Spatial variation of the physical and biomechanical properties within an equestrian arena surface

There is limited information about spatial variation of equestrian arena surfaces despite unequivocal evidence to suggest that lack of uniformity increases risk of injury. Spatial differences in the functional properties of an arena are likely to be due to a number of intrinsic and extrinsic characteristics including variation in the physical properties of the surface. The aim of this work was to examine spatial variation of peak load (cushioning) across an arena surface and investigate the influence that physical properties had on these variations using Principal Component Analysis. Sampling (n=61) of a 20 m by 65 m indoor synthetic equestrian arena surface occurred in one day using an Orono biomechanical surface tester (OBST). The OBST was used at every location to measure peak load (dropped twice on the same point). A 200 g sample of the surface was taken from the point of impact (at every location) and the physical properties were assessed in the laboratory. Samples were oven dried at 45⁰C for 24 hours in order to measure moisture content and percentage binder was quantified using Soxhlet extraction. Sand particle size distribution were determined using sieving and sedimentation methods and percentage organic matter was achieved by burning off organic material using a muffle furnace at 440⁰C. The surface was characterized by three principal components (PC1, PC2 and PC3). Peak load and moisture were the first principal components that accounted for 41% of surface variation. Percentage organic matter and percentage binder were identified as PC2 (20%) and PC3 (18%) respectively. This highlights their respective importance in surface variation. There was a moderate negative correlation between moisture and peak load (rs = 54%; P<0.0001) however cluster analysis revealed that peak load and moisture were grouped into five areas of similarity that corresponded to sample location, reinforced using an ANOVA (P<0.0001). The findings demonstrate an effective method of assessing uniformity and additionally, identify physical factors relevant to the load carrying capacity of this specific surface. Uneven surfaces can influence horse and rider safety therefore recognizing appropriate techniques to monitor spatial variation and implement relevant maintenance, is of key importance to equestrian athletes

Equine Surfaces White Paper

This white paper has been drafted as a collection of published scientific papers and data. It is considered a work in progress and will be updated as new scientific studies and surface data become availabl

Comparison of equipment used to measure shear properties in equine arena surfaces

The design of a novel apparatus, the Glen Withy torque tester (GWTT), for measuring horizontal shear properties in equine sport surfaces is described. Previous research has considered the effect of vertical loading on equine performance and injury but only limited discussion has concerned the grip or horizontal motion of the hoof. The horizontal support of the hoof by the surface must be sufficient to avoid excess slip without overloading the limb. The GWTT measures the torque necessary to twist an artificial hoof that is being pushed into the surface under a consistently applied vertical load. Its output was validated using a steel surface, then was used to test two sand and fibre surfaces (waxed and non-waxed) through rotations of 40–140°, and vertical loads of 157–1138 N. An Orono biomechanical surface tester (OBST) measured longitudinal shear and vertical force, whilst a traction tester measured rotational shear after being dropped onto the surfaces. A weak, but significant, linear relationship was found between rotational shear measured using the GWTT and longitudinal shear quantified using the OBST. However, only the GWTT was able to detect significant differences in shear resistance between the surfaces. Future work should continue to investigate the strain rate and non-linear load response of surfaces used in equestrian sports. Measurements should be closely tied to horse biomechanics and should include information on the maintenance condition and surface composition. Both the GWTT and the OBST are necessary to adequately characterise all the important functional properties of equine sport surfaces

The Development of a Standardized Protocol for Quantifying Equestrian Eventing Cross-Country Ground

The ground has long been cited as a key contributing factor for injury risk in the cross-country phase of eventing. The current study aimed to develop a practically useful standardized protocol for measuring eventing cross country ground. Data collection was split into three phases: Phase 1 (Validation), Phase 2 (Expansion of data set), and Phase 3 (Threshold establishment). During Phase 1, data from nine event courses were collected using an Orono Biomechanical Surface Tester (OBST), Vienna Surface Tester (VST), Lang Penetrometer, Going Stick, and moisture meter. Using linear regression, 80% of the variability in cushioning measured with the OBST was predicted from moisture and VST measurements (p < 0.001). In Phase 2, objective data from 81 event courses and subjective assessments from 180 event riders were collected. In Phase 3, k-means cluster analysis was used to classify the courses into ten clusters based on average course measurements of moisture, cushioning, firmness, stiffness, depth, and coefficient of restitution. Based on cluster membership, course average subjective data (16 courses) were compared using a General Linear Model. Significant differences (p < 0.05) in subjective impact firmness (p = 0.038) and subjective cushioning (p = 0.010) were found between clusters. These data and cluster thresholds provide an event course baseline for future comparisons

