), biceps femoris (biceps), superficial gluteal (gluteal) and semitendinosus muscles in n = 8 clinically non-lame horses during in-hand trot. sEMG sensors were bilaterally located on muscles to collect data during two test sessions (session 1 and 2) with a minimum 24-hour interval. Raw sEMG signals from ten trot strides per horse and session were DC-offset removed, high-pass filtered (40 Hz), full-wave rectified, and low-pass filtered (25 Hz). Signals were normalised to peak amplitude and percent stride before calculating intra- and inter-subject ensemble average sEMG profiles across strides for each muscle and session. sEMG profiles were assessed using waveform similarity statistics: the coefficient of variation (CV) to assess intra- and inter-subject reliability and the adjusted coefficient of multiple correlation (CMC) to evaluate between-session reliability. Across muscles, CV data revealed that intra-horse sEMG profiles within- and between-sessions were comparatively more reliable than inter-horse profiles. Bilateral gluteal, semitendinosus, triceps and longissimus (at T14 and L1) and right biceps showed excellent between-session reliability with group-averaged CMCs > 0.90 (range 0.90–0.97). Bilateral latissimus and left biceps showed good between-session reliability with group-averaged CMCs > 0.75 (range 0.78–0.88). sEMG profiles can reliably describe fundamental muscle activity patterns for selected equine muscles within a test session for individual horses (intra-subject). However, these profiles are more variable across horses (inter-subject) and between sessions (between-session reliability), suggesting that it is reasonable to use sEMG to objectively monitor the intra-individual activity of these muscles across multiple gait evaluation sessions at in-hand trot.

Poor Association between Facial Expression and Mild Lameness in Thoroughbred Trot-Up Examinations

Article

Full-text available

May 2023

Simple Summary Fatal injuries in Thoroughbred racehorses typically occur due to an accumulation of bone damage, however, detecting their impending onset can be difficult as there are often no overt signs. In other horse populations, facial grimacing has been shown to be associated with orthopaedic pain. This study, therefore, aimed to investigate facial expressions of Thoroughbred racehorses at the trot to identify if there were subtle signs of pain in mildly lame compared to non-lame horses. Two independent observers assessed 22 facial expression parameters using still photographs of the head from video-recorded trot-ups. There were few expressions associated with lameness except for more exposed whites of the eye in lame horses. Thus, facial pain scoring may not be adequate for the detection of subtle lameness in racehorses who work in a racing stable environment. Abstract Musculoskeletal injuries in racehorses are difficult to detect prior to catastrophic breakdown. Lameness is commonly attributed to orthopaedic pain in horses, therefore, subtle lameness may be a pre-clinical sign of injury and, if identified early, could allow for preventative intervention. Our objective was to determine if facial expressions could be used to detect mild lameness as an indicator of orthopaedic pain in ‘fit to race’ horses. The Horse Grimace Scale (HGS) and the facial expressions in ridden horses (FEReq), were used to score images (n = 380) of mildly lame (n = 21) and non-lame (n = 17) Thoroughbred horses by two independent observers. Using an Equinosis Lameness Locator®, the lameness status of each horse was determined according to published thresholds [forelimb lameness (>|14.5 mm|) and hindlimb lameness (>|7.5 mm|)]. Inter and intraobserver reliability were assessed using two-way random-effects models. Univariable associations between lameness and facial expression parameters were identified using logistic and linear regression. Interobserver reliability was moderate (κ 0.45; 95% CI 0.36, 0.55). Horses with moderate mouth strain (HGS) and tense and extended upper lip (FEReq) were less likely to be lame (p = 0.042 and p = 0.027, respectively). Exposed sclera was associated with lameness (p = 0.045). Higher orbital tightening (HGS) scores were associated with a lower degree of maximum head amplitude (HDmax) lameness (p = 0.044). Tension and moderate tension above the eye, for the HGS and FEReq scores, were associated with increasing amplitude of HDmax (p = 0.048 and p = 0.034, respectively). Inconsistent associations between lameness status and HGS and FEReq scores may limit the potential use of the facial expression for the prediction of mild orthopaedic pain during pre-race lameness examinations. More objective parameters associated with mild orthopaedic pain should be explored.

Circle Diameter Impacts Stride Frequency and Forelimb Stance Duration at Various Gaits in Horses

Article

Full-text available

Apr 2023
SENSORS-BASEL

The effects of gait and diameter have been studied independently, but rarely together in equine circular exercise studies. This study aimed to determine the impact of diameter (10-m or 15-m) at various gaits (walk, trot, and canter) on stride frequency or forelimb stance duration. Nine mature horses were outfitted with Tekscan™ Hoof Sensors on their forelimbs during circular and straight-line exercise at various gaits on a clay and sand arena surface. Statistical analysis was performed in SAS 9.4 with fixed effects of exercise type, recording, leg, and breed (PROC GLIMMIX, p < 0.05 significance). At walk (p < 0.0001) and trot (p < 0.001), stride frequency was lower during circular exercise. Stride frequency was similar between forelimbs at all gaits. At walk (p < 0.001) and canter (p = 0.01), stance duration was greatest during 10-m circle exercise. At walk (p = 0.0007), trot (p < 0.001), and canter (p < 0.0001), the inside forelimb had longer stance duration than the outside forelimb. Differences between forelimb stance durations may support asymmetrical travel while horses exercise on a circle at the walk, trot, and canter. These results demonstrate diameter and gait are important factors when evaluating forelimb kinematics during circular exercise.

Relative heights of the withers and the tubera sacrale and angulation of the lumbar and pelvic regions in horses with hindlimb proximal suspensory desmopathy, sacroiliac joint region pain and other orthopaedic injuries

Article

Oct 2022
EQUINE VET EDUC

Background In non‐lame horses, the tubera sacrale (TS) are usually lower than or, less commonly, equal in height to the withers. Thoracolumbosacral, pelvic and hindlimb posture/conformation may be influenced by musculoskeletal pain, and development and function of epaxial, pelvic and abdominal muscles. Objectives To investigate relationships between (1) conformation of the withers and pelvis and orthopaedic injuries; (2) tarsal angles and relative heights of the withers and TS. Study design Retrospective cross‐sectional clinical study. Methods Horses ( n = 193) presented for lameness or poor performance with a conclusive diagnosis based on abolition of clinical signs by diagnostic anaesthesia and imaging were included. Polystyrene hemispheres were adhered to the withers, TS and tubera ischiadica (TI). Lateral photographs were acquired with each horse standing squarely, with the head and neck in a neutral position, the metatarsal regions vertical, aligned with the TI. Relative heights of the withers and TS were determined using ImageJ. A line from the TS to the TI relative to the horizontal defined the pelvic angle. A line from the TS tangential to the lumbar region relative to the horizontal defined the lumbar angle. Measurements were compared across four injury groups consisting of hindlimb proximal suspensory desmopathy, primary sacroiliac joint region pain, a combination of both, and other causes of lameness. Results The withers height was ≥TS in 138/193 (71.5%) horses; the withers were lower than the TS in 55/193 (28.5%) horses. Pelvic and lumbar angles ranged from 20.0–42.7° (mean 28.9°, SD 3.4°) and 6.3–18.7° (mean 12.2°, SD 2.3°), respectively. No association between measurements and injury groups was determined. Main limitations There was a lack of non‐lame control horses. It was not possible to differentiate between innate conformation versus acquired posture. Conclusions Withers height was <TS in a larger proportion of lame horses compared with published data for non‐lame horses.

Evaluation of feedback methods for improved detection of hindlimb lameness in horses among riding instructors and trainers

Article

Full-text available

Oct 2022

Lameness, a wellknown issue in sport horses, impedes performance and impairs welfare. Early detection of lameness is essential for horses to receive needed treatment, but detection of hindlimb lameness is challenging. Riding instructors and trainers observe horses in motion in their daily work and could contribute to more efficient lameness detection. In this cross-sectional and prospective study, we evaluated the ability of riding instructors and trainers to assess hindlimb lameness. We also evaluated different feedback methods for improved lameness detection. For the cross-sectional part, n = 64 riding instructors and trainers of varying level and n = 23 high-level trainers were shown 13 videos of trotting horses, lameness degree: 0–3.5 (test 1) and tasked with classifying the horses as sound, left hindlimb lame, or right hindlimb lame. For the prospective part, the riding instructors and trainers of varying levels were randomly allocated to three different groups (a, b, c) and given 14 days of feedback-based, computer-aided training in identifying hindlimb lameness, where they assessed 13 videos (of which three were repeated from test 1) of horses trotting in a straight line. Participants in groups a-c received different feedback after each video (group a: correct answer and re-viewing of video at full and 65% speed; group b: correct answer, re-viewing of video at full and 65% speed, narrator providing explanations; group c: correct answer and re-viewing of video at full speed). After computer-aided training, the participants were again subjected to the video test (test 2). Participants also provided background information regarding level of training etcetera. Effects of participants' background on results were analyzed using analysis of variance, and effects of the different feedback methods were analyzed using generalized estimation equations. On test 1, 44% (group a), 48% (b), 46% (c), and 47% (high-level trainers) of horses were correctly classified. Group a participants significantly improved their test score, both with (p < 0.0001) and without (p = 0.0086) inclusion of repeated videos. For group c, significant improvement was only seen with inclusion of repeated videos (p = 0.041). For group b, no significant improvement was seen (p = 0.51). Although test 2 scores were low, computer-aided training may be useful for improving hindlimb lameness detection.

Welfare Concerns for Mounted Load Carrying by Working Donkeys in Pakistan

Article

Full-text available

May 2022

Working donkeys (Equus asinus) are vital to people's livelihoods. They are essential for carrying goods, however, globally, overloading is one of the primary welfare concerns for working donkeys. We studied mounted load carrying by donkeys and associated factors in Pakistan. A cross-sectional study of donkey owners (n = 332) was conducted, and interviews were undertaken based on a questionnaire. Owners estimated that the median weight of their donkeys was 110 kg [interquartile range (IQR) 100–120 kg], and that they carried a median mounted load of 81.5 kg (IQR 63–99 kg). We found that 87.4% of donkeys carried a load above 50% of their bodyweight ratio (BWR), the median BWR carried was 77.1% (IQR 54.5–90.7%), and 25.3% of donkeys carried above 90% BWR. Donkeys that were loaded at more than 50% BWR were more likely to adopt sternal recumbency compared to donkeys loaded with less weight (P = 0.01). Donkeys carrying construction material were more likely to carry more than the median BWR, when compared to domestic loads (P < 0.001). Younger donkeys aged between one and 5 years carried more than the median BWR compared to those aged over 15 years (P = 0.03). For the models with donkeys carrying median BWR and above 90% BWR, those working in peri-urban and urban areas were more likely to carry a greater BWR than donkeys working in rural areas (P < 0.001; P < 0.001, respectively). For donkeys carrying more than 90% BWR, mixed breed donkeys carried higher loads compared to other breeds of donkeys (P < 0.001). Overloading based on current recommendations (50% BWR) was common, with the majority (87.4%) of donkeys reported to carry more than the recommended 50% limit. This survey provides evidence of on-the-ground working practices and factors associated with mounted load carrying, which is critical for developing evidence-based recommendations for loading, in order to improve the welfare of working donkeys.

