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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, free position; HNP2, dressage competition position; HNP3, flexed poll position; HNP4, over-flexed position; HNP5, extended raised position; and HNP6, forward downward position. Kinematic and vertical ground reaction force data were recorded during 15 s trials on an instrumented treadmill. In mixed models, difference in the minimal height of the withers in early left vs right forelimb stance was modelled as dependent variable. The more restricted HNP3 (T-values 2.62 to 1.98, 118 DF, P = 0.001 to <0.05) and HNP5 (P = 0.002 to <0.05) were generally less symmetrical while unridden and more symmetrical while ridden, compared with the free (HNP1) or forward downward (HNP6) positions. Both with and without rider, when the withers dropped lower in early stance of one forelimb, this was associated with shorter protraction at the start of stance in the ipsilateral hind limb, and shorter stance overlaps between this hind limb and the other limbs during diagonal support, 3-limb support with two forelimbs and one hind limb, and ipsilateral support. HNP effects on withers movement asymmetry differed between unridden and ridden conditions. The considerable variation between horses stresses the need for trainers to use individualized training programs to address horse asymmetry. [ABSTRACT FROM AUTHOR]

Asymmetric forces exerted on the horse's back during riding are assumed to have a negative effect on rider–horse interaction, athletic performance, and health of the horse. Visualized on a saddle pressure mat, they are initially blamed on a nonfitting saddle. The contribution of horse and rider to an asymmetric loading pattern, however, is not well understood. The aim of this study was to investigate the effects of horse and rider asymmetries during stance and in sitting trot on the force distribution on the horse's back using a saddle pressure mat and motion capture analysis simultaneously. Data of 80 horse–rider pairs (HRP) were collected and analyzed using linear (mixed) models to determine the influence of rider and horse variables on asymmetric force distribution. Results showed high variation between HRP. Both rider and horse variables revealed significant relationships to asymmetric saddle force distribution (P <.001). During sitting trot, the collapse of the rider in one hip increased the force on the contralateral side, and the tilt of the rider's upper body to one side led to more force on the same side of the pressure mat. Analyzing different subsets of data revealed that rider posture as well as horse movements and conformation can cause an asymmetric force distribution. Because neither horse nor rider movement can be assessed independently during riding, the interpretation of an asymmetric force distribution on the saddle pressure mat remains challenging, and all contributing factors (horse, rider, saddle) need to be considered. • Horse, rider, and saddles can cause an asymmetric saddle pressure measurement. • Collapse in one hip and tilt to one side are important rider variables. • Collapse in one hip increases saddle pressure on the contralateral side. • Tilt of the rider to one side increases saddle pressure on the same side. • Horse movements and conformation are important horse variables. [ABSTRACT FROM AUTHOR]

Equestrians use reins to communicate with the horse. The aim of this study was to describe the amplitudes of rein tension oscillations at canter. Rein tension data were collected from 8 professional riders each riding 2-3 horses during a normal dressage training session using rein tension meters (128 Hz, logged by an inertial measurement unit sensor). Data were stride-split at the maximal positive vertical poll acceleration. Strides were categorized by canter lead, rider position (sitting/2 point), corners, circles, lateral movements, and stride length (collected/working/lengthened). Changes in head angle were determined from gyroscopic sensor data. Dependent data extracted from each stride and rein were maximal tension (MAX), minimal tension (MIN), and the absolute difference between them (CHANGE). Square-root transformed data were analyzed using mixed models with stride categorizations as fixed effects, and rider and horse included as random effects. Findings for rein tension were considered borderline if 0.05< P >0.001, but significant if P < 0.001. For the rider's position, the magnitudes were higher in sitting canter than 2-point seat ( P < 0.0001), except for inside rein MIN value (n = 21,548 strides). For MAX (both reins), MIN (inside), and CHANGE (outside), the right circle had lower values than the left circle or no circle. For the outside rein, MAX and MIN values showed borderline differences with higher values for lengthened strides than working canter ( P = 0.03/0.0014). Inside rein values in right half pass were significantly or borderline higher than left half pass or baseline, and for MIN values, this was found for both inside/outside reins. Both group effects and all pairwise comparisons evaluated were significant for MAX and CHANGE, except the comparison between inside and outside rein in right canter. MAX/MIN tensions were higher if the nose was moving caudally relative to poll at the MAX/MIN event, respectively. Young horses had the largest MAX and CHANGE values, whereas advanced horses had the highest MIN values. The horse contributed 7%, 27%, and 29% of the variation to MIN, MAX, and CHANGE models, respectively. The rider contributed 19% of the variation to the MIN value models but 0% to the MAX and CHANGE models, suggesting that the horse or the dyad (not statistically separable) is responsible for the basic rein tension pattern at canter. Overall results indicate that asymmetry, of riders and/or horses, plays a role in rein tension. [ABSTRACT FROM AUTHOR]

