Recipient Organization
COLORADO STATE UNIVERSITY
(N/A)
FORT COLLINS,CO 80523
Performing Department
Clinical Science
Non Technical Summary
It is well recognized that elite level human athletes suffer from low-grade pain, thought to be associated with cyclic, repetitive exercise. Despite this, human athletes are reported to perform successfully in the face of low-grade musculoskeletal pain. Elite equine athletes are also intensively trained and subject to repetitive exercise so it is not surprising that they also frequently present with low-grade musculoskeletal pain, corresponding to subtle lameness and/or gait abnormalities. Interestingly, the prevalence of low-grade musculoskeletal pain and its influence on functional (i.e. performance) outcomes, is not known. As caretakers of the equine athlete the equine sports medicine clinician must establish what is considered normal variation in asymmetry of gait relative to true injury so that management can be appropriately implemented. In order to accomplish this goal, the investigators aim to evaluate approximately 300 high-level equine athletes performing at an international championship competition in 6 different disciplines. The study horses will be actively compete under strict 'clean-sport' rules that prevent use of performance enhancing medications such as non-steroidal anti-inflammatory drugs. This ensures a more accurate assessment of the low grade pain that may be present in elite equine athletes. The authors hypothesize that the majority of horses competing at the international level will have subtle lameness and that while subtle lameness will not have a negative influence on competition results, more obvious lamenesses will negatively impact performance. The authors also hypothesize that outcomes of objectively scored disciplines will be less influenced by lameness than subjectively scored disciplines.
Animal Health Component
30%
Research Effort Categories
Basic
70%
Applied
30%
Developmental
0%
Goals / Objectives
Background and purpose:Musculoskeletal disease is the most frequent cause of poor performance in the equine athlete, resulting in lost days of training and competition. A proportion of days lost are likely due to pain associated with repetitive exercise or overuse, as reported in the human athlete. Regardless of discipline, horses that perform at an elite level are subject to intensive training and extensive repetition, in order to perfect discipline specific skills. It is therefore expected that, like human athletes, equine athletes suffer from pain associated with intensive and repetitive training. In humans it has been stated that to accurately assess this, functional outcomes rather than time lost from sports should be measured so that prevalence is not underestimated. In racehorses, correlation of musculoskeletal injury to performance has been extensively documented but this influence of musculoskeletal pain on functional outcome in other competitive equestrian disciplines has not been critically evaluated.Poor performance secondary to perceived low-grade musculoskeletal pain is a common presenting complaint in the equine athlete in full training. With this, increasing emphasis is placed on subtle or even 'sub-clinical' lameness, asymmetries of gait, and changes in execution of specific skills. Understanding what comprises a clinically normal horse in an intense training program, with respect to degree of gait asymmetry and/or ability to execute advanced skills, is therefore required. Establishing a threshold to differentiate functional soundness from lameness will aid equine practitioners in: avoiding potentially unwarranted diagnostics and treatments; recognizing a level of unsoundness that correlates to poor functional outcomes; and most importantly, identifying horses that may be injured versus horses with low-grade pain associated with normal training. It is also recognized, anecdotally, that 'will to win' may override subtle or low-grade pain associated with musculoskeletal disease in athletes, and cannot be easily quantified.Investigating the prevalence of lameness in a large population of equine athletes in competition, and correlating this with functional (competitive) outcomes to establish the influence of lameness on performance will provide an incomparable reference for clinicians when evaluating horses in full training for poor performance. It is expected that the majority of horses competing at an international level under rules of the international governing body (Federation Equestrian International- FEI) will have some degree of lameness present, but that subtle lameness will not directly impact performance, while more obvious lameness will negatively affect performance outcome. Further, degree of lameness is expected to have a greater influence on disciplines graded subjectively, than on those graded objectively.Hypotheses:The majority of horses competing at the FEI level, across disciplines, will have subtle lameness.Subtle lameness will not directly correlate to performance outcome.More obvious lameness (> grade 2 of 5) will negatively affect horses performance outcome.Outcomes of objectively scored disciplines will be less influenced by lameness than subjectively scored disciplines. Specific Aims: The hypotheses above will be tested by means of the following specific aims.1. To determine the prevalence of lameness in