Topic:Asymmetry
Asymmetry in horses refers to the unevenness or lack of uniformity in the body or movement, which can occur naturally or as a result of injury, training, or anatomical variations. It is commonly observed in limb length, muscle development, and gait patterns. Asymmetry can impact a horse's performance, comfort, and susceptibility to injury, thus it is a topic of interest in veterinary medicine, biomechanics, and equine sports science. Assessing asymmetry involves various methods, including visual inspection, motion analysis, and diagnostic imaging. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, assessment techniques, and implications of asymmetry in equine health and performance.
Associations between Racing Thoroughbred Movement Asymmetries and Racing and Training Direction. Racehorses commonly train and race in one direction, which may result in gait asymmetries. This study quantified gait symmetry in two cohorts of Thoroughbreds differing in their predominant exercising direction; we hypothesized that there would be significant differences in the direction of asymmetry between cohorts. Methods: 307 Thoroughbreds (156 from Singapore Turf Club (STC)-anticlockwise; 151 from Hong Kong Jockey Club (HKJC)-clockwise) were assessed during a straight-line, in-hand trot on firm ground with inertial sensors on their head and pelvis quantifying differences between the minim...
Objective movement asymmetry in horses is comparable between markerless technology and sensor-based systems. A markerless artificial intelligence (AI) system for lameness detection has recently become available but has not been extensively compared with commonly used inertial measurement unit (IMU) systems for detecting asymmetry under field conditions. Objective: Comparison of classification of asymmetric limbs under field conditions and comparison of normalised asymmetry data using a markerless AI system (SleipAI; recorded on a tripod mounted iPhone 14pro [SL]); the Equinosis Q Lameness Locator (LL); the EquiMoves (EM); and subjective evaluation (SE). Methods: Descriptive clinical study. Methods: S...
Classification performance of sEMG and kinematic parameters for distinguishing between non-lame and induced lameness conditions in horses. Despite its proven research applications, it remains unknown whether surface electromyography (sEMG) can be used clinically to discriminate non-lame from lame conditions in horses. This study compared the classification performance of sEMG absolute value (sEMGabs) and asymmetry (sEMGasym) parameters, alongside validated kinematic upper-body asymmetry parameters, for distinguishing non-lame from induced fore- (iFL) and hindlimb (iHL) lameness. Bilateral sEMG and 3D-kinematic data were collected from clinically non-lame horses ( = 8) during in-hand trot. iFL and iHL (2-3/5 AAEP) were induced...
Objective Assessment of Equine Locomotor Symmetry Using an Inertial Sensor System and Artificial Intelligence: A Comparative Study. In horses, quantitative assessment of gait parameters, as with the use of inertial measurement units (IMUs) systems, might help in the decision-making process. However, it requires financial investment, is time-consuming, and lacks accuracy if displaced. An innovative artificial intelligence marker-less motion tracking system (AI-MTS) may overcome these limitations in the field. Our aim was to compare the level of agreement and accuracy between both systems and visual clinical assessment. Twenty horses underwent locomotion analysis by visual assessment, IMUs, and AI-MTS systems, under the foll...
Changes in Head and Pelvic Movement Symmetry after Diagnostic Anaesthesia: Interactions between Subjective Judgement Categories and Commonly Applied Blocks. Limited evidence is available relating gait changes to diagnostic anaesthesia. We investigated associations between specific movement patterns and diagnostic anaesthesia of different anatomical structures in a retrospective analysis. Referral-level lameness cases were included with the following criteria: presence of diagnostic anaesthesia of a forelimb and/or hind limb; subjective efficacy classified as "negative", "partially positive", or "positive"; quantitative gait data available from inertial measurement units. Gait changes were calculated for three forelimb (palmar digital, abaxial sesa...
Pilot study of locomotor asymmetry in horses walking in circles with and without a rider. Horses commonly show asymmetries that manifest as left (L)-right (R) differences in vertical excursion of axial body segments. Moving on a circle confounds inherent individual asymmetries. Our goals were to evaluate individual and group asymmetry patterns and compare objective data with subjective impressions of side preference/laterality in horses walking on L and R circles. Unassigned: Fifteen horses walked on L and R circles unridden and ridden on long and short reins. Optical motion capture (150 Hz) tracked skin-fixed markers. Variables were trunk horizontal angle; neck-to-trunk angle; ver...
