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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 measures that contribute 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 angular motion of the horse’s back, and the motion of the 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 the 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. Gait scores and all three rider scores were associated with dynamic symmetry of the trunk indicating that this measure was the most useful predictor of rider performance.

During turning, horses lean inwards to generate a centripetal force, but sport horses are trained to turn with a more vertical posture. The objective was to compare trunk roll angles in dressage horses performing true canter (TC) and counter canter (CC). Sixteen high-level dressage horses were ridden by their trainers in a 20×60 m arena with sand-fibre footing. Trunk roll angle was measured using an inertial measurement unit attached to mid-ventral girth. Data were analysed for 10 strides/horse on 20 and 10 m circles in TC and CC in each direction. Positive roll values indicated the trunk rolled down on the inside of the circle. Descriptive statistics were calculated and compared using a GLM and post hoc tests (P

Many factors influence the overall score for a dressage test, which makes it challenging and complex to establish key performance determinants. The aim was to identify an objective locomotory measure to quantify overall rider performance in dressage. The chosen variable should be both easy to collect and useful in a practical context. Twenty dressage horse/ rider combinations (Int1-GP) were equipped with inertial measurement units (IMU’s, 200 Hz) attached to the rider’s sacrum and thorax. Transverse dynamic trunk symmetry and pelvis symmetry (symmetry measures) and trunk-to-pelvis 3-dimensional coordination variability (within rider coordination measure) were collected from the IMU’s during straight line walk, trot and canter on left and right reins with ≥9 strides/condition. Sixteen United States Dressage Federation senior judges evaluated the movements of interest from video footage with 2-3 judges scoring each rider’s performance in the movements of interest and awarding collective scores to represent the overall impression of each rider’s performance. Stepwise linear regression was used to seek associations between objective measurements from the IMUs and subjective scores awarded by the judges. The variable dynamic trunk symmetry was the strongest predictor of collective scores, specifically the score for rider position (R=0.357, P=0.001). The rider’s dynamic pelvic symmetry was a strong predictor of the judged score for the walk (R=0.607, P=0.010), but no relationships were found between objective and judged scores for trot or canter. The overall impression of trunk posture may be influential in judges’ collective scores. Symmetrical pelvic motion appears to be a key factor in producing a high-quality walk.

BACKGROUND: There is a paucity of research describing the gait pattern of lame horses at the walk.OBJECTIVES: To describe the changes in motion pattern and vertical ground reaction forces (GRFz) in horses with induced forelimb lameness at the walk and compare those changes with the changes observed at the trot.STUDY DESIGN: Experimental study.METHODS: In 10 clinically sound Warmblood horses, moderate forelimb lameness was induced using a sole pressure model followed by trot and walk on a treadmill. Kinematic data were collected using 3D optical-motion-capture, and GRFz by an instrumented treadmill. Mixed models were used to compare sound baseline versus forelimb lameness (significance was set at p<0.05).RESULTS: Lameness induction significantly reduced peak GRFz on the second force peak, and vertical impulse in the lame limb. Stride and stance duration in all limbs were reduced. Lameness significantly affected the vertical movement symmetry of the head and withers. Maximum limb retraction angle, fetlock extension and protraction speed were reduced in the lame limb. Body centre of mass translation was reduced in the side-to-side direction and increased in the vertical and fore-aft directions. Several compensatory kinetic and kinematic changes were observed in the non-lame limbs. The observed changes in both kinetics and kinematics were generally smaller at walk with fewer variables being affected, compared to the trot.MAIN LIMITATIONS: Only one degree and type of orthopaedic pain (sole pressure) was studied.CONCLUSIONS: Compensatory strategies of forelimb lameness at the walk include alteration of several kinetic and kinematic parameters and have some specific patterns and inter-individual differences that are not seen at the trot. However, much like at the trot, head movement and forelimb vertical force symmetry seem to be the most useful parameters to detect forelimb lameness at walk.