Cross-Sectional Questionnaire of Donkey Owners and Farriers Regarding Farriery Practices in the Faisalabad Region of Pakistan

Article

Full-text available

Mar 2022

Quality farriery is essential to ensure donkey welfare, and many intervention programs in low-middle income countries (LMICs) train farriers, and educate owners, regarding the farriery needs of donkeys. It is essential for interventional programs to understand the perspectives of all stakeholders in donkey-owning communities. A cross-sectional questionnaire study was conducted in the Faisalabad region of Pakistan. Ten farriers and 55 donkey owners participated in the study. Farriers reported receiving no formal training for farriery, insufficient wages (PKR 65 or USD 0.36 per hoof) and the requirement to use traditional tools. Farriers reported an average shoeing time of 5 min per hoof and shoeing between three and 30 donkeys a day. Donkeys were mostly shod while they were harnessed to a cart. Six donkey-owning farriers reported shoeing their donkeys every 20 to 25 days. Owners reported varying shoeing intervals of 20 days to 90 days. Shoeing interval was also affected by seasonal and weather changes. Owners considered their relationship with farriers as the most important factor in choosing a farrier rather than cost. A majority (87%) of the owners reported lameness in their donkeys. The study provides important insights into the many challenges and opportunities in developing quality donkey farriery in the region.

Welfare concerns for mounted load carrying by working donkeys in Pakistan

Preprint

Full-text available

Mar 2022

Working donkeys (Equus asinus) are vital to peoples livelihoods. They are essential for carrying goods, however globally, overloading is one of the primary welfare concerns of working donkeys. We studied mounted load carrying by donkeys and associated factors in Pakistan. A cross-sectional study of donkey owners (n = 332) was conducted, and interviews were undertaken based on a questionnaire. Owners estimated that the median weight of their donkeys was 110kg (interquartile range (IQR) 100-120kg), and that they carried a median mounted load of 81.5kg (IQR 63-99kg). We found that 87.4% of donkeys carried a load above 50% of their bodyweight ratio (BWR), the median BWR carried was 77.1% (IQR 54.5-90.7%), and 25.3% of donkeys carried above 90% BWR. Donkeys that were loaded at more than 50% BWR were more likely to sit, compared to donkeys loaded with less weight (p=0.01). Donkeys working in peri-urban and urban areas were more likely to carry a greater BWR than donkeys working in rural areas (P<0.001), as were those carrying construction materials or bricks, compared to agricultural materials (p=0.004). Age (p=0.03) and breed (p=0.01) were also associated with carrying a higher weight. Overloading based on current recommendations (50% BWR) was common, with the majority (87.4%) of donkeys reported to carry more than the recommended 50% limit. This survey provides evidence of on-the-ground working practices and factors associated with mounted load carrying, which is critical for developing evidence-based recommendations for loading, in order to improve the welfare of working donkeys.

Application of the Ridden Horse Pain Ethogram to Horses Competing in British Eventing 90, 100 and Novice One-Day Events and Comparison with Performance

Article

Full-text available

Feb 2022

The Ridden Horse Pain Ethogram (RHpE) was applied to 1010 competition starts at British Eventing (BE) 90, 100 and Novice one-day events and compared with performance. The overall median RHpE score was 4/24 (IQR 2,6; range 0,12). There were moderate positive correlations between RHpE scores and dressage penalties (Spearman’s rho = 0.508, 0.468, 0.491, all p < 0.001 for BE 90, 100 and Novice, respectively). There were weak positive correlations between RHpE scores and final placings (Spearman’s rho = 0.157, p = 0.033, BE90; rho = 0.263, p < 0.001, BE 100; rho = 0.123, p = 0.035, Novice). In showjumping, 1.7% of starters were eliminated or retired, compared with 9.8% of cross-country starters. Horse or rider falls occurred in 2.6% of cross-country starts. Horses placed first, second or third had lower median RHpE scores (2/24, IQR 1,4; range 0,8) than other horses that finished (p < 0.001), those that were eliminated or retired (p < 0.001) or were withdrawn (p < 0.001). The RHpE score was ≥8/24 for 9.3% of starters; horses with a RHpE score ≥8/24 had higher total penalty scores (p < 0.001) than horses with a RHpE score <8/24. The overall low median RHpE score supports the social licence to compete, but 9% of starters had a RHpE score ≥8/24. Investigation and treatment of these horses may improve both welfare and performance.

Do owners recognise abnormal equine behaviour when tacking‐up and mounting? A comparison between responses to a questionnaire and real‐time observations

Article

Mar 2021
EQUINE VET EDUC

Background Causes of abnormal behaviour during tacking‐up or mounting are multifactorial, but may be associated with an ill‐fitting saddle, a rider sitting on the caudal third of the saddle, or lameness. Objectives To determine whether: (1) owners believed their horse showed abnormal behaviour when tacked‐up or mounted; (2) this agreed with observations by a veterinarian. Study design Cross‐sectional study; convenience sample. Methods Horses were undergoing prepurchase examinations, investigation of poor performance, or were recruited by invitation. Owners were asked if their horse showed abnormal behaviour when tacked‐up or mounted and subsequently whether they showed specific behaviours (yes/no) during bridling, saddling, girthing and mounting. Each horse was observed during tacking‐up and mounting by one veterinarian who recorded the occurrence of each behaviour. Agreement between the owners and the veterinarian was evaluated using intraclass correlation (ICC) coefficients with 95% confidence intervals (CI). Results Overall 34.2% (66/193) of owners reported that their horse showed behavioural abnormalities during tacking‐up or mounting. There was poor to good agreement between the owners and veterinarian for horses putting their head up to avoid bridling (ICC 0.53, CI 0.37, 0.64) and being reluctant to open their mouth for the bit (ICC 0.52, CI 0.36, 0.64). There was poor to fair agreement for evading noseband tightening (ICC 0.41, CI 0.21, 0.56), elevating the head (ICC 0.24, CI 0.00, 0.43) and teeth grinding (ICC 0.23, CI 0.00, 0.42). For attempts to bite, there was fair to excellent agreement during saddling (ICC 0.67, CI 0.56, 0.75) and good to excellent agreement during girthing (ICC 0.73, CI 0.64, 0.79). Results for some behaviours suggested potential systematic disagreement between the veterinarian and owners. Main limitations Potential bias of volunteers recruited by invitation. Day‐to‐day variation of behaviours is unknown. Conclusions The majority of owners were unaware that their horses showed behavioural abnormalities during tacking‐up or mounting.

The Ridden Horse Pain Ethogram

Article

Mar 2021
EQUINE VET EDUC

Sue Dyson

The Ridden Horse Pain Ethogram (RHpE) comprises 24 behaviours, the majority of which are at least 10 times more likely to be seen in lame horses compared with non‐lame horses. The observation of ≥8/24 behaviours is likely to reflect the presence of musculoskeletal pain, although some lame horses score <8/24 behaviours. A marked reduction in RHpE scores after resolution of lameness using diagnostic anaesthesia proves a causal relationship between pain and RHpE scores. Horses should be assessed for approximately 10 min in walk, trot (including 10 m diameter circles), canter and transitions. The validity of the RHpE has been verified for use in horses which perform dressage‐type movements, and which have been trained to work with the front of the head in a vertical position. It has not, as yet, been used in horses while jumping, racehorses, western performance or endurance horses. The RHpE provides a valuable tool for riders, trainers, veterinarians and other equine professionals to recognise the presence of musculoskeletal pain, even if overt lameness cannot be recognised. Riders with a higher skill‐level may improve gait quality, but cannot obscure behavioural signs of pain, although specific behaviours may change. Tight saddle tree points, the rider sitting on the caudal third of the saddle and rider weight may influence RHpE scores. Accurate application of the RHpE requires training and practice. The RHpE is a powerful tool for the assessment of ridden horses and the identification of likely musculoskeletal pain. Such pain merits further investigation and treatment, to improve equine welfare and performance. The RHpE provides an additional means of evaluating the response to diagnostic anaesthesia. It provides a mechanism for client education and a diplomatic way of communicating with clients about equine discomfort related to saddle‐fit, rider size, their position in the saddle and ability to ride in balance.

An investigation of behaviour during tacking‐up and mounting in ridden sports and leisure horses

Article

Jan 2021
EQUINE VET EDUC

Background There has been no large‐scale, evidence‐based study on horses’ behaviour while being tacked ‐up or mounted. Objectives To describe equine behaviour during tacking‐up and mounting. Study design Cross‐sectional, prospective observational study, using a convenience sample. Methods A purpose‐designed protocol for documenting behaviour during tacking‐up and mounting was developed. Horses were recruited from 11 locations, from both amateur and professional riders. Horses (n = 193) were observed during acquisition of predefined information from the owners. Behaviour data were recorded during bridling, placement of the saddle, girthing and mounting. Results The majority (67%) were bridled first. The median sum of abnormal behaviours during tacking‐up was 10/64 (interquartile range [IQR] 7.13; range 0.33). There was an equal frequency of abnormal behaviours during bridling and saddling in 52% of horses; 34% of horses showed more abnormal behaviours during saddling than bridling; 15% of horses showed more abnormal behaviours during bridling than saddling. The duration of abnormal behaviours related to total tacking‐up time was 25–75% in 51% of horses. There was a positive relationship between the sum of abnormal behaviours and the duration of abnormal behaviours (P = 0.0001). Repeatedly chomping on the bit occurred most frequently during bridling (67%). Ears back (57–65%) and an intense stare (54–62%) were similar in all phases. Fidgeting was more common during saddle placement (32%) and girthing (21%), than bridling (9%). Tail swishing was more frequent during saddle placement (20%) and girthing (34%), than bridling (10%). Turning the head to the girth was only seen during saddle placement and girthing (11 and 40%, respectively), in addition to attempting to bite (5 and 15%, respectively) and rubbing the nose (8 and 21%, respectively). The median sum of abnormal behaviours during mounting was 1/30 (IQR 1.3; range 0.12). Main limitations Absence of many nonlame horses with correctly fitting tack. Conclusion Abnormal behaviour during tacking‐up and mounting was common.

