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 capture. Stride-segmented pelvic roll data, normalised with respect to time (0-100% of the stride) and amplitude (± 0.5 of horse average stride range of motion), were modelled as a linear combination of sine and cosine curves. A sine curve with one period per stride and a cosine curve with three periods per stride explained the largest proportions of roll motion: model estimate 0.335 (p < 0.01) and 0.138 (p < 0.01), respectively. Using finite mixture models, the horses could be separated into three groups sharing common pelvic roll characteristics. In conclusion, pelvic roll motion in trot follows a similar basic pattern in most horses, yet there is significant individual variation in the relative prominence of the most characteristic features.

Guidelines for the Measurement of Rein Tension in Equestrian Sport

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 reporting of rein tension data. The goal is to assist users in selecting appropriate equipment, choosing verified methods of calibration, data collection and analysis, and reporting their results consistently to facilitate comparisons between different studies. Sensors should have a suitable range and resolution together with a fast enough dynamic response, according to the gait, speed and type of riding for which they will be used. An appropriate calibration procedure is necessary before each recording session. A recording frequency of 50 Hz is adequate for most rein tension studies. The data may be analyzed using time-series methods or by extracting and analyzing discrete variables chosen in accordance with the study objectives. Consistent reporting facilitates comparisons between studies.

Bit type exerts an influence on self-controlled rein tension in unridden horses

Bit configuration and acting rein forces play a crucial role in oral health and comfort of ridden horses. Although it is a big animal welfare issue, dynamic response of horses to different bits has yet not been thoroughly investigated. This convenience sample experimental study describes a model to overcome the almost uncontrollable influence of riders on rein tension and evaluates self-controlled maximum side rein tension of ten sound horses randomly bitted with a double-jointed (DJS) and a version of a Mullen mouth snaffle-bit under unridden conditions. Horses were exercised at walk and trot on a horizontal treadmill wearing custom made force-sensing resistors (FSR) equipped to side reins. FSR were synchronized with a camera-based motion analysis system providing information on amplitudes and temporal occurrence of self-controlled maximum side rein tensile forces during different phases of separated motion cycles. The DJS exhibited larger side rein tension, indicating higher bit contact. Constant temporal occurrence of monophasic maxima at walk and biphasic maxima at trot could be observed in both bits. Within the limitations of this study, application of FSR linked to side reins in unridden horses may provide a promising tool when studying subjective response of horses to different bits.

Evaluation of Dynamic Structural Disorders in the Upper Airways and Applied Rein Tension in Healthy Dressage Horses During Riding in Different Gaits and Head-Neck Positions

Flexion of the horse's head and neck during dressage riding reduces the pharyngeal lumen with the risk of increased upper airway resistance and upper airway obstructions. According to the Fédération Equestre Internationale, hyperflexion is achieved through force, whereas the position low-deep-round is nonforced. The objectives of this study were to evaluate (1) applied rein tension and (2) dynamic structural disorders in the upper airways in dressage horses in different gaits and different head-neck positions (HNPs). Overground endoscopy (OGE) and rein tension were evaluated in 13 clinically healthy and high-performance Warmblood dressage horses while being ridden in a standardized program comprised of four different gaits (halt, walk, trot, and canter) and in four HNPs (unrestrained, competition frame, hyperflexion, and low-deep-round). All included horses were able to achieve the desired HNPs. The HNP low-deep-round showed significantly lower rein tension than competition frame (P < .001) and hyperflexion (P < .001). An association was found between dynamic structural disorders in the upper airway tract evaluated by OGE and head-neck flexion, but this association was not linked to the degree of flexion. The HNP hyperflexion was neither associated with greater rein tension nor severe dynamic structural disorders than the HNP competition frame. This study confirms that low-deep-round is a nonforced position, in contrast to hyperflexion. Further studies are needed to evaluate whether dynamic structural disorders are a result of flexion or if the degree of flexion has an impact.

Rein Tension in Transitions and Halts during Equestrian Dressage Training

Simple Summary

In the equestrian dressage discipline, the transitions (changes) between gaits and into halts, occur often in riding sessions. Rein tension before, during and after the transitions between gaits, and the transitions into halts were studied. The vertical motion data for the horse’s head and croup, and rein tension data were collected from six professional riders, each riding three of their own horses during normal training sessions. The horse training levels varied from basic to advanced. The activities during the sessions were categorised into gaits, transitions between gaits and into halts based on video evaluation. The transitions were categorised according to whether they had intermediate steps that were not characteristic of the preceding or the following gait. The rein tension just before the transition was strongly related to rein tension during the transitions. There was slightly lower tension during the upward transitions than during the downward transitions. There was no difference in rein tension depending on whether intermediate steps were present or not. The left rein tension was generally lower than the right rein tension. The rein tension associated with the transitions and halts varied substantially between riders and also the horses. This information is useful for trainers seeking to understand the rein tension patterns associated with transitions.

Abstract

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 collected (128 Hz) from six professional riders each riding three of their own horses, training levels varying from basic to advanced, during normal training sessions. The activities were categorised into gaits, halts and transitions based on video evaluation. The transitions were categorised as without (type 1) or with (type 2) intermediate steps that are not normally present in the gaits preceding or following the transition. The differences in the median rein tension before/during/after transitions, between the types and left/right reins were analysed in mixed models. The rein tension just before the transition was the strongest determinant of tension during the transition. The rein tension was slightly lower during upward transitions compared to downward transitions, reflecting the pattern of the preceding gait. Type 1 and 2 downward transitions were not different regarding rein tension. The left rein tension was lower than right rein tension. The rein tension associated with the transitions and halts varied substantially between riders and horses. The generally strong association of the gaits and their inherent biomechanics with rein tension should be taken into account when riding transitions and halts.