Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item Relationship between experience and head kinematics in race riding jockeys(Springer Nature Limited, London, 2025-04-26) Legg KA; Cochrane DJ; Gee EK; Chin Y-Y; Rogers CWThoroughbred race-riding requires jockeys to attenuate horse movement and maintain postural stability whilst galloping at high speeds. This study aimed to investigate the head movement of jockeys in relation to race-riding experience. Accelerometer and heart rate data were collected from twelve apprentice and two senior jockeys during 85 exercise rides and 82 trial rides. Mean head displacements were determined for each jockey by double integrating the filtered acceleration data. A mixed effect multivariable linear regression model was used to investigate the relationship between jockey experience, physiological variables and head kinematics. The median (IQR) head displacement was higher for exercise riding (0.12 m, 0.09–0.14 m) than trial riding (0.06 m, 0.05–0.09 m). Jockey head displacement decreased with increasing speed of the horse (p < 0.001) and greater jockey experience (p = 0.007). Higher exercise load had a greater effect on head displacement with less experienced jockey’s (p = 0.02). The effect of speed was lower for trial riding than exercise riding (p < 0.001). More experienced jockeys had a greater ability to attenuate horse oscillation than inexperienced jockeys. This ability became more pronounced at higher exercise loads, reflecting a higher level of physical fitness and riding skill level. Measurement of jockey head displacement may provide a simple measure of assessing jockey race-riding ability or fitness.Item A threshold model to determine the association between race rides and fall risk for early career (apprentice) jockeys.(Elsevier B.V., 2024-10-31) Legg KA; Cochrane DJ; Gee EK; Rogers CWObjectives To identify descriptors associated with success in apprentice jockeys and to determine optimum numbers of jockeys for safer race riding. Design Retrospective cohort study. Methods Incidence-rates for jockey falls and success (wins per 1,000 race-starts), time and number of races spent at different apprentice levels were calculated for 807 apprentice and professional jockeys over 19 years of Thoroughbred flat racing in New Zealand (n = 524,551 race-starts). Survival analysis was used to compare career progression for jockeys that fell and those that did not, and individual seasonal fall incidence-rates were modelled. Results Apprentices had the highest fall incidence-rate in their first year of race riding (2.4, interquartile range 1.7–3.2 vs 1.1, interquartile range 1.0–1.2, p < 0.05) and a lower success incidence-rate compared to non-apprentice jockeys (71, interquartile range 67–75 vs 97 interquartile range 96–98, p < 0.05). Jockeys who fell during their apprenticeship rode in more race rides to progress towards professional status than those who did not. There was an inverse power relationship between fall incidence-rate and race rides per season for jockeys, with the inflection point at 33 rides per season. Half (48 %) of the jockeys rode fewer than 33 rides per season. Conclusions There is a surplus number of jockeys, riding at high fall risk, produced than is required by the number of race riding opportunities. Greater investment into the fitness, education and selection of a smaller cohort of dedicated apprentices, may be beneficial to reduce the risk of early career fall or injury in jockeys and requires further investigation.Item Physical Fitness of Thoroughbred Horse Racing Jockeys(Springer Nature, 2023-10-30) Legg KA; Cochrane DJ; Gee EK; Chin YY; Rogers CWPurpose Thoroughbred racing jockeys compete at maximum physiological capacity in a sport with a high risk of falls and injury. A greater understanding of the physical capacities determining jockey performance may lead to minimum physical performance parameters and corrective interventions to improve jockey fitness and performance and reduce jockey and horse injury. The aim of this study was to develop appropriate physical testing procedures for jockeys and a physical fitness profile for different licence levels. Methods Fifty-eight jockeys (n = 24 females, n = 34 males), representing all apprentice jockeys licenced in New Zealand in 2021 (100%, n = 8 probationers and n = 39 apprentices) and eleven professional jockeys (14%) were assessed to determine baseline physiological and fitness data. Descriptive statistics and boxplots were used to