The influence of rider skill on ridden horse behaviour, assessed using the Ridden Horse Pain Ethogram, and gait quality

Article

Dec 2020
EQUINE VET EDUC

Background The Ridden Horse Pain Ethogram (RHpE) was developed to facilitate identification of musculoskeletal pain. Objectives To determine the influence of rider skill on ridden horse performance and behaviour, the latter using the RHpE. It was hypothesised that gait quality at trot and canter would improve with a more skilled rider compared with a less skilled rider, but the RHpE scores would be similar. Study design Repeated measures investigation. Methods Forty horses, in regular work and presumed by their riders to be nonlame, were ridden by their normal rider (N) and a skilled professional rider (P), performing a dressage‐type test over 8.5 min. Twenty horses were ridden first by rider P, and 20 were ridden first by rider N. The presence of lameness or gait abnormalities in canter was recorded. Standardised video recordings were acquired. All videos were anonymised and presented in random order to the assessors. Rider skill and horse gait quality were graded (Fédération Equestre Internationale scale, 1–10), and the RHpE was applied to each horse using the video recordings. Results Rider P had a higher median skill score (6/10) compared with the N riders (4.5/10) (P<0.001). There was a correlation between rider skill scores and gait quality scores (P<0.001). The presence of lameness or gait abnormalities in canter, when ridden by riders N and P, varied among horses. The median RHpE score for all horses was 9/24 (range 3–14). There was no difference in mean or median RHpE scores between the N riders and rider P. There was some variance in the frequency of occurrence of specific behaviours between the N riders and rider P. Main limitations The identity of rider P could not be concealed. Conclusions There was no direct relationship between rider skill level and the RHpE score, but riders did alter the manifestations of some behaviours.

Objectively measured movement asymmetry in yearling Standardbred trotters

Article

Full-text available

Jul 2020
EQUINE VET J

Background Lameness evaluation of Standardbred trotters can be challenging due to discrepancies in observed movement asymmetry between in‐hand and track exercise, and between different trotting speeds. There are few studies on objective measurement of movement in Standardbreds, and little knowledge regarding biological variation and clinical significance of measured movement asymmetry in this breed. Objectives To quantify the prevalence and magnitude of objectively measured movement asymmetry in young Standardbred trotters, and identify associations with trainer, sex, height, track type and in‐hand measurement prior to or after track trials. Study design Cross‐sectional, observational study. Methods A total of 114 Standardbred yearlings were evaluated with a wireless inertial sensor system during trot in‐hand and when driven on a track. After exclusions relating to lameness or technical difficulties, 103 horses were included in the study; 77 were evaluated in‐hand and on the track, 24 only in‐hand and 2 only on the track. Results Front and/or hindlimb parameters were above asymmetry thresholds previously established for other breeds during in‐hand trials for 94 (93%) horses and during track trials for 74 (94%) horses. Most horses showed mild asymmetry. A minority of horses (20%) switched side of the asymmetry for one or more parameters between in‐hand and track trials. Mixed model analyses revealed no significant effects of trial mode (in‐hand or track trial, in‐hand trial pre‐ or post‐track trial, straight or oval track), trainer or horse height. Females had a significant but small reduction in asymmetry in one front limb parameter (HDmax) compared with males (1.7 mm, 95% CI 0.18‐3.28, P = .03). Main limitations High data variability, reflected in large trial standard deviations, relating mainly to a lack of horse compliance. Conclusions A high proportion of Standardbred yearlings showed movement asymmetries. There was no group‐level effect between in‐hand and track trials, however, considerable individual variation was observed.

Application of a Ridden Horse Pain Ethogram and Its Relationship with Gait in a Convenience Sample of 60 Riding Horses

Article

Full-text available

Jun 2020

Simple Summary Horse owners are poor at recognising lameness which may compromise equine welfare. A Ridden Horse Pain Ethogram, comprising 24 behaviours with specific definitions, was developed to facilitate identification of musculoskeletal pain. Previous studies demonstrated that the presence of ≥8/24 behaviours is likely to reflect musculoskeletal pain. The aim of this study was to further test the Ridden Horse Pain Ethogram by applying it to a convenience sample (n = 60) of sports horses and riding school horses in regular work and assumed by their owners to be working comfortably. All horses performed a purpose-designed dressage-type test of 8.5 min duration in walk, trot and canter, with their normal rider. The presence of increased back muscle tension or pain, poor saddle fit, gait abnormalities and rider skill were assessed by independent experts. The Ridden Horse Pain Ethogram was applied retrospectively, by a trained analyst, to video recordings which had been acquired in a standardised fashion. There was a significant association between the Ridden Horse Pain Ethogram score and lameness. Lame horses had higher scores than non-lame horses. Education of riders about behaviours which may reflect pain in ridden horses could allow the earlier identification of lame horses, whose welfare may be improved by accurate diagnosis and treatment. Abstract A Ridden Horse Pain Ethogram (RHpE) comprising 24 behaviours has been developed to facilitate the identification of musculoskeletal pain. The aim was to further test the RHpE by its application to a convenience sample (n = 60) of sports horses and riding school horses in regular work and assumed by their owners to be working comfortably. All horses performed a purpose-designed dressage-type test of 8.5 min duration in walk, trot and canter, with their normal rider. The RHpE was applied retrospectively to video recordings acquired in a standardised fashion. Seventy-three percent of horses were lame (≤ grade 2/8) on one or more limbs; 47% had gait abnormalities in canter. Ridden Horse Pain Ethogram scores ranged from 3 to 16/24 (median 9); rider skill score ranged from 2.5 to 8/10 (median 4.75). The effect of horse age, breed, sex, work-discipline, epaxial muscle hypertonicity or pain, an ill-fitting saddle, rider skill score, the presence of lameness or gait abnormalities in canter on the RHpE score was assessed using Poisson regression. Two variables were retained in the final multivariable analysis, rider skill score as a continuous variable (p < 0.001), and lameness (p = 0.008). A RHpE score ≥8 was a good indicator of the presence of musculoskeletal pain.

Husbandry, Use, and Orthopedic Health of Horses Owned by Competitive and Leisure Riders in Switzerland

Article

Apr 2020
J EQUINE VET SCI

The use of horses in competitive sports receives increasing criticism from the public, mainly due to the potential for injury. However, it is unclear if orthopaedic and other health issues are more common in competition horses when compared to leisure horses. The aim of this study was to assess husbandry, use, and orthodpeadic health in Swiss riding horses, and to compare these aspects between horses owned by self-identified competitive (CR) and leisure riders (LR) in Switzerland. 237 owners completed an online survey providing information on their athletic ambitions, their horse’s husbandry, health, training, and tack. Two experienced veterinarians assessed gait irregularities, muscular development, and back pain in the horses, and evaluated saddle fit. Compared to horses owned by competitive riders (CH), a higher proportion of horses kept by leisure riders (LH) were kept unshod, under more natural conditions, and turned out with other horses. LH were exercised less frequently and LR trained less frequently with instructors. CR reported more frequent saddle checks and the use of more training aids during riding. No differences between the two groups could be found in orthopaedic health, muscular development, or back pain, but LH had higher BCSs and a slightly higher proportion of saddles with at least one fit problem. Our data revealed no increased prevalence of the assessed health problems in competition horses compared to leisure horses in Switzerland. However, suboptimal saddle fit and muscular development, back pain, and gait irregularity are frequent in both groups and deserve more attention.

Asymmetries of horses walking and trotting on treadmill with and without rider

Article

Full-text available

Apr 2020
EQUINE VET J

Background Left‐right movement symmetry is a highly desirable characteristic in sport horses. Objectives This study compared movement symmetry in well‐trained dressage horses in unridden and unrestrained position and ridden in a dressage frame, and investigated possible associations between gaits. Study design Experimental study. Methods Seven sound, high‐level dressage horses were measured at walk and sitting trot on a treadmill at several speeds under two conditions: with and without rider. Left‐right differences in stance duration, stance protraction and retraction based on longitudinal hoof positions, ipsilateral limb tracking, minimum and maximum vertical positions of the dorsal spinous processes of the sixth thoracic (T6), third sacral vertebrae (S3) and wing of atlas, and vertical ground reaction forces were calculated and analysed in mixed models. Results At walk, five body variables indicated increased asymmetry in the ridden condition compared with unridden condition: forelimb stance duration (unridden/ridden left‐right differences 9 vs 13 ms; P = .008), forelimb stance protraction (P = .004), stance retraction (P = .001) and first force peak (P = .003), and hindlimb stance retraction (P = .01). At trot, six body variables were more asymmetrical in the ridden condition: forelimb stance duration (2.5 vs 3.8 ms, P = .004); hindlimb stance protraction (P < .0001) and retraction (P = .01), T6 minimum (4 vs 6 mm, P = .001), T6 maximum (9 vs 11 mm, P = .01) and S3 maximum (6 vs 12 mm, P < .001). Five variables had significant associations between asymmetries at walk and trot, but only three demonstrated a positive slope. Main limitations A limited number of horses and riders were studied. Measurements were performed on a treadmill. Conclusions High‐level horses moved slightly more asymmetrically when ridden in a dressage frame than in the unridden condition.

Range of motion and between-measurement variation of spinal kinematics in sound horses at trot on the straight line and on the lunge

Article

Full-text available

Feb 2020
PLOS ONE

Clinical assessment of spinal motion in horses is part of many routine clinical exams but remains highly subjective. A prerequisite for the quantification of spinal motion is the assessment of the expected normal range of motion and variability of back kinematics. The aim of this study was to objectively quantify spinal kinematics and between -measurement, -surface and -day variation in owner-sound horses. In an observational study, twelve owner-sound horses were trotted 12 times on four different paths (hard/soft straight line, soft lunge left and right). Measurements were divided over three days, with five repetitions on day one and two, and two repetitions on day three (recheck) which occurred 28–55 days later. Optical motion capture was used to collect kinematic data. Elements of the outcome were: 1) Ranges of Motion (ROM) with confidence intervals per path and surface, 2) a variability model to calculate between-measurement variation and test the effect of time, surface and path, 3) intraclass correlation coefficients (ICC) to determine repeatability. ROM was lowest on the hard straight line. Cervical lateral bending was doubled on the left compared to the right lunge. Mean variation for the flexion-extension and lateral bending of the whole back were 0.8 and 1 degrees. Pelvic motion showed a variation of 1.0 (pitch), 0.7 (yaw) and 1.3 (roll) degrees. For these five parameters, a tendency for more variation on the hard surface and reduced variation with increased repetitions was observed. More variation was seen on the recheck (p<0.001). ICC values for pelvic rotations were between 0.76 and 0.93, for the whole back flexion-extension and lateral bending between 0.51 and 0.91. Between-horse variation was substantially higher than within-horse variation. In conclusion, ROM and variation in spinal biomechanics are horse-specific and small, necessitating individual analysis and making subjective and objective clinical assessment of spinal kinematics challenging.