For centuries humans have been fascinated by the natural beauty of horses in motion and their different gaits. Gait classification (GC) is commonly performed through visual assessment and reliable, automated methods for real-time objective GC in horses are warranted. In this study, we used a full body network of wireless, high sampling-rate sensors combined with machine learning to fully automatically classify gait. Using data from 120 horses of four different domestic breeds, equipped with seven motion sensors, we included 7576 strides from eight different gaits. GC was trained using several machine-learning approaches, both from feature-extracted data and from raw sensor data. Our best GC model achieved 97% accuracy. Our technique facilitated accurate, GC that enables in-depth biomechanical studies and allows for highly accurate phenotyping of gait for genetic research and breeding. Our approach lends itself for potential use in other quadrupedal species without the need for developing gait/animal specific algorithms., QC 20201127Correction: DOI:10.1038/s41598-021-88880-7

For centuries humans have been fascinated by the natural beauty of horses in motion and their different gaits. Gait classification (GC) is commonly performed through visual assessment and reliable, automated methods for real-time objective GC in horses are warranted. In this study, we used a full body network of wireless, high sampling-rate sensors combined with machine learning to fully automatically classify gait. Using data from 120 horses of four different domestic breeds, equipped with seven motion sensors, we included 7576 strides from eight different gaits. GC was trained using several machine-learning approaches, both from feature-extracted data and from raw sensor data. Our best GC model achieved 97% accuracy. Our technique facilitated accurate, GC that enables in-depth biomechanical studies and allows for highly accurate phenotyping of gait for genetic research and breeding. Our approach lends itself for potential use in other quadrupedal species without the need for developing gait/animal specific algorithms.

s of the 10th International Conference on Equine Exercise Physiology. Lorne, Australia, 12 - 16 November 2018.

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 forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain-related movement asymmetries is a prerequisite for successful lameness assessment. OBJECTIVES: To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. STUDY DESIGN: Experimental study. METHODS: In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three-dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range-up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. RESULTS: For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35-0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05-0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. MAIN LIMITATIONS: Results must be confirmed in clinically lame horses trotting overground. CONCLUSIONS: The vertical asymmetry pattern of the withers discriminated a head nod associated with true forelimb lameness from the compensatory head movement asymmetry cau

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 this movement to the movements of the horse and rider. Data from seven Warmblood dressage horses competing at Grand Prix (n = 6) or FEI Intermediate (n = 1) level, ridden by their usual riders, were used. Simultaneous kinetic, kinematic and saddle pressure measurements were conducted during sitting and rising trot on a force-measuring treadmill. The maximum lateral movement of the caudal part of the saddle relative to the horse's spine (MAX) was determined for each diagonal step. A mixed model was applied, with MAX as outcome, and T6 and S3 vertical position, rigid body rotation angles (roll, pitch, yaw) of the horse's and rider's pelvis, vertical ground reaction forces, saddle force, and rider position (rising in rising trot, sitting in rising trot or sitting in sitting trot) as explanatory variables. The least square means for MAX were 14.3 (SE 4.7) mm and 23.9 (SE 4.7) mm for rising and sitting in rising trot, and 20.3 (SE 4.7) mm for sitting trot. A 10 mm increase in maximum pelvic height at push off increased MAX by 1.4 mm (p<0.0001). One degree increase in rider pelvis roll decreased MAX 1.1 mm, and one degree increase in rider pelvis yaw increased MAX 0.7 mm (both p<0.0001). The linear relationships found between MAX and movements of both horse and rider implies that both horse and rider movement asymmetries are reflected in the lateral movements or oscillations of the saddle in non-lame horses.

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, unrestrained position (HNP1), more flexed positions (HNP3, HNP4), a raised extended position (HNP5) and a forward-downward extended position (HNP6). An experimental study in seven high-level dressage horses ridden at walk on a treadmill was designed. Kinetic and kinematic measurements were obtained with different HNPs. HNP2 was used as a speed-matched reference. Kinematics were measured from skin-fixed markers recorded by high-speed video cameras. The kinetics of the limbs were measured by the force-measuring instrumentation of the treadmill. In HNP1, compared to HNP2, the lumbar back and the pelvis were more horizontally positioned (more extended), and fore- and hindlimb pro- and retraction increased, with increased caudal rotation of the femur during the second half of hindlimb stance. HNP6 induced similar changes as HNP1, but caused larger increases in forelimb pro- and retraction. In HNP3, HNP4 and HNP5 the pelvis was more angled (less extended) compared to HNP2 at hindlimb midstance, and in HNP3 and HNP4 also in early hindlimb stance. All three HNPs caused increased maximum flexion of the tarsus, stifle and metatarsophalangeal joint during the swing phase. HNP3 and HNP5, but not HNP4, had a decreasing influence on fore- and hindlimb pro- and retraction, and decreased caudal rotation of the femur during the second half of hindlimb stance.The main limitation was that horses were not ridden overground and the number of horses was small. Our conclusion was that changes in head and neck position can markedly affect the horse’s movement pattern at walk.