equine athletes competing in at the FEI level in various disciplines (Dressage, 3-day Eventing, Show Jumping, Reining, Endurance). All competitors entered at the multi-discipline North American Junior and Young Rider Championships 2018 will be invited to enroll in the study. Each horse will be subjectively evaluated for lameness (grade 0 to 5) by two experienced lameness clinicians following entry to the competition venue and prior to beginning of the competition. Within the same examination, an objective assessment of lameness will be performed by uniform application of an inertial sensor system (Equinosis Q with Lameness Locator®). Prevalence of lameness, categorized by severity, will be calculated within and across disciplines.2. To establish the impact of lameness on performance outcome in multiple equestrian disciplines and to compare between disciplines how lameness influences performance outcome with respect to subjective and objective performance parameters.Lameness evaluation will be performed as described above. Competition outcomes will be recorded as per the results of competition in each discipline. Subjective scores (e.g. based on judge's opinion) are provided in dressage, eventing dressage, and reining. Objective scores (e.g. from penalty points incurred while jumping or race completion time) are available from show jumping, the jumping phases of eventing, and endurance. Comparisons of final placing and degree of lameness will be made within each discipline. The correlation of lameness with placing will then be compared between disciplines to establish if the scoring method is sensitive to the degree of lameness.
Project Methods
All competitors entering the North American Junior and Young Rider Championships (NAJYRC) 2018 will be invited to enroll in the study. This annual event, run by the United States Equestrian Federation (USEF), includes championship competitions in the Olympic disciplines of dressage, show jumping, 3-day eventing, endurance, para-dressage and reining. Competitors hail from across the United States, Mexico and Canada and approximately 300 experienced high-level equine athletes are expected to participate. The premise of the study has been discussed with the USEF NAJYRC coordinator, who expressed his enthusiasm to help carry out the study. Upon event entry, an information document will be sent to every competitor to familiarize them with the study concept prior to arrival at the event. Each competitor enrolling in the study will be asked to complete a simple, uniform questionnaire regarding management of their horse prior to and during the event, and for historical musculoskeletal injuries, disease and treatment. All competitors at the NAJYRC must abide by the FEI clean sport rules, which prohibits administration of performance enhancing substances during the event, thus ensuring that no bias is introduced by administration of anti-inflammatory or performance enhancing medications. All horses are assessed on arrival for general health and are stabled routinely within the same venue.Per FEI rules, the day prior to the start of competition, each horse is presented to the official FEI veterinarian for lameness evaluation to ensure that no overtly lame horses are allowed to compete, providing a large population of sound or subtly lame horses, as required by the study design. On the same day, the study investigators will also examine all enrolled horses. Each horse will be evaluated for general health with a brief physical examination (e.g. auscultation of the heart and lungs, temperature, hydration status) to ensure no systemic confounding factors exist; if found, the horse will be excluded from the study. The horse will then be instrumented with the inertial sensor system as recommended. The system consists of a uniaxial accelerometer attached to the headpiece of the halter by a secure bonnet, a uniaxial accelerometer placed between the tuber sacrale and held in place with Velcro tape, and a uniaxial gyroscope secured to the right front pastern with a neoprene wrap. A simultaneous objective (inertial sensor system data collection) and subjective (blinded observations by two experienced lameness clinicians) lameness evaluation will then be performed by trotting the horse, in hand over a straight surface distance of 50m for a total of 200m of observation (e.g. 4 x 50m distance). Results for each horse will be released only to the competitor upon request, but otherwise will be completely confidential.Data acquired from the inertial sensor system includes difference in head position (maximum and minimum), difference in pelvic position (maximum and minimum) and a vector sum. Overall objective analysis captures asymmetry of gait as a value of the vector sum for the front limbs and for the hind limbs. Data collected from the subjective evaluation of lameness will provide a grade (0-5) for each limb based on a well-established lameness scale (AAEP grading scale). Overall results will be obtained at the end of the competition from each competitive discipline.Data will be analyzed by means of a Spearman's Rank correlation coefficient performed to determine the correlation between results score and lameness grade for each discipline, the correlation between subjective and objective lameness scores, and to determine if discipline influences the correlation between lameness and results score.