Use of Physical Self-Experience for Teaching Lameness Evaluation: Short-Term Effects on Lameness Evaluation of Horses with Mild Forelimb Lameness by Novice Veterinary Students

Article

Nov 2019

Lameness evaluation (LE) is an important veterinary skill, but it can be a challenging task to teach. Acoustic and visual input in conjunction with acting are the three major learning channels for acquiring new information. Acting (e.g., physical self-experience) has not been reported as didactic tool for LE; therefore, we investigated two physical self-experience techniques, imitation of lameness during LE instruction and head nod during LE. Undergraduate veterinary students (N = 78) who had not yet received any instructions for LE underwent standard instruction for LE, followed by instructions to head nod, instructions to imitate lameness, or neither. Students' subjective LE skills were then tested against those of senior clinicians on two horses that were either sound or mildly forelimb lame. In more than 80%, there was agreement on the presence or absence of lameness independent of instruction, and we found no significant evaluation differences between didactic strategies. Specific instructions for head nodding did not significantly influence the quality of LE, possibly because head nodding was widespread even when no specific instructions had been given. Veterinary students who had been taught to imitate lameness without instructions to head nod were consistently closest to the assessment of the senior clinicians, and in walk these students were significantly better at LE than students additionally instructed to head nod. This finding indicates that imitation of lameness, but not necessarily head nodding, may be beneficial for understanding body movement such as mild equine forelimb lameness.

An investigation into the occurrence of, and risk factors for, concurrent suspensory ligament injuries in horses with hindlimb proximal suspensory desmopathy

Article

Oct 2019
EQUINE VET EDUC

Hindlimb proximal suspensory desmopathy (PSD) is a common cause of lameness or poor performance in horses and may occur alone or together with other suspensory ligament (SL) injuries in forelimbs or hindlimbs. The aims of this retrospective case‐control study (January 2009 to December 2018) were to describe the occurrence of, and identify risk factors for, concurrent SL injuries in horses with hindlimb PSD. Data concerning age, breed, sex, work discipline, height, bodyweight and work history were collected. Concurrent SL injuries were defined as forelimb proximal suspensory desmitis or SL branch injuries (≥grade 2 [0–3]) in any limb. Hindlimb PSD was graded mild, moderate or severe based on ultrasonography. Data were described, and multivariable logistic regression modelling was used to identify factors associated with concurrent SL injuries. Data were available for 923 horses with hindlimb PSD, 28.6% (n = 264) of which had concurrent SL injuries. Age category (≤5 years of age vs. ≥6 years of age; P = 0.008), bodyweight:height ratio (P = 0.001), breed (P = 0.05), symmetry vs. asymmetry of hindlimb PSD ultrasonography grade (P = 0.005) and asymmetry vs. symmetry of lameness grade (P = 0.02) were associated with concurrent SL injury in horses with hindlimb PSD. Compared with horses aged ≥ 6 years, younger horses (odds ratio [OR] 1.76; 95% confidence interval [CI] 1.2–2.7) were more likely to have concurrent SL injury. The risk for concurrent SL injuries increased for every unit increase in bodyweight:height ratio (OR 2.27; CI 1.4–3.7). Compared with Thoroughbred crosses, Warmblood crosses (OR 3.3, CI 1.4–7.8), Thoroughbreds (OR 2.9, CI 1.1–7.1) and Irish Draught Horses (OR 3.5, CI 1.3–9.9) were more likely to have concurrent SL injuries. Hindlimb PSD ultrasonography grade severity was not associated with concurrent SL injury. In conclusion, age, bodyweight:height ratio and breed influenced the risk for concurrent lesions of the SL ligament. Further prospective studies in young horses are warranted.

Range of motion and between-measurement variation of spinal kinematics in sound horses at trot on the straight line and on the lunge

Preprint

Full-text available

Sep 2019

Clinical assessment of spinal motion in horses is part of many routine clinical exams but remains highly subjective. A prerequisite for the quantification is the assessment of the expected normal range of motion and variability of back kinematics. The aim of this study was to objectively quantify spinal kinematics and between -measurement, -surface and -day variation in owner-sound horses. In an observational study, twelve owner-sound horses were trotted 12 times on four different paths (hard/soft straight line, soft lunge left and right). Measurements were divided over three days, with five repetitions on day one and two, and two repetitions on day three (recheck) which occurred 28-55 days later. Optical motion capture was used to collect kinematic data. Elements of the outcome were: 1) Ranges of Motion (ROM) with confidence intervals per path and surface, 2) a variability model to calculate between-measurement variation and test the effect of time, surface and path, 3) intraclass correlation coefficients (ICC) to determine repeatability. ROM was lowest on the hard straight line. Cervical lateral bending was doubled on the left compared to the right lunge. Mean variation for the flexion-extension and lateral bending of the whole back were 0.8 and 1 degrees. Pelvic motion showed a variation of 1.0 (pitch), 0.7 (yaw) and 1.3 (roll) degrees. For these five parameters, a tendency for more variation on the hard surface and reduced variation with increased repetitions was observed. More variation was seen on the recheck (p<0.001). ICC values for the pelvis were between 0.76 and 0.93, for the whole back flexion-extension and lateral bending between 0.51 and 0.91. Between-horse variation was substantially higher than within-horse variation. Concluding, ROM and variation in spinal biomechanics are horse-specific and small, necessitating individual analysis and making subjective clinical assessment of spinal kinematics challenging.

Effect of meloxicam treatment on movement asymmetry in riding horses in training

Article

Full-text available

Aug 2019
PLOS ONE

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?

Facial expressions and emotions in domestic animals. CABI, England (2019).

Article

Full-text available

May 2019

In many animal species, facial expressions are key elements for recognising emotions and numerous types of social interaction. Emotions are complex reactions that allow individuals to cope with full events that have either positive or negative meaning and involve certain neurophysiological responses proper to each emotion and species. Regulating emotional states requires integrating a whole series of responses –peripheral, autonomous, endocrine and muscular– that entail activating various sub-cortical structures, including the amygdale, hypothalamus and brainstem. In recent decades, interest in the emotions expressed by animals has grown, and researchers have come to understand that some problems of animal welfare can be detected by examining and comprehending the emotional experiences that animals may suffer, and identifying how they demonstrate their reactions through facial expressions and corporal postures. The objective of this review is to examine recent literature on aspects related to the function of the emotions and facial expressions in certain domestic species:–cats, dogs, rats, sheep, horses and pigs– and propose that understanding facial expressions can be useful as a complement to existing tools in assessing welfare and working with, or doing research on, these species.

The “misbehaving” performance horse: is it ever behavioral?

Article

Mar 2025
J EQUINE VET SCI

Erin K. Contino

ANIMAL WELFARE BOOK. Chapter 7. Facial expressions and emotions in domestic animals / Expresiones faciales y emociones en animales domésticos. 4th edition. (2024): 247-276. ISBN 978-607-99008-3-0

Chapter

Full-text available

Dec 2024

Intérêt de l’examen du cheval monté et de l’analyse du geste sportif

Article

Nov 2024

L’observation du cheval monté et l’analyse du geste sportif donnent souvent des informations pertinentes complémentaires à l’examen locomoteur conventionnel en main. Celui-ci est toujours réalisé avant, afin d’exclure toute lésion qui pourrait s’aggraver lorsque le cheval est monté. La demande d’analyse du geste sportif est fréquente chez les cavaliers de haut niveau, mais elle a également un intérêt chez les chevaux de sport de niveau inférieur, car plusieurs études ont démontré qu’un pourcentage non négligeable de douleurs musculosquelettiques ne sont visibles que lorsque le cheval est monté. Lors du travail sur le plat et en dressage, les gênes peuvent devenir visibles lors du travail sur 2 ou 3 pistes, dans les transitions, sur les courbes serrées, lors du rassembler ou dans les changements de direction. À l’obstacle, les anomalies du geste peuvent apparaître lors de la foulée de battue, du planer et de la réception, ou en parcours lors de combinaisons et de tournants. L’effet des anesthésies diagnostiques distales sur le geste sportif peut être évalué, mais seulement après un bilan d’imagerie préalable. Enfin, des grilles d’expression de douleur chez le cheval monté ont été élaborées par des chercheurs ; elles aident à différencier les signes de douleur des problèmes comportementaux ou induits par le cavalier.

Physiological responses and agreement between two traditional lunging protocols for physical fitness training in untrained ponies

Article

Oct 2024
J EQUINE VET SCI

Horse Owners' Knowledge of Fundamental Care and their Perceptions on the Implementation of a Mandatory Certificate of Knowledge

Article

Aug 2024
J APPL ANIM WELF SCI

Visually Assessing Equine Quality of Movement: A Survey to Identify Key Movements and Patient-Specific Measures

Article

Full-text available

Sep 2023

Simple Summary Physiotherapy and rehabilitation is a burgeoning area of practice; to be evidence-based, it needs outcome measures designed for its focus on function. Based on frequency of use and rationale, this online survey aimed to identify a core group of in-hand assessments for equine movement. Additionally, the survey gathered information on how movement is currently monitored and opinions on the usefulness of modifying a patient-reported outcome measure for equine use. The survey attracted 81 participants and identified 24 key movements, including walk and trot on both firm and soft surfaces in a straight line and on a small circle, plus step back, hind leg cross-over, transitions and lunging at walk, trot and canter. Access to suitable surfaces and the training level of the horse and handler are the main barriers to using other movements. The majority (82%) of survey participants agreed or strongly agreed that a modified Patient-Specific Functional Scale would be useful for measuring complex movements. This knowledge of how equine clinicians are currently monitoring movement and using goal-setting will assist in designing a new outcome measure for quality of movement that includes both standardised and individualised measures. Abstract Outcome measures are essential for monitoring treatment efficacy. The lack of measures for quality of movement in equine physiotherapy and rehabilitation impairs evidence-based practice. To develop a new field-based outcome measure, it is necessary to determine movements most frequently observed during assessment of rehabilitation and performance management cases. An online survey of 81 equine sports medicine veterinarians and equine allied-health clinicians was conducted. The key movements identified included walk and trot on both firm and soft surfaces in a straight line and on a small circle, plus step back, hind leg cross-over, transitions and lunging at walk, trot and canter. The main barriers to observing some movements are access to suitable surfaces and the training level of the horse and handler. Subjective visual assessment of live or videoed horses was the most common method used to track progress of complex movements. The majority (82%) of survey participants agreed or strongly agreed that a modified Patient-Specific Functional Scale would be useful for measuring complex movements. Comments from all professions show a desire to have outcome measures relevant to their needs. This survey identified 24 in-hand movements, which can be used to form the foundation of a simple field-based outcome measure for quality of movement.

