Agneta Egenvall

Swedish University of Agricultural Sciences | SLU · Department of Clinical Sciences

As techniques for equine biomechanical research have become more accessible and affordable, the literature published in this area has exploded. Literature reviews have become more popular of late and, more specifically, several literature reviews in areas related to equine biomechanics have been published. A scoping review is a relatively new appro...

Horses in equestrian sports are commonly trained in arenas with prepared footing. Information on the number and variants of such arenas is generally unknown. This paper provides an overview of the primary construction types of riding surfaces in Sweden including details on composition, constructions principles, usage frequency, maintenance, and cos...

Background: Quantitative gait analysis offers objective information to support clinical decision-making during lameness workups including advantages in terms of documentation, communication, education, and avoidance of expectation bias. Nevertheless, hardly any data exist comparing outcome of subjective scoring with the output of objective gait an...

When collecting the horse, the rider influences stride length, forehand/hindquarters balance, and head-neck position. The study aim was to describe the vertical excursion of the withers and croup, and the sagittal cannon angles during collection and lateral exercises. Ten horses were ridden by five riders during 14 trials (1-5 per rider) on 10 m ci...

The study investigated between-rider differences in pelvic roll and pitch motion during horseback riding as the horse walked around circles without rein contact (walk on long reins), with rein contact, and with moderate collection. Ten horses were ridden by five riders on left and right 10 m circles, in a partly crossed design, yielding 14 trials....

Rein tension is relatively easy to measure, and the resulting data are useful for evaluating the interaction between horse and rider. To date, there have been a number of studies using different transducers, calibration methods and analytical techniques. The purpose of this paper is to make recommendations regarding the collection, analysis and rep...

Rein tension signals are, in essence, pressures applied on the horse’s mouth or nose, via the bit/noseband, by a rider or trainer. These pressures may feel uncomfortable or even painful to the horse and therefore it is important to reduce rein tension magnitude to a minimum. The aim of this study was to investigate the magnitude of a rein tension s...

Work on curved tracks, e.g. on circles, is commonplace within all forms of horse training. Horse movements in circles are naturally asymmetric, including the load distribution between inner and outer limbs. Within equestrian dressage the horse is expected to bend the back laterally to follow the circle, but this has never been studied scientificall...

When a rider maintains contact on the reins, rein tension will vary continuously in synchronicity with the horse's gait and stride. This continuous variation makes it difficult to isolate the rein tension variations that represent a rein tension signal, complicating interpretation of rein tension data from the perspective of horse-rider interaction...

Background: The increasing popularity of objective gait analysis makes application in pre-purchase examinations (PPE) a logical next step. Therefore, there is a need to have more understanding of asymmetry during a PPE in horses described on clinical evaluation as subtly lame. Objectives: To objectively compare asymmetry in horses raising minor...

Objective To investigate whether dog and cat owners and their pets share a risk of developing diabetes. Design Cohort study. Setting Register based longitudinal study, Sweden. Participants 208 980 owner-dog pairs and 123 566 owner-cat pairs identified during a baseline assessment period (1 January 2004 to 31 December 2006). Main outcome measure...

Many breeding organisations include a subjective scoring of rideability by a professional rider into their evaluation of sports horses, but the consistency and reliability of the scoring system is debateable. The aim of this study was to investigate (i) whether professional riders agree in their scoring of rideability, and (ii) whether rideability...

Background Biomechanical studies of walk, especially walk on the circle, are scarce, while circles or curved tracks are frequently used during equestrian activities. To study horse–rider–circle interactions on the circle, the first steps would be to investigate how the unridden, freely walking horse is influenced by circular movement, and then add...

Background: Left-right movement symmetry is a highly desirable characteristic in sport horses. Objectives: This study compared movement symmetry in well-trained dressage horses unridden and unrestrained, and ridden in a dressage frame, and investigated possible associations between gaits. Study design: Experimental study. Methods: Seven soun...

It has been suggested that one of the underlying causes of asymmetrical performance and left/right bias in sound riding horses is laterality originating in the cerebral cortices described in many species. The aim of this paper is to review the published evidence for inherent biomechanical laterality in horses deemed to be clinically sound and relat...

Background: Dog ownership is associated with increased physical activity levels and increased social support, both of which could improve the outcome after a major cardiovascular event. Dog ownership may be particularly important in single-occupancy households where ownership provides substitutive companionship and motivation for physical activity...

The superimposed influences of different head and neck positions (HNPs) and rider effects on symmetry in sound horses have not been studied. Our aim was to investigate the effects of HNPs and rider on the symmetry in minimum height of the withers at the walk. Seven high-level dressage horses were studied with and without rider in six HNPs: HNP1, fr...