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 for riders and horses within riders, the between-rein variation, and the general within-gait or exercise variation, during entire riding sessions. Eight riders with 3 horses each were included in the study and each horse was fitted with a custom-made rein tension meter fastened on leather reins. Rein tension data and video films were collected during the riding session, and the video films were scrutinized and categorized according to ridden exercises. Statistics used to model rein tension in mixed models were “median”, area under curve, averages of 2 and 25 percentiles (“low”) and of 75 and 98 percentiles (“high”), and the difference between 98 and 2 percentiles (“range”). Fixed effects were rein, gait, rider's position, horse level, and type of ridden exercise, and random effects were horse-side, rider, horse, and trial within horse. The analyses demonstrate substantial variation between gaits, rider position within gait, and between riders and horses. Considering data on short reins, the major determinants found for amount of rein tension was gait (walk [median 12 N both reins]

Anecdotally, orofacial pain patients sometimes report that the painful face area feels “swollen.” Because there are no clinical signs of swelling, such illusions may represent perceptual distortions. In this study, we examine whether nociceptive stimulation can lead to perceptual distortion of the face in a way similar to that of local anesthesia. Sixteen healthy participants received injections of .4 mL hypertonic saline to induce short-term nociceptive stimulation, .4 mL mepivacaine (local anesthetic) to transiently block nerve transduction, and .4 mL isotonic saline as a control condition. Injections were administered in both the infraorbital and the mental nerve regions. Perceptual distortions were conceptualized as perceived changes in magnitude of the injected areas and the lips, and they were measured using 1) a verbal subjective rating scale and 2) a warping procedure. Prior to the study, participants filled in several psychological questionnaires. This study shows that both nociceptive stimulation ( P < .05) and transient blocking of nerve transduction ( P < .05) can lead to perceptual distortion of the face. A test-retest experiment including 9 new healthy subjects supported the results. Perceptual distortions were positively correlated with the psychological variable of dissociation in several conditions ( P < .05). Perceptual distortions may therefore be influenced by somatosensory changes and psychological mechanisms. Perspective Knowledge of the factors that influence the perception of the face is important to understand the possible implications of perceptual distortions in orofacial pain disorders (and possibly other chronic pain states). Such information may ultimately open up new avenues of treatment for persistent orofacial pain. [ABSTRACT FROM AUTHOR]

• Quantitative gait analysis offers objective and unbiased gait information that can assist during lameness examination. • There is a considerable impact of chosen filtering method on the calculated parameters used for objective lameness assessment. • IIR Butterworth filter and the signal decomposition method achieved the best filtering results. Quantitative gait analysis in horses is rapidly gaining importance, both clinically and in research. The number of available systems is increasing, but the methods of signal analysis differ between systems and research groups. Our objectives are to describe and evaluate the effects of different methods of signal analysis for processing of data from equine kinematic gait analysis. To this end, we use theoretical signals based on previously published work, followed by the evaluation of the performance of each technique using real data from horses with induced lameness. Two infinite impulse response (IIR), high-pass filters (Butterworth and Chebyshev), a signal decomposition method and a moving average filtering technique were evaluated. First, we describe methods to fine-tune each filter to the optimal settings based on residual analysis. Second the performance of each filter is evaluated based on differences in calculated symmetry parameters from horses with induced lameness. We show that optimisation of filtering techniques is crucial when processing signals used for objective lameness quantification. Improper selection of the cut-off frequency for IIR filters can result in false negative results (average values above or below predefined reference values). The IIR Butterworth filter and the signal decomposition method achieved the best reduction of unwanted signal components. Knowledge of the available filtering techniques is a pre-requisite for adequate signal processing of gait data from quantitative analysis systems in horses. [ABSTRACT FROM AUTHOR]