Asymmetry Thresholds Reflecting the Visual Assessment of Forelimb Lameness on Circles on a Hard Surface. The assessment of lameness in horses can be aided by objective gait analysis tools. Despite their key role of evaluating a horse at trot on a circle, asymmetry thresholds have not been determined for differentiating between sound and lame gait during this exercise. These thresholds are essential to distinguish physiological asymmetry linked to the circle from pathological asymmetry linked to lameness. This study aims to determine the Asymmetry Indices (AIs) with the highest power to discriminate between a group of sound horses and a group of horses with consistent unilateral lameness across bo...
Comparing Inertial Measurement Units to Markerless Video Analysis for Movement Symmetry in Quarter Horses. With an increasing number of systems for quantifying lameness-related movement asymmetry, between-system comparisons under non-laboratory conditions are important for multi-centre or referral-level studies. This study compares an artificial intelligence video app to a validated inertial measurement unit (IMU) gait analysis system in a specific group of horses. Methods: Twenty-two reining Quarter horses were equipped with nine body-mounted IMUs while being videoed with a smartphone app. Both systems quantified head and pelvic movement symmetry during in-hand trot (hard/soft ground) and on the l...
Normal variation in pelvic roll motion pattern during straight-line trot in hand in warmblood horses. In horses, hip hike asymmetry, i.e. left-right difference in hip upwards movement during hind limb protraction in trot, is a crucial lameness sign. Vertical hip movements are complex, influenced by both pelvic roll and pelvic vertical motion. Veterinarians find it challenging to identify low-grade lameness, and knowledge of normal variation is a prerequisite for discerning abnormalities. This study, which included 100 clinically sound Warmblood horses, aimed to describe normal variation in pelvic roll stride patterns. Data were collected during straight-line trot in hand using optical motion c...
An objective study into the effects of an incline on naturally occurring lameness in horses. The clinical examination of lame horses in real world settings often requires the use of sloped surfaces. This pilot study aimed to evaluate the effects of uphill and downhill locomotion on asymmetry in horses with naturally occurring lameness affecting forelimbs and hindlimbs. Ten horses (8-19 years) with forelimb lameness and eight horses (7-16 years) with hindlimb lameness were fitted with inertial sensors at the poll, withers, sacrum and both tuber coxae. Data were collected whilst the horses were trotted in hand on a level surface (20 mm) among conditions in individual horses. Two horse...
Footedness and Postural Asymmetry in Amateur Dressage Riders, Riding in Medium Trot on a Dressage Simulator. This study explored the relationship between footedness and postural asymmetry in equestrian riders. 28 female riders completed the Waterloo Footedness Questionnaire- Revised (WFQ-R), giving a score for footedness. They then took part in a test on a riding simulator where measures of saddle force, stirrup force, and degree of lateral tilt of the pelvic, trunk, and shoulder segments were taken over a period of 20 seconds in trot. Symmetry indices were calculated for stirrup force and saddle force. There were no significant correlations between WFQ-R score and any of the measures of postural sym...
Facilitating new movement strategies: Equine assisted physiotherapy for children with cerebral palsy. Equine Assisted Physiotherapy (EAPT) offers children with cerebral palsy (CP) opportunities for new movement experiences, and may influence movement qualities. Descriptions of how, and to what extent EAPT affects trunk control is missing. The aim of this study was to explore if, and how changes in trunk control and changes in other movement aspects were observable in children with CP during EAPT, and if potential changes in trunk control could be measured. Methods: A multiple case study with a mixed methods design was completed. Two children with CP, GMFCS grade 1, were observed using video du...
A simple method of equine limb force vector analysis and its potential applications. Ground reaction forces (GRF) measured during equine gait analysis are typically evaluated by analyzing discrete values obtained from continuous force-time data for the vertical, longitudinal and transverse GRF components. This paper describes a simple, temporo-spatial method of displaying and analyzing sagittal plane GRF vectors. In addition, the application of statistical parametric mapping (SPM) is introduced to analyse differences between contra-lateral fore and hindlimb force-time curves throughout the stance phase. The overall aim of the study was to demonstrate alternative methods of eva...
Head, withers and pelvic movement asymmetry and their relative timing in trot in racing Thoroughbreds in training. Horses show compensatory head movement in hindlimb lameness and compensatory pelvis movement in forelimb lameness but little is known about the relationship of withers movement symmetry with head and pelvic asymmetry in horses with naturally occurring gait asymmetries. Objective: To document head, withers and pelvic movement asymmetry and timing differences in horses with naturally occurring gait asymmetries. Methods: Retrospective analysis of gait data. Methods: Head, withers and pelvic movement asymmetry and timing of displacement minima and maxima were quantified from inertial sensors in 16...
