The development of safety and quality standards for equestrian surfaces needs to be based on objective, repeatable measurements which allow comparisons between surfaces. These measurements should incorporate the assessment of surface performance by riders. This study provides data from objective and subjective assessment of functional properties of high-level show jumping competition and warm-up arenas. Twenty-five arenas in nine international show jumping events were evaluated by mechanical in-situ testing with a surface tester, rider assessments using visual analogue scales (198 riders provided 749 arena evaluations), descriptions of arena constructions and by laboratory tests of surface material. Mixed models were used to present subjective evaluation of rider perception of the functional properties for each arena while controlling for rider and event. The association between objective and subjective assessments were also explored creating mixed models, controlling for rider and event. Mechanical measurements of impact firmness, and to a lesser extent cushioning and grip, had a significant positive association with the riders' perception. Responsiveness as assessed by the Orono biomechanical surface tester (OBST) was negatively associated with the riders' perceptions, which suggests riders and the OBST had different concepts of this functional property and that further developments of the OBST might be necessary. Objectively measured uniformity showed no useful association with riders' perception. Even though arena assessments were made by top level riders, a substantial inter-rider variation was demonstrated.

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1The design of a novel apparatus, the Glen Withy torque tester (GWTT), for measuring 2 horizontal shear properties in equine sport surfaces is described. Previous research has 3 considered the effect of vertical loading on equine performance and injury but only limited 4 discussion has concerned the grip or horizontal motion of the hoof. The horizontal support of 5 the hoof by the surface must be sufficient to avoid excess slip without overloading the limb. 6The GWTT measures the torque necessary to twist an artificial hoof that is being pushed into 7 the surface under a consistently applied vertical load. Its output was validated using a steel 8 surface, then was used to test two sand and fibre surfaces (waxed and non-waxed) through 9 rotations of 40-140°, and vertical loads of 156-980 N. An Orono biomechanical surface 10 tester (OBST) measured longitudinal shear and vertical force, whilst a traction tester 11 measured rotational shear after being dropped onto the surfaces. A weak, but significant, 12 linear relationship was found between rotational shear measured using the GWTT and 13 longitudinal shear quantified using the OBST. However, only the GWTT was able to detect 14 significant differences in shear resistance between the surfaces.

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There is a strong allometric relationship between stem diameter at breast height (DBH) and crown diameter in healthy trees in the young to mature stages of their growth. How do geographical position, site conditions and management treatments influence this relationship? This study included only free-standing urban trees, thus providing data on the growth potential of the species included in the survey in typical urban conditions by linking this with estimated tree age. Field work involved recording the dimensions and growing conditions of 400 urban trees in two UK cities; Norwich and Peterborough. Species selected for this study were pedunculate oak (Quercus robur L.), sycamore (Acer pseudoplatanus L.), silver birch (Betula pendula Roth.) and Norway maple (Acer platanoides L.). The mean relationship between DBH and crown diameter exhibited a restricted range (a ratio of 24 to 27) in this large sample. The results indicated that the factor of species did not have a strong impact on the allometric relationship in the case of the four species measured. It is therefore possible to produce good predictions of crown size by combining data from all the species used in this survey. A key finding of this study is that previous tree pruning and external site factors, such as hard surfacing over the rooting area and soil type, had no significant influence on the relationship between DBH and crown diameter.