Abstract: According to the principles of negative reinforcement, when an aid has been given to an animal, it should be released as soon as the desired response has been achieved, and, if performed well, may be associated with fewer conflict behaviors than otherwise. In riding, pressure in the horse’s mouth from the bit is used to give signals to the horse, and both rein tension and patterns of releasing this tension will vary. The aim of this pilot study was to study horse behavior during 2 different methodologies used to shape relatively naïve horses to a deceleration signal while making downward transitions from trot to walk. Method 1 involved relief from rein tension at the first attempt to perform a correct response (M1), and method 2 entailed that rein tension was relieved at the completed correct response (M2). Four horses were ridden by 4 riders over 4 days (1 rider each day), and each horse made 10 transitions each day for each method, which produced 320 transitions. Rein tension was recorded, and horse behavior and rider signal behaviors were evaluated from video recordings. Horse behavior was divided into the following 3 different categories: “pushing against the bit,” “moving away from the bit,” and “decelerating.” Linear models were constructed tracking the percent of the transition time that horses demonstrated at least 1 behavior in the “pushing against the bit,” “moving away from the bit,” and “decelerating” categories, and with random effects for rider, horse, and transition number nested within horse. Fixed effects analyzed were the methods, proportion of the transition time above 30 N for each rein, and the rider signal behaviors. M1 and M2 had on average 19% (standard deviation: 16) and 38% (standard deviation: 23) of the time with >30 N per rein, respectively. In the models for the “pushing against the bit” behaviors, M2 increased rein tension and “exerting pressure on the reins” increased the level of these behaviors. “Releasing pressure” interacted with “pulling back on the reins”; this combination was associated with an increased level of “pushing against the bit” behaviors. The “decelerating” behavior was associated with lower rein tension. In the “decelerating” behavior models, “pulling back on the reins” led to decreased “decelerating” behavior, whereas “still hand” and “releasing pressure” led to increased “decelerating” behavior; however, the interaction “pulling back on the reins” and “releasing pressure” led to decreased “decelerating” behavior. “Moving away from the bit” had no significant determinants. We concluded that fewer “pushing against the bit” behaviors were created by M1 and that a lower rein tension was associated with the “decelerating” behavior. Reinforcing the horse’s attempts, to assist in finding the correct response, benefits the welfare of the horse, and importance of a light hand should be continuously emphasized during riding education. [Copyright &y& Elsevier]

To identify myofibrillar substrates of μ-calpain under post-mortem conditions, a combination of SDS–PAGE, two-dimensional gel electrophoresis (2DE) and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) was used. Purified myofibrils were incubated with μ-calpain under post-mortem-simulated conditions for two or four days at 4 °C. The resulting protein changes were analyzed by SDS–PAGE and 2DE. The μ-calpain-mediated protein changes were identified by peptide-mass mapping using MALDI-TOF MS and revealed that desmin, actin, myosin heavy chain, myosin light chain I, troponin T, tropomyosin α1, tropomyosin α4, thioredoxin and CapZ are all degraded in vitro by μ-calpain. The findings that actin and myosin heavy chain are substrates of μ-calpain were rather surprising, as it has previously been reported that these proteins are resistant to μ-calpain degradation. However, both actin and myosin heavy chain are poor substrates compared with desmin. [Copyright &y& Elsevier]

• Surface assessment supported development of a high-profile temporary equine arena. • Arena construction on a raised platform revealed the importance of the base-layer. • Modifications in base-layer stiffness were identified by differences in peak load. • Time since installation is a key factor in performance of temporary equine arenas. The design of equestrian arenas can be challenged by time constraints and specific restrictions at a venue but are nonetheless a critical element to the success and sustainability of equestrian sport. The equestrian arenas for the 2012 Olympic Games were an example of a temporary arena constructed on a raised platform and supported by struts, a design unprecedented for equestrian activities. This study assessed the developmental stages of the Olympic surfaces from 2011 to the actual event in 2012 and aimed to confirm that accelerations and forces experienced by horses were comparable to those on solid ground. Assessment took place at (1) the Olympic test event;(2) a developmental mock-up arena; and (3) the Olympic venue in 2012. A Clegg impact hammer measured peak vertical deceleration and an Orono Biomechanical Surface Tester quantified peak load and peak loading rate. General Linear Models using the arena's structural features as explanatory variables highlighted surface heterogeneity. Peak vertical deceleration (P <.0001) and peak load (P <.0001) were significantly higher and peak loading rate was significantly lower (P <.0001) following iterative testing and modifications to the arena. Data were comparable with surfaces on solid ground by the final testing at the 2012 Olympic Games. Findings highlighted the importance of testing surfaces throughout their development and demonstrated the impact that surface composition, time elapsed since installation, water management, and type of construction have on surface functional properties, with relevance to future temporary arena initiatives. [ABSTRACT FROM AUTHOR]

