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1.
J Sports Sci ; 38(6): 676-681, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32028853

RESUMEN

The aim of this study was to assess if tactical and technical performance indicators (PIs) could be used in combination to model match outcomes in Australian Football (AF). A database of 101 technical PIs and 14 tactical PIs from every match in the 2009-2016 Australian Football League (AFL) seasons was merged. Two outcome measures Win-loss and Score margin were used as dependent variables. The top 45 ranked technical and tactical PIs from a feature selection process were used to model match outcome using decision tree and Generalised Linear Models (GLMs). Of the top 45 selected features, this included seven tactical PIs. The Win-loss-based Decision tree model achieved a classification accuracy of 89.0% and GLM 93.2%. A Score margin-based GLM achieved a root mean squared error (RMSE) of 6.9 points. A combined approach to the classification of match outcomes provided no improvement in model accuracy compared with previous literature. However, this study has established the relative importance of technical and tactical measures of performance in relation to successful team performance in AF.


Asunto(s)
Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Árboles de Decisión , Modelos Lineales , Fútbol/fisiología , Australia , Humanos , Análisis y Desempeño de Tareas
2.
J Sports Sci ; 38(6): 703-709, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32050847

RESUMEN

Recently, there has been much controversy over the International Association of Athletics Federation (IAAF) regulations regarding eligibility to compete and natural testosterone levels in female athletes. Much interest lies in the analysis of Caster Semenya's extraordinary performance. The objective of this work were, a) Complete an analysis of Caster Semenya's results during the 800m finals and b) search for existing similar performances by other female athletes. We analysed the results of the finals of all IAAF World Championships and Olympic Games from 1984-2016, including the 800m results of the Diamond Leagues 2016-2018. Exponential curves were fit to the data to characterise and predict performance for each event. Caster Semenya's finishing times before her ineligibility to compete and after the suspension of the IAAF hyperandrogenism regulation were found to be 1.24% and 1.49%, respectively, faster than the characteristic performance of the elite-standard in the women's 800m final. Other female athletes, with finishing times faster than the ones predicted by the characteristic curves were also discovered. The percentage difference in performance between Caster Semenya and the other participants did not reach 3% in the 800m event. No conclusions can be drawn regarding extraordinary results ever performed during the 100m, 200m or 400m finals.


Asunto(s)
Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Hiperandrogenismo , Deportes/legislación & jurisprudencia , Atletismo/fisiología , Femenino , Humanos , Masculino , Caracteres Sexuales
3.
J Sports Sci ; 38(5): 568-575, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32019482

RESUMEN

This study aimed to assess the effect of playing surface (Natural [NT] and Artificial [AT] Turf) on the fatigue response to a soccer-specific exercise protocol (SSEP). Eighteen male soccer players completed the SSEP on NT and AT with pre-, post-, and 48 h post-assessments of eccentric knee flexor (eccKF) and concentric knee extensor peak torque (PT), peak countermovement (CMJ) and squat jump (SJ) height, and Nordic hamstring break angle. No significant main effects for surface or any surface and time interactions were observed for any of the outcome measures, except for eccKF PT recorded at 3.14 rad·s-1, which was significantly lower 48 h post-trial in the AT condition (AT = 146.3 ± 20.4 Nm; NT = 158.8 ± 24.7 Nm). Main effects for time were observed between pre- and post-trial measures for eccKF PT at all angular velocities, Nordic break angle, CMJ and SJ height. Nordic break angle, and both CMJ and SJ height were significantly impaired 48 h post-trial when compared to pre-trial. The findings of the current study suggest surface dependent changes in eccKF PT which may have implications for recovery and subsequent performance after competition on AT.


Asunto(s)
Planificación Ambiental , Ejercicio/fisiología , Articulación de la Rodilla/fisiología , Fatiga Muscular/fisiología , Músculo Esquelético/fisiología , Fútbol/fisiología , Adulto , Rendimiento Atlético/fisiología , Estudios Cruzados , Músculos Isquiotibiales/fisiología , Humanos , Masculino , Fenómenos Fisiológicos Musculoesqueléticos , Rendimiento Físico Funcional , Rango del Movimiento Articular , Fútbol/lesiones , Torque , Adulto Joven
4.
J Sports Sci ; 38(6): 710-716, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32079484

RESUMEN

The purpose of this study was to investigate the validity of a smartphone app to measure biomechanical barbell parameters during the snatch. Ten collegiate NCAA division I athletes performed two repetitions each at 40, 50, 60, 70, and 80% of their 1-repetition maximum snatch. Barbell motions were simultaneously recorded with a motion capture system and the smartphone app. The motion capture system recorded the 3-D position of a reflective marker attached to the end of the barbell while the smartphone app was used to record sagittal plane video and track the shape of the weight plate from which the barbell center was derived. Peak forward (PFD) and backward (PBD) displacements and peak vertical displacement (PVD) and velocity (PVV) were calculated from both sets of data. Significant, strong to very strong Pearson's product-moment correlation coefficients between both systems were noted for all parameters (r = 0.729-0.902, all p < 0.001). Small significant biases between systems were observed for PVD (ES = 0.284, p < 0.001) and PFD (ES=0.340, p < 0.01), while trivial to small, non-significant biases were observed for PBD (ES = 0.143) and PVV (ES = -0.100). Collectively, the results suggest that the app can provide biomechanical data of barbell motions similar to a 3-D motion capture system.