An approach to applied weight bearing asymmetry quantification using upper body kinematics in trotting horses

Thesis

Full-text available

Sep 2022

Christoffer Roepstorff

The ability to measure and quantify things has, for many years now, deepened humanity’s understanding of the world we live in. Within the field of equine biomechanics, the measurement and quantification of forces and movements have taught us a lot about horse locomotion and how it relates to the gait, performance, and welfare of the animal. One specific example of a health-related topic is weight-bearing lameness. The unwillingness of horse to fully load the painful limb, has been linked to measurable asymmetries between the vertical ground reaction forces, exerted by the limbs, while trotting. Similarly, vertical movement asymmetries of the head, withers, and pelvis have also been correlated to this type of lameness. At first glance, it might appear obvious that if a horse uses more vertical force in a left limb compared to a right while pushing against and off the ground, the resulting vertical movement of the mass it displaces should also become asymmetric. However, the horse also has a back connecting the fore- and hindlimb pairs and on top of this a neck with a head that protrude, much like a lever arm, from the cranial part of the body. The four-legged nature of the horse and the accompanying anatomical complexity can result in complicated vertical movement asymmetries that are not as obviously connected to the vertical ground reaction forces, as one might expect at a first glance. Advancements in technology and clinical research have brought objective measurement tools, specifically aimed at lameness evaluation, to the commercial market. Kinematic systems, e.g., inertial measurement units and marker based optical motion capture, are prevalent as they provide a relatively easier means of acquiring data compared to direct measurements of ground reaction forces, e.g., using force plates, force shoes or an instrumented treadmill. Applied objective lameness analysis requires that the measurement system is reliable, simple to use and that it outputs information that can be clinically interpreted. To cater to these needs, kinematic systems are often focused on the upper body movement, e.g., head, withers, and pelvis. While it is entirely possible to also capture limb kinematics, it can be favorable to exclude them as it results in less preparation of the horse and less equipment that could be in the way of palpation and diagnostic analgesia. However, not including limb data also makes it a challenge to automatically detect the gait and when the respective limbs have ground contact during each stride, which is essential information for calculating the related kinematic variables. Sampled signals might also contain noise and movement unrelated to the actual lameness, which must be removed to not pollute any extracted asymmetry variables. Finally, if kinetic weight-bearing asymmetry can be considered the symptom of lameness, then movement asymmetries are a symptom of the symptom. This means that figuring out how the movement is related to the forces and how the forces should then be clinically evaluated is of the essence. In this thesis it could be determined that pre-processing the kinematic signals either with a signal decomposition method or with a digital filter tuned to the horse’s stride frequency, could minimize the negative effects of the signal noise and unwanted components on the calculated upper body asymmetry variables. The various digital filters were evaluated using artificial vertical movement signals and data from 7 trotting horses with induced fore- and hindlimb lameness. For a fourth order high-pass Butterworth filter, the optimal cut-off frequency was found to be 72% of the stride frequency. A novel method for gait classification was presented, where the movement of the withers and the pelvis, captured with marker based optical motion capture, was used to distinguish walk from trot and left from right steps. A Quadratic Discriminant Analysis model was trained on 102 horses (60 819 steps) walking and trotting on a treadmill at varying speeds and with varying degrees of weight bearing asymmetries. Subsequently, the model was tested on 120 horses (21 845 steps) trotting and walking over ground during normal clinical evaluations on the straight line, on the circle, on soft, and on hard surfaces, resulting in a predicted accuracy of 99.98%. The connection between subjective lameness grades and kinetic weight-bearing asymmetry was investigated in 69 horses, clinically evaluated by two experienced veterinarians while being trotted on an instrumented treadmill, simultaneously measured with a marker based optical motion capture system. It was found that there was considerable overlap, in horses graded as sound and those graded as having subtle to mild lamenesses, when observing the peak vertical force differences and the head and pelvis vertical movement asymmetry. The association between peak vertical ground reaction force asymmetries and upper body movement asymmetries was investigated in 103 horses with varying degrees of weight-bearing asymmetries. The horses were trotted on an instrumented treadmill, simultaneously measured with a marker based optical motion capture system. It was shown that it was possible to model both fore- and hindlimb differences in peak vertical ground reaction forces as linear combinations of vertical movement asymmetry variables extracted from the head, withers and pelvis. The best models achieved root mean squared errors of 0.83% and 0.82% for the fore- and hindlimbs, respectively.

Commentary on Ladewig et al.: The uses, values, and limitations of the Ridden Horse Pain Ethogram

Article

Full-text available

Sep 2022
J VET BEHAV

„Riding Soundness“ – die orthopädische Gesundheit von Reitpferden auf dem Prüfstand

Article

Mar 2021

Es ist unumstritten, dass lahmende Pferde nicht geritten werden sollten. Doch die Kompetenz von Pferdebesitzern, eine Lahmheit bei ihrem Pferd zuverlässig zu erkennen, wird zunehmend hinterfragt. Dieses Thema wurde jetzt in einer Studie genauer untersucht.

Performance and rideability issues in horses as a manifestation of pain: A review of differential diagnosis and diagnostic approach

Article

Oct 2020
EQUINE VET EDUC

Nonspecific performance and rideability issues are more likely a manifestation of pain in the ridden horse rather than a true behavioural problem. A systematic and thorough investigation focusing on the potential presence of pain‐related conditions is thus crucial in horses with such complaints. It can, however, be challenging to determine whether the complaint is indeed related to pain, where the pain is located, and what the underlying cause is. This review describes the challenges of pain recognition in ridden horses and summarises the recently developed ridden horse ethograms that might enable pain to be assessed in an objective, valid and reliable way. Furthermore, the differential diagnosis and diagnostic approach to horses presenting potentially pain‐related performance and rideability issues are discussed.

A novel dynamometer for the standardisation of the force applied during distal forelimb flexion tests in horses

Article

Jul 2020
EQUINE VET EDUC

Variability in the technique employed for flexion tests may produce different responses and veterinary assessments. We propose a novel custom‐designed dynamometer and compare the results with the literature. Ten horses were enrolled in the present study, with a total of 20 forelimbs. The horses were found to be healthy based on orthopaedic and radiographic examination of the distal forelimb region, performed on both limbs. Lower forelimb flexion tests were performed by applying three different forces (75, 100 and 120 N), measured with a dynamometer, for one minute, with a time interval of 48 h between each test. Each horse was trotted before and after the flexion test. The experiment was videotaped, and the responses were assessed randomly and blindly by three experienced equine veterinarians. None of the horses responded with a lameness grade exceeding 1/5 on a numerical 6‐point scale. Two out of three veterinarians detected a increased degree of lameness between the minimum and the maximum force applied, while one veterinarian showed no change in the interpretation of the flexion test for all three applied forces. A mild agreement was detected between veterinarian A and B, applying a force of 100 N, and between A and C, with 120 N; a moderate agreement was found between veterinarian A and B, with 120 N. The chi‐square test showed that the results observed were only like the expected ones for 100 N. With a force of 100 N, there is no relationship between intensity and the evaluation of lameness; consequently, 100 N could be used to achieve a real standardisation of the lameness score. The use of the dynamometer was found to be easy and practical. It also enabled the applied force and the manipulation technique to be objectified.

Crooked tail carriage in horses: Increased prevalence in lame horses and those with thoracolumbar epaxial muscle tension or sacroiliac joint region pain

Article

Jun 2020
EQUINE VET EDUC

The relationship between lameness and crooked tail carriage (CTC) in horses is unclear. The objectives of this study were (i) to determine the association between CTC and lameness; (ii) among lame horses, to determine associations between CTC and lameness diagnosis, saddle slip, thoracolumbar range of motion (ROM), epaxial muscle tension and pain, and sacroiliac joint region (SIJR) pain, and (iii) to determine whether abolition of lameness and SIJR pain by diagnostic anaesthesia modified CTC. In this study, 520 lame and 170 nonlame sports horses were examined for CTC and other characteristics by one clinician (S.J.D.). All horses were evaluated when ridden. Lame horses were also assessed in hand and on the lunge. Crooked tail carriage, its direction, lameness, musculoskeletal and tack‐related parameters were recorded as binary variables and analysed using 2 × 2 contingency tables. Sacroiliac joint region pain was diagnosed using local anaesthesia. Standard errors are shown in square brackets. 32.5% of lame horses had CTC, compared with 5.3% of nonlame horses (odds ratio = 8.6 [confidence intervals 4.4, 16.7]; P = 2×10−12). Of 169 lame horses with CTC, 103 (60.9% [3.8%]) held their tail to the left. There was no association between the side of the predominant lame limb and CTC direction. However, CTC was more common (P = 0.005) in horses with hindlimb lameness (35.7% [2.4%], N = 401) compared with forelimb lameness (21.0% [4.1%], N = 100). Crooked tail carriage was associated with SIJR pain (P = 0.0007) and thoracolumbar epaxial muscle tension (P = 0.0007), but not with saddle slip, reduced thoracolumbar ROM or thoracolumbar epaxial muscle pain. Limitations of the study included the facts that nonlame horses were a convenience sample and lameness assessment, other clinical observations and determination of the presence of CTC were subjective, with potential for bias. Video recordings and photographs are available for verification of tail position. It was concluded that CTC is more prevalent in lame horses than nonlame horses. There is a positive association between CTC and hindlimb lameness, SIJR pain and thoracolumbar epaxial muscle tension.

Miscellaneous Musculoskeletal Conditions: MUSCULOSKELETAL EMERGENCIES

Chapter

Jun 2020

This chapter discusses miscellaneous equine musculoskeletal conditions, focusing on musculoskeletal (MSK) emergencies. Regardless of the type of MSK emergency, the first and most important step should always be to stabilize the overall systemic condition of the horse. MSK emergencies such as fractures, tendon/ligament lacerations, and septic synovial structures can occur in any type of horse and may be career ending or potentially life threatening if not treated appropriately. The chapter also discusses subtle, inconsistent abnormalities associated with poorly performing horses, proper saddle fit, prepurchase examination (PPE), and stance and gait anomalies. Poorly fitting or improperly used saddles and saddle pads often contribute to back pain and poor performance. The veterinarian's role in performing the PPE includes evaluating and advising on the serviceability of a horse for a prospective buyer's intended purpose. For the veterinarian it is usually easy to recognize moderate to severe neurological gait anomalies.