• At walk pelvic pitch differed between riders in amplitude and timing. • Pelvic pitching was in-phase or in counter-phase with pitching of the horse's trunk. • Pitching frequency was equal to or more frequent than the horse's step frequency. • The rider's pelvis had a single roll cycle per stride in-phase with the horse's trunk. 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. Each trial included each of the three walk variations in both directions. Riders wore an inertial measurement unit (IMU), logging at 100 Hz, dorsally on the pelvis. Pelvic roll and pitch data were split into strides based on data from IMU-sensors on the horse's hind cannons. Data were analyzed using signal decomposition into the fundamental frequency (the stride frequency) and its first two harmonics. Mixed models accounting for the type of walk were used to analyze how riders differed in roll and pitch pelvic motion in two ways: comparing amplitudes of the frequency components and comparing whole stride mean data. Graphically pelvic pitch showed substantial timing and amplitude differences between riders, and this was confirmed statistically. Pelvic roll timing was similar, but amplitude varied between the riders, both graphically and statistically. Individual rider patterns tended to persist across different horses and all exercises. These results suggest that exercises at walk can be ridden with different pelvis pitch timing, a fact that has so far not been discussed in the equestrian literature. Whether pelvic pitch timing affects the horse's performance remains to be investigated. [ABSTRACT FROM AUTHOR]

Lameness is a symptom indicative of pain or injury of the locomotor apparatus. Lame horses generally should not be ridden. However, owners' ability to assess lameness has been questioned. This study's aim was to use subjective lameness assessments and objective gait analysis to generate a descriptive overview of movement and weight-bearing asymmetries of owner-sound riding horses. 235 horses were subjectively assessed in a field study, and the owner's perception of their horse's orthopedic health was recorded through an online survey. 69 horses were re-evaluated by gait analysis at an equine hospital. During trot on an instrumented treadmill, the gait was scored by a veterinarian using lameness grades from 0/5 (sound) to 3/5 (moderate lameness visible at trot). Movement asymmetry of the head (HDmin) and pelvis (PDmin) and weight-bearing asymmetry were quantified simultaneously. The prevalence of subjectively scored lameness grade ≥2/5 in one or more limbs was 55% during study part 1 and 74% during study part 2. Movement asymmetry of the head and/or pelvis exceeding HDmin ≥12 mm and/or PDmin ≥6 mm was found in 57% of the horses. 58% showed weight-bearing asymmetries between contralateral front and/or hind limbs of ≥3% body mass. Gait analysis showed considerable variability of movement and weight-bearing asymmetry values, sometimes independent of the clinical lameness grade, especially in the forehand. Several horses with lameness grade ≤1/5 had asymmetry values greater than mentioned thresholds. The analysis of movement and weight-bearing asymmetry revealed that these objective variables did not necessarily act uniformly and therefore should be interpreted with caution. • High occurrence of mild to moderate lameness scores in owner-sound horses. • Owner's perception of their horse's soundness was incongruent with veterinary examination. • Moderate agreement and positive correlation of subjective with objective methods. • In certain cases, objective asymmetry variables were independent of the clinical lameness grade. [ABSTRACT FROM AUTHOR]

Background: Parasitic helminth infections can protect against allergic airway inflammation in experimental models and have been associated with a reduced risk of atopy and a reduced course of asthma in some observational studies. Although no clinical evidence exists to support the use of helminth therapy for allergic disease, the helminth Trichuris suis has demonstrated efficacy in treatment of inflammatory bowel disease. Objective: To determine efficacy of helminth therapy for allergic rhinitis. Methods: We conducted a double-blind, placebo-controlled, parallel group trial in which 100 subjects age 18 to 65 years with grass pollen–induced allergic rhinitis were randomly assigned to ingest a total of 8 doses with 2500 live T suis ova or placebo with an interval of 21 days. The primary outcome was a change in mean daily total symptom score for runny, itchy, sneezing nose (maximum change, 9.0) or in percentage of well days during the grass pollen season. Results: Treatment with T suis ova (N = 49) compared with placebo (N = 47) caused transient diarrhea peaking at day 41 in 33% of participants (placebo, 2%), and increased eosinophil counts (P < .001) and T suis–specific IgE (P < .05), IgG (P < .001), IgG4 (P < .003), and IgA (P < .001), whereas there was no significant change in symptom scores (0.0; 95% CI, –0.5 to 0.4; P = .87), well days (3%; 95% CI, –9% to 14%; P = .63), total histamine (P = .44), grass-specific IgE (P = .76), or diameter of wheal reaction on skin prick testing with grass (P = .85) or 9 other allergens. Conclusion: Repeated treatment with the helminth T suis induced a substantial clinical and immunologic response as evidence of infection, but had no therapeutic effect on allergic rhinitis. [Copyright &y& Elsevier]