Detection of subtelomere imbalance using MLPA: validation, development of an analysis protocol, and application in a diagnostic centre

BACKGROUND: Commercial MLPA kits (MRC-Holland) are available for detecting imbalance at the subtelomere regions of chromosomes; each kit consists of one probe for each subtelomere. METHODS: For validation of the kits, 208 patients were tested, of which 128 were known to be abnormal, corresponding to 8528 genomic regions overall. Validation samples included those with trisomy 13, 18 and 21, microscopically visible terminal deletions and duplications, sex chromosome abnormalities and submicroscopic abnormalities identified by multiprobe FISH. A robust and sensitive analysis system was developed to allow accurate interpretation of single probe results, which is essential as breakpoints may occur between MLPA probes. RESULTS: The validation results showed that MLPA is a highly efficient technique for medium-throughput screening for subtelomere imbalance, with 95% confidence intervals for positive and negative predictive accuracies of 0.951-0.996 and 0.9996-1 respectively. A diagnostic testing strategy was established for subtelomere MLPA and any subsequent follow-up tests that may be required. The efficacy of this approach was demonstrated during 15 months of diagnostic testing when 455 patients were tested and 27 (5.9%) abnormal cases were detected. CONCLUSION: The development of a robust, medium-throughput analysis system for the interpretation of results from subtelomere assays will be of benefit to other Centres wishing to implement such an MLPA-based service

The scene of the crime: inventing the serial killer

This article examines the meanings of the crime scene in serial killings, and the tensions between the real and the imagined in the circulation of those meanings. Starting with the Whitechapel Murders of 1888 it argues that they, as well as forming an origin for the construction of the identity of 'the serial killer', initiate certain ideas about the relationship of subjects to spaces and the existence of the self in the modern urban landscape. It suggests that these ideas come to play an integral part in the contemporary discourse of serial killing, both in the popular imagination and in professional analysis. Examining the Whitechapel Murders, more recent cases and modern profiling techniques, it argues that popular and professional representations of crime scenes reveal more of social anxieties about the nature of the public and the private than they do about serial killers. It suggests that 'the serial killer' is not a coherent type, but an invention produced from the confusions of persons and places. Copyright 2006 SAGE Publications. All rights reserved. Not for commercial use or unauthorized distribution

The challenges of equestrian arena surfaces: the unprecedented use of a raised platform at the 2012 Olympic Games

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 i) the Olympic test-event; ii) a developmental mock-up arena and iii) 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 initiative

The development of a standardized protocol for quantifying eventing cross-country ground

The ground has long been cited as a key contributing factor for injury risk in the cross-country phase of eventing. The current study aimed to develop a practically useful standardized protocol for measuring eventing cross country ground. Data collection was split into three phases: Phase 1 (Validation), Phase 2 (Expansion of data set), and Phase 3 (Threshold establishment). During Phase 1, data from nine event courses were collected using an Orono Biomechanical Surface Tester (OBST), Vienna Surface Tester (VST), Lang Penetrometer, Going Stick, and moisture meter. Using linear regression, 80% of the variability in cushioning measured with the OBST was predicted from moisture and VST measurements (p < 0.001). In Phase 2, objective data from 81 event courses and subjective assessments from 180 event riders were collected. In Phase 3, k-means cluster analysis was used to classify the courses into ten clusters based on average course measurements of moisture, cushioning, firmness, stiffness, depth, and coefficient of restitution. Based on cluster membership, course average subjective data (16 courses) were compared using a General Linear Model. Significant differences (p < 0.05) in subjective impact firmness (p = 0.038) and subjective cushioning (p = 0.010) were found between clusters. These data and cluster thresholds provide an event course baseline for future comparisons