In dressage, the performance of transitions between gaits and halts is an integral part of riding sessions. The study aimed to evaluate rein tension before, during and after the transitions between different gaits and the transitions into halts. The kinematic (inertial measurement units) data for the head and croup, and rein tension data, were coll...

The symmetry of the rider is highly relevant, and in the equestrian community it is generally thought that a symmetrical rider has a better possibility to influence the horse in an optimal way. The aim of the study was to analyse and compare frontal plane kinematics of the core body segments in ten riders while riding and while rocking a balance ch...

Clayton HM, Hampson A, Fraser P, White A, Egenvall A. Rider stability improves when riding in a flapless saddle versus a conventional saddle. PlosOne 2018;13(6): e0196960. Performed with approval of the MSU animal care and use committee. No competing interests declared. ROM of the rider's COP in AP and ML directions will be smaller with the flaples...

Objective To study the association between dog ownership and cardiovascular risk factors. Design A nationwide register–based cohort study and a cross-sectional study in a subset. Setting A cohort of 2 026 865 participants was identified from the Register of the Total Population and linked to national registers for information on dog ownership, pr...

For efficient rider-horse communication, the rider needs to maintain a balanced position on the horse, allowing independent and controlled movements of the rider’s body segments. The rider’s balance will most likely be negatively affected by postural asymmetries. The aims of this study were to evaluate inter-segmental symmetry of movements of the r...

Supplementary Item 1. Model output evaluating asymmetry parameters and stride duration.

General additive modelling (GAM-modelling) is an exploratory technique that can be used on longitudinal (time series) data, e.g. rein tension, over a period of time. The aim was to apply GAM-modelling to investigate changes in rein tension during a normal flatwork training session. Six riders each rode two or three of their horses (n=17 horses) dur...

The walk and trot are inherently symmetrical gaits, making them potentially suitable for the detection of left-right asymmetries. The aims of this study were to describe asymmetrical vertical excursions of the withers at walk in non-lame high-level dressage horses and to seek associations between these asymmetric movements and other kinematic varia...

The marker set up. The markers used in the current study were those on the sixth, tenth and thirteenth thoracic vertebrae (T6, T10, T13), third sacral vertebra (S3), spina scapula (3), elbow joint space (5) and lateral fore and hind hoof walls (not numbered). (TIF)

Raw data for vertical positions of T6, T10, T13 and means of the vertical positions of the tubera spina scapulae markers for the trials in median speed for each horse. The curves showing vertical positions are centered around zero. For the ground reaction forces, the upper tracks are for the forelimbs and the lower tracks are for the hind limbs; in...

Stance minimum vertical positions of T6 plotted against stance minimum vertical positions of other midline and forelimb markers evacuated from the time point during early stance of the left forelimb (only values for left forelimb stance are plotted to avoid stride-level clustering within trial). Minimal vertical positions for markers on the tuber s...

The data used for the statistical analysis. (XLSX)

Distributions of trial-level models independent data tested in kinetic and kinematic models. All variables are expressed as differences between left and right. Data—see S1 Table. (PDF)

Video of horse 2. Original speed 1.58 m/s; shown at 50% of original speed. (MP4)

Saddle slip, defined as a progressive lateral displacement of the saddle during ridden exercise, has recently been given attention in the scientific press as a potential sign of lameness. The aim of this study was to objectively quantify the normal lateral movement (oscillations) of the saddle relative to the horse in non-lame horses, and associate...

Data used for analysis. (XLSX)

Example of raw data. Lateral movement of the saddle and L3 in one horse for left rising, right rising and sitting trot. Higher y-axis values imply movement to the right and lower values movement to the left. (TIF)

The purpose of a saddle is to improve the rider’s safety, security, and comfort, while distributing the forces exerted by the rider and saddle over a large area of the horse’s back without focal pressure points. This study investigates the effects on rider stability of an innovative saddle design that differs from a conventional saddle in having no...

The debate on proper head and neck positions (HNP) in horse training is lively, but little is known about the biomechanical effects of various HNPs in horses ridden at walk. The aim was to quantify the influence of different HNPs on the kinematics of horses ridden at walk. The standard competition position (HNP2) was compared to a free, unrestraine...

Background The main criteria for lameness assessment in horses are head movement for forelimb lameness and pelvic movement for hindlimb lameness. However, compensatory head nod in horses with primary hindlimb lameness is a well‐known phenomenon. This compensatory head nod movement can be easily misinterpreted as a sign of primary ipsilateral foreli...