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 forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain‐related movement asymmetries is a prerequisite for successful lameness assessment. Objectives To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. Study design Experimental study. Methods In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three‐dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range‐up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. Results For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35–0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05–0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. Main limitations Results must be confirmed in clinically lame horses trotting overground. Conclusions The vertical asymmetry pattern of the withers discriminated a head nod associated wi

BACKGROUND: Objective gait analysis is becoming more popular as a tool assisting veterinarians during the clinical lameness exam. At present, there is only limited information on the effect of misplacement of markers/motion-sensors. OBJECTIVES: To investigate and describe the effect of marker misplacement on commonly calculated pelvic symmetry parameters. STUDY DESIGN: Experimental study. METHODS: Each horse was equipped with custom-made devices consisting of several reflective markers arranged in a predefined manner with a reference marker correctly positioned regarding the anatomical landmark and several misplaced markers along the sagittal and transverse planes. Linear regression analysis was used to estimate the effect of marker misplacement. RESULTS: For the tubera sacrale, each cm of left/right misplacement led to a difference in minimum position of the pelvis (PDmin) of ±1.67 mm (95% CI 1.54-1.8 mm) (P<0.001); maximum position of the pelvis (PDmax) was affected by ±0.2 mm (95% CI 0.071-0.33 mm) (P = 0.003). With respect to cranial/caudal misplacement, each cm of misplacement resulted in a PDmin difference of ±0.04 mm (95% CI -0.09 to 0.16 mm) (P = 0.56) and a PDmax difference of ±0.008 mm (95% CI -0.13 to 0.12 mm) (P = 0.9). For the tubera coxae, each cm of vertical misplacement led to a difference in the displacement amplitude between left and right tubera coxae (Hip-Hike_Diff) of ±1.56 mm (95% CI 1.35-1.77 mm) (P<0.001); for the cranial/caudal misplacement, this was ±0.82 mm (95% CI 0.66-0.97 mm) (P<0.001). MAIN LIMITATIONS: Only three horses were used in this experiment and the study design did not permit to determine the influence of marker misplacement on the evaluation of different degrees of lameness. CONCLUSIONS: Marker misplacement significantly affects calculated symmetry parameters of the pelvis. The observed errors are overall small but significant. In cases of mildly asymmetrical horses, this error might influence the decision-making process wher

REASONS FOR PERFORMING STUDY: A comprehensive kinematic description of rider and saddle movements is not yet present in the scientific literature. OBJECTIVE: To describe saddle and rider movements in a group of high-level dressage horses and riders. METHOD: Seven high-level dressage horses and riders were subjected to kinematic measurements while performing collected trot on a treadmill. For analysis a rigid body model for the saddle and core rider segments, projection angles of the rider's extremities and the neck and trunk of the horse, and distances between markers selected to indicate rider position were used. RESULTS: For a majority of the variables measured it was possible to describe a common pattern for the group. Rotations around the transverse axis (pitch) were generally biphasic for each diagonal. During the first half of stance the saddle rotated anti-clockwise and the rider's pelvis clockwise viewed from the right and the rider's lumbar back extended. During the later part of stance and the suspension phase reverse pitch rotations were observed. Rotations of the saddle and core rider segments around the longitudinal (roll) and vertical axes (yaw) changed direction only around time of contact of each diagonal. CONCLUSION: The saddles and riders of high-level dressage horses follow a common movement pattern at collected trot. The movements of the saddle and rider are clearly related to the movements of the horse and saddle movements also seem to be influenced by the rider. POTENTIAL RELEVANCE: Knowledge about rider and saddle movements can further our understanding of, and hence possibilities to prevent, orthopaedic injuries related to the exposure of the horse to a rider and saddle.