The Osteometry of Equine Third Phalanx by the Use of Three-Dimensional Scanning: New Measurement Possibilities. This study consisted in analyzing the asymmetry between bilateral third phalanges (coffin bones) in cold-blood horses based on the angle range of the plantar margin of the bone. The study employed a scanner projecting a hybrid set of images, consisting of sinusoidal stripes preceded by a Gray code sequence. As it turned out, three-dimensional scanning can be used to effectively determine the angle range for a selected portion of the studied bone. This provides broad possibilities for osteometric studies, as it enables the determination of angle distribution in a given fragment. The results obt...
A galloping quadruped model using left-right asymmetry in touchdown angles. Among quadrupedal gaits, the galloping gait has specific characteristics in terms of locomotor behavior. In particular, it shows a left-right asymmetry in gait parameters such as touchdown angle and the relative phase of limb movements. In addition, asymmetric gait parameters show a characteristic dependence on locomotion speed. There are two types of galloping gaits in quadruped animals: the transverse gallop, often observed in horses; and the rotary gallop, often observed in dogs and cheetahs. These two gaits have different footfall sequences. Although these specific characteristics in quadr...
Posture, flexibility and grip strength in horse riders. Since the ability to train the horse to be ambidextrous is considered highly desirable, rider asymmetry is recognized as a negative trait. Acquired postural and functional asymmetry can originate from numerous anatomical regions, so it is difficult to suggest if any is developed due to riding. The aim of this study was therefore to assess symmetry of posture, strength and flexibility in a large population of riders and to determine whether typical traits exist due to riding. 127 right handed riders from the UK and USA were categorized according to years riding (in 20 year increments) and their...
An investigation of the relationship between hindlimb lameness and saddle slip. We have observed saddle slip consistently to one side because of a crooked rider, an ill-fitting saddle, asymmetry in a horse's thoracolumbar shape and lameness. Currently, there are no objective data to permit assessment of the relative importance of each factor. Objective: To document the frequency of occurrence of saddle slip in horses with hindlimb lameness compared with other horses. To describe the effect of lameness characteristics and grade, the abolition of lameness by diagnostic analgesia, breed, size, thoracolumbar shape and symmetry and the rider's weight. Methods: One hundred and ...
A preliminary study into rider asymmetry within equitation. Rider asymmetry is anecdotally associated with underperformance and injury. In this study, rider axial rotation (AR) and shoulder angle displacement (SAD) were measured using video analysis, and leg length inequality (LLI) was measured to assess any correlation between LLI, AR and SAD. Two video cameras, recording transverse and sagittal views, simultaneously filmed each of 17 female riders in walk, trot, and left and right canter. The rider's shoulder angles relative to the cranial caudal line were measured at each limb impact for a complete stride cycle. All riders exhibited left AR and a gr...
Radiological assessment of the effects of a full rolling motion shoe during asymmetrical bearing. The authors used a new radiological method to assess asymmetrical articular compression of the interphalangeal joints. This method was based on the measurements of 3 angles obtained on dorsopalmar radiographs. Variations of these angles were studied during experimental asymmetrical bearing on unshod feet. It was concluded that 2 angles were interesting parameters to assess asymmetrical articular compression and to define the position of the phalanx in the horny box. Furthermore, variations of these angles induced by experimental asymmetrical bearing were compared without shoe, with a standard ...
Directional and anteroposterior asymmetry of common white markings in the legs of the Arabian horse: response to selection. Arabian bay horses manifest, on the average, more common white markings in their hind legs than their forelegs (anteroposterior asymmetry) and more common white markings in their left legs than their right legs (directional asymmetry). To determine if genetic variation exists for these types of asymmetry, the phenotypic response was studied in bay foals when their dams and sires were selected for the directions of fore-hind and left-right differences. In the fore-hind studies, the quantitative shifts in the bay foals were in the direction specified by the selection scheme and the observed devi...
Influence of stochastic events on the phenotypic variation of common white leg markings in the Arabian horse: implications for various genetic disorders in humans. One method of assessing the influence of stochastic events on phenotypic variation is to study morphological differences in paired limbs of the same individual. These limbs have identical genotypes and similar intra-uterine environments and are analogous to monozygotic twins. Common white leg markings have a multifactorial mode of inheritance in the Arabian horse. Asymmetry occurs frequently for these markings. Using computerized registration records obtained from the Arabian Horse Registry of America, Inc., the types of markings were quantified in the left foreleg and left hind leg of bay and...