compare aerobic fitness, abdominal (core), upper and lower body strength, muscular power, reaction time, flexibility and a novel ‘saddle’ test targeting lower body strength, balance, and endurance between licencing levels. Effect Size (ES) was used to determine magnitude of differences between groups. Results More experienced jockeys had greater relative lower body strength (ES = 0.2–0.7) and better balance (ES = 0.5–0.9) compared to the less experienced groups. Jockeys who were in the top 20 of the premiership table (jockey rankings) had faster reaction times (ES = 0.7) and greater core extensor strength (ES = 0.7) than other cohorts. Most tests showed little differentiation between jockey licence levels, however the ‘saddle test’ showed greater variability in the less experienced race riders. This test may be an effective measure of jockey baseline performance. Conclusions These data could be used to inform minimum jockey licencing requirements and future physical fitness training programmes to increase jockey physiological fitness, thereby minimising risk of falls or injury due to physiological deficits and performance.Item Effect of Resonant Frequency Vibration on Delayed Onset Muscle Soreness and Resulting Stiffness as Measured by Shear-Wave Elastography.(MDPI (Basel, Switzerland), 2021-07-24) Jones GC; Blotter JD; Smallwood CD; Eggett DL; Cochrane DJ; Feland JB; Marino J; Scudiero OThis study utilized resonant frequency vibration to the upper body to determine changes in pain, stiffness and isometric strength of the biceps brachii after eccentric damage. Thirty-one participants without recent resistance training were randomized into three groups: a Control (C) group and two eccentric exercise groups (No vibration (NV) and Vibration (V)). After muscle damage, participants in the V group received upper body vibration (UBV) therapy for 5 min on days 1-4. All participants completed a visual analog scale (VAS), maximum voluntary isometric contraction (MVIC), and shear wave elastography (SWE) of the bicep at baseline (pre-exercise), 24 h, 48 h, and 1-week post exercise. There was a significant difference between V and NV at 24 h for VAS (p = 0.0051), at 24 h and 1-week for MVIC (p = 0.0017 and p = 0.0016, respectively). There was a significant decrease in SWE for the V group from 24-48 h (p = 0.0003), while there was no significant change in the NV group (p = 0.9341). The use of UBV resonant vibration decreased MVIC decrement and reduced VAS pain ratings at 24 h post eccentric damage. SWE was strongly negatively correlated with MVIC and may function as a predictor of intrinsic muscle state in the time course of recovery of the biceps brachii.Item Strength and Strength-Related Anthropometric Parameters of the International Level Canoe Slalom Male Paddlers(Sociedad Chilena de Anatomía, 2022-06-06) Busta J; Coufalová K; Cochrane DJThe aim of the study was to determine the differences in hand-grip strength and strength-related anthropometric parameters between the highest-performance international paddlers (HILP) and other international paddlers (ILP) in canoe slalom. In male competitors (n=48; 23 canoeists and 25 kayakers) who took part in the 2018 European championship event in canoe slalom in Prague, Czech Republic representing 15 European countries were measured hand-grip strength and strength-related anthropometric parameters two days prior the event. Differences between the group of HILP (medallists from Olympic Games, world championship and European championship in the previous three years and European championship finalists at the same time) and ILP were found. HILP have significantly higher forearm, arm and chest girths than ILP. Moderate or high practical differences and margin statistic differences were found also for hand-grip strength, body weight, body mass index and age. The consistently high-performing paddlers are heavier, have more muscular upper body and are stronger than the other group, while keeping their lower body lean. Therefore, regular upper-body strength training to all canoe slalom paddlers is important but caution is required because body weight over 80 kg may be a limiting factor. El objetivo del estudio fue determinar las diferencias en la fuerza de prensión manual y los parámetros antropométricos relacionados con la fuerza entre los remeros internacionales de alto rendimiento (RIAR) y otros remeros internacionales de canotaje en slalom. En hombres competidores (n=48; 23 piragüistas y 25 kayakistas) que participaron