Effect of trotting speed and circle radius on movement symmetry in horses during lunging on a soft surface

Article

Full-text available

Dec 2012
AM J VET RES

Objective: To determine whether body lean angle could be predicted from circle radius and speed in horses during lunging and whether an increase in that angle would decrease the degree of movement symmetry (MS). Animals: 11 medium- to high-level dressage horses in competition training. Procedure: Body lean angle, head MS, and trunk MS were quantified during trotting while horses were instrumented with a 5-sensor global positioning system-enhanced inertial sensor system and lunged on a soft surface. Speed and circle radius were varied and used to calculate predicted body lean angle. Agreement between observed and predicted values was assessed, and the association between lean angle and MS was determined via least squares linear regression. Results: 162 trials totaling 3,368 strides (mean, 21 strides/trial) representing trotting speeds of 1.5 to 4.7 m/s and circle radii of 1.8 to 11.2 m were conducted in both lunging directions. Differences between observed and predicted lean angles were small (mean ± SD difference, -1.2 ± 2.4°) but significantly greater for circling to the right versus left. Movement symmetry values had a larger spread for the head than for the pelvis, and values of all but 1 MS variable changed with body lean angle. Conclusions and clinical relevance: Body lean angle agreed well with predictions from gravitational and centripetal forces, but differences observed between lunging directions emphasize the need to investigate other factors that might influence this variable. For a fair comparison of MS between directions, body lean angle needs to be controlled for or corrected with the regression equations. Whether the regression equations need to be adapted for lame horses requires additional investigation.

Usability of normal force distribution measurements to evaluate asymmetrical loading of the back of the horse and different rider positions

Article

Full-text available

Sep 2009
VET J

Pressure measurement devices in equine sports have primarily focused on tack (saddle pads and saddle fitting methods). However, saddle pressure devices may also be useful in evaluating the interaction and distribution of normal forces between the horse and rider, including rider position and riding technique. This study examined the validity, reliability, repeatability and possibilities of using a saddle pressure device to evaluate rider position. All measurements were performed using a standing horse. Validity was tested by calculating the correlation coefficient between measured normal force and the weight of the rider. Repeatability was tested by calculating intra-class correlation coefficients. The use of normal force measurements to evaluate horse–rider interaction was tested by adding a known weight to saddle or rider and collecting measurements with the rider sitting in four different positions.The device was found to be valid and reliable for force measurements when the measurement device was not replaced. The system could be used to determine the expected differences with added weight and in different rider positions. The normal force distribution measurement device proved to be a valid and reliable tool for studying the interaction between a rider and a static horse provided it is positioned carefully and consistently relative to both the horse and the saddle.

Kinetics and kinematics of the horse comparing left and right rising trot

Article

Full-text available

Apr 2009

At rising trot the rider sits alternately down on one diagonal pair of limbs and rises up on the other. The possible effects on asymmetry of locomotion induced by rising trot have rarely been studied. To demonstrate whether, and if so to what extent, rising trot causes asymmetrical loading in the vertical ground reaction force (VGRF) and/or asymmetrical effects on the locomotion pattern, comparing left and right side. Seven elite horses were ridden in left and right rising trot on a treadmill, while VGRF and kinematics were measured, with the horses' neck raised, the poll high and the bridge of the nose slightly in front of the vertical. Force loading was generally increased in the limbs of the sitting diagonal. The lumbar back was lower between mid-stances of the sitting and nonsitting stance, pelvic roll was limited and the tuber coxae heights were lower on the sitting side. Maximal hindlimb protraction was decreased. Forelimb retraction was increased and the T6 height decreased. The rider movement induces an uneven biphasic load that affects the back, pelvis and limb kinematics and VGRF. The generally advocated technique of alternating limbs when riding in rising trot is supported. The VGRF changes between rising on the left or right diagonal were distinct, but minor in absolute terms and therefore unlikely to have direct impact on the occurrence of locomotor injuries. Knowledge of an increase of asymmetry in rising trot is potentially useful for riders/trainers.

Influence of the force applied and its period of application on the outcome of the flexion test of the distal limb of the horse

Article

Full-text available

Dec 1997

The influence of the force applied and its period of application on the outcome of the flexion test of the distal forelimb was investigated in a group of eight sound horses. The degree of lameness after the flexion test was scored by a standard clinical classification, and by measuring the angle of maximum fetlock extension by means of the infrared light-based MacReflex gait analysis system. There was a good correlation between the clinical score and this electronically recorded kinematic parameter (r = 0.96). Both the force applied and the period of application affected the outcome of the test. Increasing the force applied by 25 per cent led to three horses being judged positive, instead of two when the normal force was applied. Doubling the time to 120 seconds resulted in four horses rather than two being classified as lame after the test. Reducing the force to 75 per cent or the time to 30 seconds resulted in all the horses being classified as sound. A flexion test lasting five minutes, either at 100 per cent force or at 75 per cent, classified six of the eight horses as lame. It is concluded that the flexion test should be defined more precisely in terms of these two factors in order to make its results more consistent and hence more useful.

Ground reaction force analysis of horses ridden at the walk and trot

Article

Jan 1991

Diagnosis and Management of Lameness in the Horse

Article

Jan 2003

Michael W Ross

Subjective analysis of exercise-induced changes in back dimensions of the horse: The influence of saddle-fit, rider skill and work quality

Article

Jun 2015

Recommendations concerning saddle-fit are empirical rather than based on scientific information. A saddle needs to fit the horse in motion, but there has been no investigation of whether the thoracolumbar region changes in dimensions in association with exercise. The objectives of this study were to quantify exercise-induced back dimension changes and to describe the association with work quality, saddle-fit and rider skill. Sixty-three sports horses in regular work were assessed prospectively in a non-random, cross-sectional survey. Thoracolumbar dimensions/symmetries were measured at predetermined sites before and immediately after a 30 min exercise period; widths for two levels at each site were measured and the shape-ratio calculated. The work quality and rider skill were graded and the presence of lameness and saddle-fit were recorded. Descriptive statistics, univariable and multivariable mixed-effect linear regression were performed to assess the relationship between horse-saddle-rider factors and changes in back dimensions. The mean back width after ridden exercise was greater compared with before exercise. Mean changes were greater in horses working correctly vs. those not working correctly, in those with correctly-fitting vs. ill-fitting saddles, and in horses ridden by good > moderately > poorly skilled riders. Back-width changes were significantly associated with saddle-fit. The back dimensions of horses working correctly change transiently with work. If a saddle does not fit properly before exercise, this increase in size does not occur. Saddle-fit should be assessed both before and after exercise to ensure correct fit. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prospective Evaluation of Forelimb Flexion Tests in Practice: Clinical Response, Radiographic Correlations, and Predictive Value for Future Lameness

Article

Many otherwise normal horses demonstrate a positive response to forelimb flexion tests. The response varies directly with the pressure applied to the limb. A positive response to flexion does not correlate with future lameness or lower limb radiographic abnormalities. Reliance on this test to diagnose subclinical lameness or predict future problems seems unwise. Author's address: P.O. Box 5231, Glendale, CA 91221. 1997 AAEP.

Recognition of lameness: Man versus machine

Article

Sep 2014
VET J

Sue Dyson

The interrelationship of lameness, saddle slip and back shape in the general sports horse population

Article

Dec 2013
EQUINE VET J

Saddle slip is usually blamed on saddle fit, crooked riders or horse shape, but may reflect hindlimb lameness. There are no studies of the frequency of occurrence of saddle slip and risk factors within a tested sample population of the general sports horse population. To quantify the frequency of saddle slip and to describe the association with lameness, thoracolumbar shape/symmetry, crooked riders and ill-fitting saddles. Non-random, cross-sectional survey using convenience sampling. Five hundred and six sports horses in normal work were assessed prospectively. Thoracolumbar shape/symmetry were measured at predetermined sites; the presence of lameness (in-hand and/or ridden) and saddle slip was recorded. Descriptive statistics, univariable and multiple logistic regression were performed to assess the relationship between horse-saddle-rider factors and saddle slip. The frequency of lameness, quadrilaterally reduced cranial phase of the stride or stiff, stilted canter was 45.7%, saddle slip 12.3%, left-right thoracolumbar shape asymmetries ≥ coefficient of variance of 8% (1.2 cm) 0.6%; 103/276 riders (37.3%) sat crookedly. The saddle consistently slipped to one side in 30.3% of horses with hindlimb lameness, compared with 5.4% with forelimb lameness, 17.4% with stiff, stilted canter, 20% with quadrilaterally reduced cranial phase of stride and 5.6% non-lame horses. Nineteen horses (30.6%) with saddle slip had no detectable hindlimb lameness, however, 14 had a gait abnormality, particularly in canter. Multivariable analysis revealed that saddle slip was significantly associated with hindlimb lameness and gait abnormalities (OR = 52.62, 95% confidence interval (CI) 17.4 - 159.7), saddle fitted with even contact and uniform flocking (OR = 15.49, 95% CI 1.9 - 125.5), riders sitting crookedly (OR = 6.32, 95% CI 2.9 - 13.7), a well-balanced saddle (OR = 3.05, 95% 1.4 - 6.9), and large back shape ratio at T18 (OR = 1.2, 95% 1.1 - 1.3). Many horses with hindlimb and/or forelimb lameness go unrecognised. Saddle slip may be a sign of hindlimb lameness. Education of the equestrian population to identify lameness and saddle slip is required.

Effect of turn direction on body lean angle in the horse in trot and canter

Article

Feb 2014
VET J

Turning is commonly used as a diagnostic aid in equine lameness examinations. Forces experienced on the circle differ from those in a straight line, necessitating an inward lean of the body and asymmetric head/pelvic excursion, which are important parameters for lameness investigations. To better understand gait adaptations to lungeing in normal horses, the effect of turn direction on body lean in trot and in canter warrants further investigation. In this study, it was hypothesised that, on average and independent of gait, the observed body lean angle would be consistent with the ratio between gravitational and centripetal acceleration, but with variations for individual horses showing differences between reins. Twenty horses were fitted with a global positioning system (GPS)-aided inertial measurement unit quantifying body lean angle, speed and circle radius in trot and canter in both directions. The difference between predicted (from speed and circle radius) and observed body lean (Δobs,pred) was compared between horses, directions and gaits using a generalised linear model. The mean speed and circle radius were 3.3 m/s and 4.9 m in trot and 4.5 m/s and 5.7 m in canter. Mean Δobs,pred was -1.1° (range -7.6 to 5.4°) in trot and -0.8° (range -7.6 to 8.3°) in canter and was significantly different between horses (P <0.0001) and directions (P <0.0001), but not between gaits (P = 0.14). Interactions between horse and direction (P <0.0001) and horse and gait (P = 0.011) were also significant. Horses leaned marginally less into the circle than predicted. However, this study provides additional evidence for horse specific adaptations, showing significant differences between horses and turn directions but not between gaits.