This study reports tension in the left and right reins when riding a horse simulator that moved only in the sagittal plane. The objective was to determine whether asymmetries in rein tension of novice riders at the rising trot, canter, and halt were present, and if so, to investigate their relationship with the rider’s handedness. The experimental...

The development of safety and quality standards for equestrian surfaces needs to be based on objective, repeatable measurements which allow comparisons between surfaces. These measurements should incorporate the assessment of surface performance by riders. This study provides data from objective and subjective assessment of functional properties of...

Recent studies evaluating horses in training and considered free from lameness by their owners have identified a large proportion of horses with motion asymmetries. However the prevalence, type and magnitude of asymmetries when trotting in a straight line or on the lunge have not been investigated. The aim of this study was to objectively investiga...

Data set used for the data analysis. Excel sheet containing description of variables used for the analysis. Sheet ‘reduced_content_rowsred’ contains descriptions of the data and explanations of what the variable names mean. Sheet ‘data_rowsred’ contains the data. (XLSX)

Least square means of univariable fixed effects from mixed models. Univariable fixed effects with owner as a random effect for two dependent variables (PDmin and PDmax) for variables with group-level p-values <0.05. BT- back-transformed estimate and standard error (SE). NS- non significant pairwise comparison. (XLSX)

Table S1. Results from the full model (n = 2,066) compared to the results from the sensitivity analyses (n = 730).

Background: Diabetes in cats resembles type 2 diabetes in people. The etiology is not fully understood, but both genetic and environmental factors are believed to contribute. Objectives: To assess the associations of environmental risk factors with diabetes in cats. Animals: Cats with a diagnosis of diabetes (n = 396) insured by a Swedish insu...

Supplementary Item 1: Multivariable modelling of the association between kinematic data and horse and surface

The objectives were to compare sagittal plane posture of the pelvis, trunk and head of elite dressage riders when they ride actively to train the horse versus sitting passively and following the horses' movements at trot, and to evaluate the effects of these changes in rider posture on load distribution on the horse's back. Synchronised motion capt...

Supplementary Item 1: The instructions and questions to the veterinarians participating in the survey.

Supplementary Item 2: Objective and subjective evaluation of the horses in the 47 videos (repeats excluded).

Supplementary Item 3: Number of videos (total 45) on horses with the different combinations of fore and hindlimb asymmetry categories during lungeing.

The use of tack (equipment such as saddles and reins) and especially of bits because of rein tension resulting in pressure in the mouth is questioned because of welfare concerns. We hypothesised that rein tension patterns in walk and trot reflect general gait kinematics, but are also determined by individual horse and rider effects. Six professiona...

Foot pronation is a common postural condition that is related to postural asymmetry, and that may affect performance in a variety of sports. The aim of this study was to evaluate whether unmounted riders (n=18) with predominantly right or left foot pronation had an increased contralateral pelvic drop during stance of the more pronated foot when wal...

Recent studies evaluating owner sound horses have identified a large proportion of horses with motion asymmetries but the prevalence, type and magnitude of asymmetries have not been investigated. The increasing use of objective lameness evaluation necessitates a further characterisation of the differences between lameness and motion asymmetries. To...

The aim of this study was to describe the incidence of feline dystocia with respect to breed. The data used were reimbursed claims for veterinary care insurance and/or life insurance claims in cats registered in a Swedish insurance database from 1999-2006. The incidence rates for dystocia were about 22 cats per 10,000 cat years at risk, 67 per 10,0...

Diabetes mellitus (DM) is a common endocrinopathy in cats. Most affected cats suffer from a type of diabetes similar to type 2 diabetes in humans. An increasing prevalence has been described in cats, as in humans, related to obesity and other lifestyle factors. To describe the incidence of DM in insured Swedish cats and the association of DM with d...

Rein tension signals are commonly used to communicate the intended speed, direction, and head carriage to the horse during horseback riding. Rein tension has previously been recorded relative to gait, exercises, and turning maneuvers. The aim of this study was to target the between-gait and between-exercise variation in rein tension, controlling fo...

Kidney disease is an important cause of morbidity and mortality in dogs. Knowledge about the epidemiology of kidney disease in the dog population is valuable and large-scale epidemiological studies are needed. The aim of the present study was to use insurance data to estimate kidney-related morbidity and mortality in the Swedish dog population. Ins...

Riders generally use reins as a means for communication with the horse. At present, the signalling pattern is poorly understood. The aim of this study was to illustrate and analyse the rein tension patterns in a number of rider/horse combinations across a variety of exercises in the canter gait. Our hypothesis was that some riders will follow the m...