en el campeonato europeo de slalom en canoa de 2018, en Praga, República Checa, que representa a 15 países europeos, se midió la fuerza de agarre manual y los parámetros antropométricos relacionados con la fuerza dos días antes del evento. Se encontraron diferencias entre el grupo de RIAR (medallistas de Juegos Olímpicos, campeonatos del mundo y campeonatos de Europa en los tres años anteriores y finalistas del campeonato de Europa al mismo tiempo) y remeros internacionales. Los RIAR presentaban circunferencias de antebrazo, brazo y pecho significativamente más altas que los remeros internacionales. Además, se encontraron diferencias prácticas moderadas o altas y diferencias estadísticas en el límite para la fuerza de prensión manual, el peso corporal, el índice de masa corporal y la edad. Los remeros de alto rendimiento son más pesados, tienen la parte superior del cuerpo más musculosa y son más fuertes que el otro grupo, mientras mantienen la parte inferior del cuerpo esbelta. Por lo tanto, es importante el entrenamiento regular de fuerza de la parte superior del cuerpo para todos los remeros de piragüismo, sin embargo se requiere precaución debido a que el peso corporal superior a 80 kg puede ser un factor limitante.Item Preliminary Examination of the Biological and Industry Constraints on the Structure and Pattern of Thoroughbred Racing in New Zealand over Thirteen Seasons: 2005/06-2017/18(MDPI (Basel, Switzerland), 2021-10) Legg KA; Gee EK; Cochrane DJ; Rogers CW; Peterson MThis study aimed to examine thirteen seasons of flat racing starts (n = 388,964) in the context of an ecological system and identify metrics that describe the inherent characteristics and constraints of the New Zealand Thoroughbred racing industry. During the thirteen years examined, there was a 2-3% per year reduction in the number of races, starts and number of horses. There was a significant shift in the racing population with a greater number of fillies (aged 2-4 years) having a race start, and subsequent longer racing careers due to the inclusion of one more racing preparation post 2008 (p < 0.05). Additionally, there was an increasingly ageing population of racehorses. These changes resulted in more race starts in a career, but possibly because of biological constraints, there was no change in the number of race starts per season, starts per preparation, or days spelling between preparations (p < 0.05). There was no change in the proportion of horses having just one race start (14% of new entrants), indicating that the screening for suitability for a racing career remained consistent. These data identify key industry parameters which provide a basis for future modelling of intervention strategies to improve economic performance and reduce horse injury. Consideration of the racing industry as a bio-economic or ecological model provides framework to test how the industry may respond to intervention strategies and signal where changes in system dynamics may alter existing risk factors for injury.Item The effect of repetitive rugby scrummaging on force output and muscle activity(Georg Thieme, 1/06/2017) Cochrane DJ; Harnett K; Lopez-Villalobos N; Hapeta JWDuring rugby scrummaging, front row forwards encounter high levels of force that has been suggested to cause transient fatigue and is likely to reduce subsequent performance. However, little is known about the effect of repetitive scrummaging on force output and onset of fatigue. Twelve male front row forwards (21.5 ± 2.3 yr; height 185.7 ± 4.4 cm; body mass 108.5 ± 7.1 kg) each performed three sets of five maximaleffort isometric scrums for 10 s, with 40 s rest separating each repetition; 2 min recovery was provided between each set. Force output and electromyography (EMG) of the right medial gastrocnemius (MG), biceps femoris (BF), gluteus maximus (GM), erector spinae (ES), rectus abdominis (RA), external oblique (EO), internal oblique (IO), and rectus femoris (RF) were assessed. There was no significant force decrement from performing 15 scrums and no fatigue was detected from EMG median frequency and mean amplitude. For training and practice purposes, coaches and trainers can be confident that 15 individual repetitive static scrums against a machine are unlikely to cause a reduction in force production and promote fatigue. However, the effect of rugbyrelated activities in conjunction with scrummaging requires further research to determine if transient fatigue is causal to scrummaging for subsequent performance