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Diversity of expertise at an individual level can increase intelligence at a collective level-a type of swarm intelligence (SI) popularly known as the 'wisdom of the crowd'. However, this requires independent estimates (rare in the real world owing to the availability of public information) and contradicts people's bias for copying successful individuals. To explain these inconsistencies, 429 people took part in a 'guess the number of sweets' exercise. Guesses made with no public information were diverse, resulting in highly accurate SI. Individuals with access to the previous guess, mean guess or a randomly chosen guess, tended to over-estimate the number of sweets and this undermined SI. However, when people were provided with the current best guess, this prevented very large (inaccurate) guesses, resulting in convergence of guesses towards the true value and accurate SI across a range of group sizes. Thus, contrary to previous work, we show that social influence need not undermine SI, especially where individual decisions are made sequentially and then aggregated. Furthermore, we offer an explanation for why people have a bias to recruit and follow experts in team settings: copying successful individuals can enable accuracy at both the individual and group level, even at small group sizes.

intact fresh cadaver forelimbs, 3) ROM of skeletal forelimbs including ligaments, but without muscles and 4) ROM based on joint surfaces of the forelimb bones. A literature study provided information for level 1. A cadaver study was performed by tracking bone-pins with reflective marker triads using a 6 camera system (Vicon) to calculate 3-D ROM for levels 2 and 3. Surface scans of the bones, made with a laser surface scanner (Faro), together with Software for Interactive Musculoskeletal Modelling gave the insight necessary for level 4. The ROM was determined for flexion-extension, abduction-adduction and internal-external-rotation. The ROM values were compared between levels as well as between individual joints using ANOVA. Results: The largest variation in the reported values of the joint ROM of moving horses was observed in the fetlock. The ROM comparison between the levels showed that the ligamentous constraints resulted in the largest decreasing effect on the ROM per joint. The ROM and its increase varied between the individual levels and joints. Conclusion: The present study provided information about the ROM constraints which will be used in combination with additional extant and extinct data in our future research concerning the locomotor performances of the four monodactyl lineages. Ethical animal research: The horses were euthanatised for reasons unrelated to this study. Horse owners were aware that post-mortem examination was performed and tissues retained for research. Reasons for performing study: Horse riding in the modern race style is a complex task with the jockey mechanically isolating themselves from the movements of the horse for energetic benefit [1]. The optimum style is not clear so training is complex. Horse simulators are used in jockey training but it is not known if they accurately recreate the horse motion for optimum jockey training or motion simulation. Objectives: To quantify kinematic differences in jockey-mount interaction between racehorse and simulator riding. Study design: Prospective, cohort study. Methods: Inertial measurement units (MTw, Xsens) were attached to the sacrum of the horse/simulator, mid-thigh and tibia, sternum and pelvis of six jockeys. Both stirrups were instrumented for force measurement. Data were collected during gallop on a synthetic track and while riding a racehorse simulator (Racewood). Results: Real horse kinematics were more variable compared to the simulator, and exhibited greater vertical (47%) and medio-lateral (259%) amplitudes and smaller cranio-caudal (83%) displacement amplitude, defined using a linear mixed model (SPSS). Movement of the real horse is clockwise when viewed from the left side while the simulator trajectory is anticlockwise. Jockey pelvis displacement was 180 degrees out of phase with the horse or simulator. Peak stirrup forces during real gallop were more asymmetric and over double those recorded on the simulator. Conclusions: Racehorse simulators enable physical manipulation of jockeys into optimal positions. Their movement is...

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Visual equine lameness assessment is often unreliable, yet the full understanding of this issue is missing. Here, we investigate visual lameness assessment using near-realistic, three-dimensional horse animations presenting with 0–60 per cent movement asymmetry. Animations were scored at an equine veterinary seminar by attendees with various expertise levels. Results showed that years of experience and exposure to a low, medium or high case load had no significant effect on correct assessment of lame (P>0.149) or sound horses (P≥0.412), with the exception of a significant effect of case load exposure on forelimb lameness assessment at 60 per cent asymmetry (P=0.014). The correct classification of sound horses as sound was significantly (P<0.001) higher for forelimb (average 72 per cent correct) than for hindlimb lameness assessment (average 28 per cent correct): participants often saw hindlimb lameness where there was none. For subtle lameness, errors often resulted from not noticing forelimb lameness and from classifying the incorrect limb as lame for hindlimb lameness. Diagnostic accuracy was at or below chance level for some metrics. Rater confidence was not associated with performance. Visual gait assessment may overall be unlikely to reliably differentiate between sound and mildly lame horses irrespective of an assessor’s background.

Proximal hindlimb flexion may elevate the asymmetry of a slightly lame limb above the threshold for visibility, thus assisting in the clinical gait examination. Further work is needed to examine the causes for a positive response to flexion and possible differences between sound and lame horses as well as horses of different athletic disciplines.