Evaluating Overall Performance in High-Level Dressage Horse-Rider Combinations by Comparing Measurements from Inertial Sensors with General Impression Scores Awarded by Judges.

In the sport of dressage, one or more judges score the combined performance of a horse and rider with an emphasis on the technical correctness of the movements performed. At the end of the test, a single score is awarded for the 'general impression', which considers the overall performance of the horse and rider as a team. This study explored original measures that contributed to the general impression score in a group of 20 horse-rider combinations. Horses and riders were equipped with inertial measurement units (200 Hz) to represent the angular motion of a horse's back and the motions of a rider's pelvis and trunk. Each combination performed a standard dressage test that was recorded to video. Sections of the video were identified for straight-line movements. The videos were analyzed by two or three judges. Four components were scored separately: gaits of the horse, rider posture, effectiveness of aids, and harmony with the horse. The main contributor to the score for gaits was stride frequency (R = -0.252, p = 0.015), with a slower frequency being preferred. Higher rider component scores were associated with more symmetrical transverse-plane trunk motion, indicating that this original measure is the most useful predictor of rider performance.

Adaptations in equine axial movement and muscle activity occur during induced fore- and hindlimb lameness: A kinematic and electromyographic evaluation during in-hand trot.

BACKGROUND: The inter-relationship between equine thoracolumbar motion and muscle activation during normal locomotion and lameness is poorly understood. OBJECTIVE: To compare thoracolumbar and pelvic kinematics and longissimus dorsi (longissimus) activity of trotting horses between baseline and induced forelimb (iFL) and hindlimb (iHL) lameness. STUDY DESIGN: Controlled experimental cross-over study. METHODS: Three-dimensional kinematic data from the thoracolumbar vertebrae and pelvis, and bilateral surface electromyography (sEMG) data from longissimus at T14 and L1, were collected synchronously from clinically nonlame horses (n = 8) trotting overground during a baseline evaluation, and during iFL and iHL conditions (2-3/5 AAEP), induced on separate days using a lameness model (modified horseshoe). Motion asymmetry parameters, maximal thoracolumbar flexion/extension and lateral bending angles, and pelvis range of motion (ROM) were calculated from kinematic data. Normalised average rectified value (ARV) and muscle activation onset, offset and activity duration were calculated from sEMG signals. Mixed model analysis and statistical parametric mapping compared discrete and continuous variables between conditions (α = 0.05). RESULTS: Asymmetry parameters reflected the degree of iFL and iHL. Maximal thoracolumbar flexion and pelvis pitch ROM increased significantly following iFL and iHL. During iHL, peak lateral bending increased towards the nonlame side (NLS) and decreased towards the lame side (LS). Longissimus ARV significantly increased bilaterally at T14 and L1 for iHL, but only at LS L1 for iFL. Longissimus activation was significantly delayed on the NLS and precipitated on the LS during iHL, but these clear phasic shifts were not observed in iFL. MAIN LIMITATIONS: Findings should be confirmed in clinical cases. CONCLUSIONS: Distinctive, significant adaptations in thoracolumbar and pelvic motion and underlying longissimus activity occur during iFL and iHL and are detectable using combined motion capture and sEMG. For iFL, these adaptations occur primarily in a cranio-caudal direction, whereas for iHL, lateral bending and axial rotation are also involved.

CONTEXTO: O relacionamento entre a movimentação toracolombar e a ativação muscular durante a locomoção normal e quando há claudicação é pouco compreendido. OBJETIVOS: Comparar a cinemática toracolombar e pélvica e a atividade do músculo longissimus dorsi (longissimus) em cavalos ao trote entre o momento inicial (baseline) e claudicação induzida no membro torácico (iFL) e pélvico (iHL). DELINEAMENTO DO ESTUDO: Estudo experimental controlado cruzado. METODOLOGIA: Dados cinemáticos tridimensionais das vertebras toracolombar e pelve, e eletromiografia de superfície (sEMG) bilateral do longissimus na T14 e L1 foram coletados de forma síncrona de cavalos clinicamente não claudicantes (n = 8) trotando no momento inicial (baseline), e durante iFL e iHL (2-3/5 AAEP), induzidos separadamente em dias distintos utilizando um modelo de claudicação (ferradura modificada). Parâmetros de movimentação assimétrica, flexão/extensão máxima da toracolombar e ângulos de virada lateral, e amplitude de movimento da pelve (ROM) foram calculados a partir dos dados de cinemática. O valor médio normalizado retificado (ARV) e início da ativação muscular, e término e duração da atividade foram calculados utilizando sinais de sEMG. Análise de modelo misto e mapeamento paramétrico estatístico compararam variáveis discretas e contínuas entre condições (α=0.05). RESULTADOS: Parâmetros de assimetria refletiram o nível de iFL e iHL. A flexão toracolombar máxima e a ROM da pelve aumentaram significativamente com iFL e iHL. Durante iHL, o pico de flexão lateral aumentou em direção ao lado não-claudicante (NSL) e diminuiu em direção ao lado claudicante (LS). Longissimus ARV aumentou significativamente para ambos os lados na T14 e L1 para iHL, mas apenas no LS para iFL. A ativação do longissimus foi significativamente retardado no NLS e precipitado no LS durante iHL, mas essa mudança de fase clara não foi observada no iFL. PRINCIPAIS LIMITAÇÕES: Esses achados precisam ser confirmados em casos clínicos. CONCLUSÕES: Adaptações significantes e distintas na movimentação toracolombar e pélvica e atividade do músculo longissimus ocorre durante iFL e iHL e são detectadas utilizando captura de movimento e sEMG. Para iFL, essas adaptações ocorrem primariamente na direção cranio-caudal, enquanto que em iHL, movimento lateral e rotação axial também estão envolvidos.

Reliable and clinically applicable gait event classification using upper body motion in walking and trotting horses.

Objectively assessing horse movement symmetry as an adjunctive to the routine lameness evaluation is on the rise with several commercially available systems on the market. Prerequisites for quantifying such symmetries include knowledge of the gait and gait events, such as hoof to ground contact patterns over consecutive strides. Extracting this information in a robust and reliable way is essential to accurately calculate many kinematic variables commonly used in the field. In this study, optical motion capture was used to measure 222 horses of various breeds, performing a total of 82 664 steps in walk and trot under different conditions, including soft, hard and treadmill surfaces as well as moving on a straight line and in circles. Features were extracted from the pelvis and withers vertical movement and from pelvic rotations. The features were then used in a quadratic discriminant analysis to classify gait and to detect if the left/right hind limb was in contact with the ground on a step by step basis. The predictive model achieved 99.98% accuracy on the test data of 120 horses and 21 845 steps, all measured under clinical conditions. One of the benefits of the proposed method is that it does not require the use of limb kinematics making it especially suited for clinical applications where ease of use and minimal error intervention are a priority. Future research could investigate the extension of this functionality to classify other gaits and validating the use of the algorithm for inertial measurement units.