Effects of weight on equine workload and locomotion during treadmill exercise

Article

May 2010
EQUINE VET J

To answer the question whether an experienced rider or a dead weight influences a horse's workload and/or its locomotion, 9 well trained Dutch Warmblood horses, fully accustomed to treadmill exercise, underwent a submaximal standardised treadmill exercise test under 3 different conditions: unloaded, mounted by an experienced rider of 90 kg and loaded with 90 kg of lead. Heart rate was monitored continuously and plasma lactate concentrations were determined in venous jugular blood samples immediately before and 2 and 10 min after exercise. Temporal and angular stride variables were measured in fore- and hindlimbs at the walk (1.7 m/s), trot (4.0 m/s) and canter (7.0 m/s) with a modified CODA-3 computerised kinematic analysis system. Peak heart rates during exercise, and recovery heart rates thereafter were significantly lower in the unloaded horses compared to the mounted and lead-loaded horses. Plasma lactate concentrations immediately and 10 min after exercise were also significantly lower in the unloaded horses than in the mounted and lead-loaded horses. No differences were found in heart rate and plasma lactate concentration between the mounted and lead-loaded horses. Relative stance duration increased comparing the unloaded to the mounted and the lead-loaded horses (P<0.05). Small, but significant, differences were also observed in the fetlock extension and the maximal fetlock range of motion; both increased with loading. In conclusion, an experienced rider and a dead weight influence both workload and locomotion in exercising horses. Minimal differences were found between dead lead weight and a rider.

Which joint is most important for the positive outcome of a flexion test of the distal forelimb of a sound horse?

Article

Jan 2010

Proximal hindlimb flexion in the horse: Effect on movement symmetry and implications for defining soundness

Article

May 2012
EQUINE VET J

Reasons for performing the study: Flexion tests are a common tool during the prepurchase and clinical lameness examination, yet studies quantifying the effect of flexion, apart from distal forelimb flexion in sound horses, are sparse. Objectives: To investigate the effect of proximal hindlimb flexion on perceivable and measurable changes in movement symmetry in horses with objective movement symmetry falling within the margins of ‘sound’. Methods: Thirteen horses, selected based on objective movement symmetry, were instrumented with inertial sensors on left and right tuber coxae and over the os sacrum. Vertical movement symmetry was quantified at trot before and after proximal hindlimb flexion, with a repeat of flexion after 5 min. Video recordings of the horses were assessed visually. Results: Proximal hindlimb flexion introduced additive changes in movement symmetry to the individual baseline movement, with a tendency towards smaller effects with increasing stride number. The main systematic effect was a decrease in upward movement of the os sacrum following mid-stance of the flexed limb and an increase in upward movement following mid-stance of the nonflexed limb, also manifesting in a ‘hip hike’ of the flexed limb; these findings reflected increased movement asymmetry following flexion. Depending on individual baseline asymmetry, flexion can also increase movement symmetry. Conclusions: Proximal hindlimb flexion can exacerbate subtle asymmetry when performed carefully. Variation in measured symmetry following flexion within and between horses showed that the individual response to flexion is highly variable. Potential relevance: Proximal hindlimb flexion may elevate the asymmetry of a slightly lame limb above the threshold for visibility, thus assisting in the clinical gait examination. Further work is needed to examine the causes for a positive response to flexion and possible differences between sound and lame horses as well as horses of different athletic disciplines.

Vertical head and trunk movement adaptations of sound horses trotting in a circle on a hard surface

Article

Nov 2011

Trotting a horse in circles is a standard and important part of the subjective equine lameness examination, yet objective data on this form of locomotion are sparse. The aim of this study was to investigate the effect of trotting in a circle on head and trunk movement symmetry. Vertical movements of the head, withers, os sacrum and left and right tuber coxae were measured using inertial sensors as 12 sound horses were trotted on a hard surface in a straight line and in a circle on both reins. Seven asymmetry measures and hip hike were calculated for each horse for at least nine strides of comparable stride duration across the three conditions (deviation on horse level ≤3.7% stride duration). Trotting in a circle introduced systematic changes to the movement pattern of all five body landmarks, affecting most asymmetry measures. On average the asymmetry magnitude was comparable for midline locations between reins and for the tuber coxae on opposite reins with few exceptions, although individual horses showed unsystematic differences between the two reins. The results from this study showed that the thresholds for objective discrimination between lame and non-lame horses will need adjustment on the circle due to the observed asymmetry bias.

A comparative study of proximal hindlimb flexion in horses: 5 versus 60 seconds

Article

Sep 2011
EQUINE VET J

The flexion test is routinely used in lameness and prepurchase examinations. There is no accepted standard for duration of flexion or evidence that interpretation of results would differ with different durations of flexion. There will be no difference in interpretation of proximal hindlimb flexion for 5 or 60 s. Video recordings of lameness examinations of 34 client-owned horses were performed that included: baseline lameness, proximal hindlimb flexion for 60 s, and flexion of the same limb for 5 s. Videos were edited to blind reviewers to the hypothesis being tested. The baseline lameness video from each horse was paired with each flexion to make 2 pairs of videos for each case. Twenty video pairs were repeated to assess intraobserver repeatability. Fifteen experienced equine clinicians were asked to review the baseline lameness video followed by the flexion test and grade the response to flexion as either positive or negative. Potential associations between the duration of flexion and the likelihood of a positive flexion test were evaluated using generalised linear mixed models. A kappa value was calculated to assess the degree of intraobserver agreement on the repeated videos. Significance level was set at P<0.05. Proximal hindlimb flexion of 60 s was more likely to be called positive than flexion of 5 s (P<0.0001), with the likelihood of the same interpretation 74% of the time. The first flexion performed was more likely to be called positive than subsequent flexions (P = 0.029). Intra-assessor agreement averaged 75% with κ= 0.49. Proximal hindlimb flexion of a limb for 5 s does not yield the same result as flexing a limb for 60 s. Shorter durations of flexion may be useful for clinicians that have good agreement with flexions of 5 and 60 s.

Comparison of kinematic symmetry index calculations and the effects of straight and circular trotting

Article

Nov 2010
EQUINE VET J

When assessing lameness in horses, left to right ratios of kinematic parameters are often used to quantify movement symmetry. Different methods of symmetry related measures have been proposed and inertial sensor data was used to evaluate the application of 3 methods of symmetry calculation during straight and circular trotting. To compare 3 sensor based methods of symmetry index calculation to assess; tuber coxae vs. sacrum motion, the effects of circular trotting and effect of using whole trials in place of individual stride calculations. Inertial sensors were attached to the sacrum, left and right tuber coxae (LTC/RTC) of 21 non-lame horses. Straight and circular trotting data were collected. Symmetry indices based on vertical movement were calculated for each stride using 3 previously published methods. Method 2 (Fourier analysis) had significantly higher ratio values than method 1 (displacement amplitude ratio; tuber coxae) and methods 1 (displacement amplitude ratio; sacrum) and 3 (difference between LTC/RTC displacement). The effect of circular trotting within methods was highly variable, but was not significantly different between methods. No significant differences were found between whole trial and individual stride calculations. Method 2 when compared to method 1 underestimates the asymmetry present in a non-uniform way due to the use of squared amplitudes. Methods 2 and 3 become less accurate during circular trotting due to changes in amplitude timing. On the same data substantial differences in symmetry indices are found when using different methods and locations. Further differences exist in accuracy when used on circular data. Interpretation and direct comparison of different symmetry indices should be approached with caution.

Head and body centre of mass movement in horses trotting on a circular path

Article

Aug 2006
EQUINE VET J

Horses are often worked along a circular trajectory but the mechanics of turning have not been reported. To develop a methodology for kinematic analysis of horses during circling and to report preliminary findings describing movements of the total body centre of mass (COMbody). Seventy-five skin markers, distributed over the head, neck, trunk and limbs of 5 sound horses, were tracked in a global coordinate system at 120 Hz as the horses trotted around a small circle. Based on segmental inertial data, 3D positions of the segmental centres of mass and COMbody were calculated. Movements of COMbody were measured relative to the cylindrical vertical plane, the radius of which was defined by a marker overlying the sixteenth thoracic vertebra. During trotting, COMbody was high at the start and end of the diagonal stance phases and low in midstance. All horses leaned to the inside of the circle, with a tilt angle of mean +/- s.d. 14.8 +/- 2.8 degrees during the entire stride. In the transverse direction, COMbody swung from side to side reaching its most inward position around the time of contact of the inside forelimb and its most outward position around the time of contact of the outside forelimb. The centre of mass of the head and neck segments (COMhead/neck) had a symmetrical, double sinusoidal pattern in the vertical direction. All horses had the same motion pattern for COMhead/neck in the transverse direction but the mean position relative to the circle line varied between horses. Horses lean to the inside when turning around a small circle. COMhead/neck and COMbody showed 2 vertical oscillations in each stride, whereas there was a single mediolateral excursion that was not symmetrical to the inside and outside of the circle line. This study provides a first step toward understanding the mechanics of locomotion during turning, which has implications in the aetiology of injuries, the response to lungeing as a diagnostic technique and the incorporation of circles into rehabilitation exercises.

Can lameness be graded reliably?

Article

Jul 2011
EQUINE VET J

Sue Dyson

The difference in kinematics of horses walking, trotting and cantering on a flat and banked 10 m circle

Article

Mar 2011
EQUINE VET J

Locomotion adaptation mechanisms have been observed in horses, but little information is available in relation to banked and nonbanked curve locomotion, which might be important to optimise training environments. To determine if adaptation mechanisms in horses existed when moving on a banked compared to a flat curve and whether adaptation was similar in different gaits. Eight infrared cameras were positioned on the outside of a 10 m lungeing circle and calibrated. Retroreflective markers were used to define left and right metacarpus (McIII) and proximal phalanges (P1), metatarsus (MtIII), head and sacrum. Data were recorded at 308 Hz from 6 horses lunged at walk, trot and canter on a flat and 10° banked circle in a crossover design. Measurements extracted were speed, stride length, McIII inclination, MtIII inclination, relative body inclination and duty factor. Data were smoothed with a fourth order Butterworth filter with 30 Hz cut-off. ANOVA was used to determine differences between conditions and limbs. Adaptation mechanisms were influenced by gait. At canter inside forelimb duty factor was significantly longer (P<0.05) on a flat curve compared to a banked curve; at walk this was reversed. McIII inclination, MtIII inclination and relative body inclination were significantly greater (P<0.05) at trot and canter on a flat curve, so more inward tilt was found relative to the bearing surface. Adaptation to curved motion is gait specific. At faster gaits it appears that horses negotiate a banked curve with limb posture closer to body posture and probably with demands on the musculoskeletal system more similar to straight canter.

Which anatomical region determines a positive flexion test of the distal aspect of a forelimb in a nonlame horse?

Article

Sep 2010

The flexion test is used routinely as part of lameness and prepurchase examinations. However, little is known about the mechanisms that cause a positive response to a flexion test. To determine which anatomical regions play a role in a positive outcome of a flexion test of the distal aspect of a forelimb in a nonlame horse. Eight clinically sound Dutch Warmblood horses were subjected to a standardised flexion test (force 250 N, time 60 s) inducing a consistent lameness. To discriminate between different areas of the distal aspect of a forelimb, effects of various nerve blocks on the outcome of the flexion test were investigated. Low palmar digital, palmar at the abaxial aspects of the base of the proximal sesamoids, high palmar, ulnar and low 4-point nerve blocks were performed. Flexion test induced lameness was scored before and after each nerve block in separate sessions. The low palmar digital nerve blocks and nerve blocks of the palmar nerves at the abaxial aspect of the base of the proximal sesamoid bones had no significant effect on the flexion test induced lameness score. The ulnar, high palmar and, most dramatically, the low 4-point nerve blocks all caused a significant (P<0.05) reduction in the flexion test induced lameness score. Anatomical structures (soft tissue nor synovial structures) located distal to the metacarpophalangeal joint appear to contribute only minimally to the outcome of a positive flexion test of the distal aspect of a forelimb in a clinically nonlame horse. The structures in the region of, and including, the metacarpophalangeal joint appear to contribute most to a positive flexion test of the distal aspect of a forelimb in a nonlame horse. The flexion test of the distal aspect of a forelimb may be sensitive for investigating the metacarpophalangeal joint region in horses free from lameness, but may be less relevant for structures distal to this region.

Vertical forces on the horse's back in sitting and rising trot

Article

Nov 2009

In equestrian sports, it is generally assumed that rising and sitting trot load the horse's back differently. The objective of this study was to quantify the load on the horse's back in these riding techniques. Kinematic data of 13 riders were collected in rising and sitting trot. The time-history of the position of the rider's centre of mass (CoM) was calculated, and differentiated twice to obtain the acceleration of the CoM. The reaction force between the rider and the horse's back was calculated from the acceleration. Forces were divided by the body weight of the rider to obtain dimensionless forces. As expected, the computed average vertical force did not differ between riding techniques and was not significantly different from the body weight of the riders. At trot, two force peaks were present during one stride cycle. Both peaks in rising trot were significantly lower compared to sitting trot (peak 1: 2.54+/-0.30 versus 2.92+/-0.29; p<0.001; peak 2: 1.95+/-0.34 versus 3.03+/-0.32; p<0.001). This supports the general assumption that rising trot is less demanding for the horse than sitting trot.

The clinician's eye view of hindlimb lameness in the horse: Technology and cognitive evaluation

Article

Mar 2009

Sue Dyson

Flexion test of the metacarpophalangeal and interphalangeal joints and flexion angle of the metacarpophalangeal joint in sound horses

Article

Feb 1997

This paper describes the application of a measuring device 'Flextest' to control the effect of traction force and traction time during flexion tests of the distal limb joints of the forelimbs. The optimal force for a flexion test is 100 N, over 1 min. A higher force (150 N) was not harmful. A slightly positive flexion response (100 N/1 min) in a horse with no other clinical signs or radiographic abnormalities is not of clinical significance. Individual left and right flexion and extension angles are almost identical and do not depend on age. Stabled horses which have been rested or horses resting at pasture are less likely to have a positive flexion test than working horses.

Effects of treadmill inclination on kinematics of the trot in Dutch Warmblood horses

Article

Jun 1997
EQUINE VET J

To evaluate the effects of uphill trotting on stride characteristics, 6 well trained Dutch Warmblood horses trotted at 4 m/s on a horizontal and on an inclined (6%) treadmill. This was done under 3 different conditions, unloaded, mounted by an experienced 90 kg rider and loaded with 90 kg of lead, to study whether extra weight provoked more or different alterations than the incline per se. In all 3 test situations (unloaded, mounted and lead‐loaded), heart rates were significantly higher on the inclined treadmill than on the horizontal treadmill. Stride duration tended to increase on the inclined treadmill. Stance duration increased significantly on a slope, more in the hindlimbs than in the forelimbs. In the unloaded condition, maximal fetlock extension of the forelimb decreased on the incline, whereas maximal fetlock extension of the hindlimb and tarsal range of motion increased significantly on the slope in all 3 conditions. The overall effect was that on an inclined treadmill the hindlimbs seemed to carry more weight (higher maximal fetlock extension), and to provide greater propulsion (higher tarsal flexion and increased pro/retraction).

Variations in the force applied to flexion tests of the distal limb of horses

Article

Nov 1997

A pressure-sensitive device was developed to measure the force applied to flexion tests of the distal limb of horses. The mean force applied by a group of experienced clinicians was 150 N which results in a moment on the flexed fetlock joint of about 28.5 Nm. The coefficient of variation of the force applied by one experienced clinician was only about 12 per cent, but the coefficient of variation between clinicians was considerably higher (20 per cent), irrespective of whether the clinicians were considered to be experienced or not. The mean force applied by a group of women examiners (114 N) was significantly lower than that applied by the group of male examiners. It is concluded that the flexion test used in the clinical examination of the locomotor system of the horse should be better standardised.

Validity of Saddle Pressure Measurements Using Force- sensing Array Technology—Preliminary Studies

Article

Oct 1999
VET J

Back pain is a common and poorly understood clinical problem. An important factor in this regard is the induction or exacerbation of back pain from badly designed or poorly fitting saddles. This study used a pressure-sensing mat to investigate saddle fit. The aims of the study were to confirm the accuracy and reliability of the force-sensing array technology when used to measure pressure beneath the saddles of horses, and to collect some initial data from normal healthy horses with well-fitting saddles. Experiments were undertaken to establish that a linear relationship existed between the total force (weight) exerted and the pressure measured beneath the saddle, using both a wooden horse and a live horse in the standing position. Further studies were performed to demonstrate that characteristic changes of the centre of pressure occur while horses move at the walk, sitting trot, rising trot, and canter.

Use of the Flexion Test of the Distal Forelimb in the Sound Horse: Repeatability and Effect of Age, Gender, Weight, Height and Fetlock Joint Range of Motion

Article

Oct 2001

The flexion test of the distal limb is a commonly used clinical tool in both lame and sound horses. In the latter use it is given some predictive value. In recent studies it has been shown that examiner-related factors (force, time) may strongly influence the outcome of the test. In the present study, the possible influences of a number of horse-related factors and short- and long-term repeatability were investigated. Flexion tests were performed by the same researcher in 100 clinically sound horses under standardized conditions. The outcome of the test was scored on a 9-point semiquantitative scale. The maximum flexion angles of the fetlock joints were measured and the range of motion (ROM) of the fetlock joint was calculated. In the second part of the study, flexion tests were repeated, at intervals of 10 min, 30 min, 48 h and 6 months in 23 horses to assess repeatability. Over 60% of the 100 sound horses had a positive flexion test. Of these, about 50% showed a slight lameness, 35% a mild lameness, and 15% a distinct lameness. There was no influence of weight, height or ROM on the score of the flexion test. The outcome of the flexion test increased significantly with age and was significantly higher in mares than in geldings. When repeating the flexion test with short intervals of 10 and 30 min, the score increased significantly after the second test. Repeated flexion after 48 h did not result in a significantly different outcome. Over a 6-month period, the outcome of the test decreased significantly and the ROM increased significantly. It is concluded that most clinically sound horses have a (slightly) positive flexion test of the distal limb. This and the lack of long-term consistency of the test cast doubt on the presumption that a positive flexion test may be an indication for subclinical joint disorders and question the possible value of the test as a predictor of future joint-related problems. There exists a wide individual variation in ROM of the fetlock joint with, in sound horses, no relationship between ROM and the outcome of the flexion test. The factors age and gender should be taken into account when interpreting the results of a flexion test.

Effects of girth, saddle and weight on movements of the horse

Article

May 2005

Although the saddle is seen as one of the biggest causes of back pain, and weightbearing is seen as an important aetiological factor in 'kissing spine' syndrome (KSS), the effects of a saddle and weight on the back movements of the horse have never been studied. To determine the effects of pressure on the back, exerted by tack and weight, on movements of the horse. Weight has an extending effect on the horse's back and, as a compensatory mechanism to this extension, an alteration in pro- and retraction angles was expected. A similar but smaller effect was expected from a saddle only and a lungeing girth. Data were captured during treadmill locomotion at walk, trot and canter under 4 conditions: unloaded; with lungeing girth; saddle only; and saddle with 75 kg of weight. Data were expressed as maximal extension, maximal flexion angles, range of motion of L3 and L5 and maximal pro- and retraction angles of the limbs. At walk and trot, there was a significant influence on back kinematics in the 'saddle with weight' situation, but not in the other conditions. Overall extension of the back increased, but the range of movement remained the same. Limb kinematics changed in the sense that forelimb retraction increased. At canter, both the 'saddle with weight' and 'saddle only' conditions had a significant extending effect on the back, but there was no effect on limb kinematics. Weight and a saddle induce an overall extension of the back. This may contribute to soft tissue injuries and the KSS. The data from this study may help in understanding the reaction of the equine back to the challenges imposed by man when using the animal for riding.

Saddle pressure measuring: Validity, reliability and power to discriminate between different saddle-fits

Article

Oct 2006
VET J

Saddle-fit is recognised as an important factor in the pathogenesis of back problems in horses and is empirically being evaluated by pressure measurements in clinical practice, although not much is known about the validity, reliability and usability of these devices in the equine field. This study was conducted to assess critically a pressure measurement system marketed for evaluating saddle fit. Validity was tested by calculating the correlation coefficient between total measured pressure and the weight of 28 different riders. Reliability and discriminative power with respect to different saddle fitting methods were evaluated in a highly standardised, paired measurement set-up in which saddle-fit was quantified by air-pressure values inside the panels of the saddle. Total pressures under the saddle correlated well with riders' weight. A large increase in over-day sensor variation was found. Within trial intra-class correlation coefficients (ICCs) were excellent, but the between trial ICCs varied from poor to excellent and the variation in total pressure was high. In saddles in which the fit was adjusted to individual asymmetries of the horse, the pressure measurement device was able to detect correctly air-pressure differences between the two panels in the back area of the saddle, but not in the front area. The device yielded valid results, but was only reliable in highly standardised conditions. The results question the indiscriminate use of current saddle pressure measurement devices for the quantitative assessment of saddle-fit under practical conditions and suggest that further technical improvement may be necessary.

Equine lameness: clinical judgement meets advanced diagnostic imaging

S Dyson

Dyson S. Equine lameness: clinical judgement meets advanced diagnostic imaging. Proceedings of the American Association of Equine Practitioners 59th Annual Convention, Nashville, 2013. p. 92-122.