Asunto(s)
Rendimiento Atlético/fisiología , Teléfono Inteligente , Validación de Programas de Computación , Levantamiento de Peso/fisiología , Fenómenos Biomecánicos , Humanos , Reproducibilidad de los Resultados , Estudios de Tiempo y Movimiento , Adulto Joven
5.
Sports Health ; 12(2): 189-199, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32023171

RESUMEN

CONTEXT: Cannabis use has increased, in large part due to decriminalization. Despite this increase in usage, it remains unclear what proportion of athletes use cannabis and what effect it has on athletic performance and recovery. OBJECTIVE: To systematically review cannabis use among athletes, including epidemiology, effect on performance and recovery, and regulations for use in sport. DATA SOURCES: PubMed, MEDLINE, and EMBASE databases were queried from database inception through November 15, 2018. A hand search of policies, official documents, and media reports was performed for relevant information. STUDY SELECTION: All studies related to cannabis use in athletes, including impact on athletic performance or recovery, were included. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Demographic and descriptive data of included studies relating to epidemiology of cannabis use in athletes were extracted and presented in weighted means or percentages where applicable. RESULTS: Overall, 37 studies were included, of which the majority were cross-sectional studies of elite and university athletes. Among 11 studies reporting use among athletes (n = 46,202), approximately 23.4% of respondents reported using cannabis in the past 12 months. Two studies found a negative impact on performance, while another 2 studies found no impact. There was no literature on the influence of cannabis on athletic recovery. Across athletic organizations and leagues, there is considerable variability in acceptable thresholds for urine tetrahydrocannabinol levels (>15 to 150 ng/mL) and penalties for athletes found to be above these accepted thresholds. CONCLUSION: Overall, these results suggest that approximately 1 in 4 athletes report using cannabis within the past year. Based on the available evidence, cannabis does not appear to positively affect performance, but the literature surrounding this is generally poor. Given the variability in regulation across different sport types and competition levels, as well as the growing number of states legalizing recreational cannabis use, there is a need to improve our understanding of the effects of cannabis use on the athlete and perhaps adopt a clearer and overarching policy for the use of cannabis by athletes in all sports and at all levels.


Asunto(s)
Abuso de Marihuana/epidemiología , Fumar Marihuana/epidemiología , Deportes/estadística & datos numéricos , Rendimiento Atlético/fisiología , Dronabinol/orina , Humanos , Política Organizacional , Deportes/legislación & jurisprudencia , Detección de Abuso de Sustancias
7.
Mol Genet Genomics ; 295(2): 515-523, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31897802

RESUMEN

Adaptation to exercise training is a complex trait that may be influenced by genetic variants. We identified 36 single nucleotide polymorphisms (SNPs) that had been previously associated with endurance or strength performance, exercise-related phenotypes or exercise intolerant disorders. A MassARRAY multiplex genotyping assay was designed to identify associations with these SNPs against collected endurance fitness phenotype parameters obtained from two exercise cohorts (Gene SMART study; n = 58 and Hawaiian Ironman Triathlon 2008; n = 115). These parameters included peak power output (PP), a time trial (TT), lactate threshold (LT), maximal oxygen uptake (VO2 max) in recreationally active individuals and a triathlon time-to-completion (Hawaiian Ironman Triathlon cohort only). A nominal significance threshold of α < 0.05 was used to identify 17 variants (11 in the Gene SMART population and six in the Hawaiian Ironman Triathlon cohort) which were significantly associated with performance gains in highly trained individuals. The variant rs1474347 located in Interleukin 6 (IL6) was the only variant with a false discovery rate < 0.05 and was found to be associated with gains in VO2 max (additional 4.016 mL/(kg min) for each G allele inherited) after training in the Gene SMART cohort. In summary, this study found further evidence to suggest that genetic variance can influence training response in a moderately trained cohort and provides an example of the potential application of genomic research in the assessment of exercise trait response.


Asunto(s)
Adaptación Fisiológica/genética , Rendimiento Atlético/fisiología , Ejercicio/fisiología , Resistencia Física/genética , Adulto , Genoma Humano/genética , Genotipo , Humanos , Ácido Láctico/metabolismo , Masculino , Polimorfismo de Nucleótido Simple/genética
8.
J Sports Sci ; 38(5): 528-533, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31918624

RESUMEN

Although breast pain is problematic for many active women, no published research has investigated breast pain experienced by elite female athletes. This study aimed to examine the extent that mastalgia and exercise-induced breast pain affected the sporting performance of elite female athletes during training and competition. A custom-designed online survey with questions related to sport participation, as well as the frequency, severity and perceived performance effects of mastalgia and exercise-induced breast pain, was distributed to sporting organisations, coaches, medical staff and teams/clubs throughout Australia. Five hundred and forty female athletes competing nationally or internationally across 49 different sports participated in the survey. Sixty-three percent of respondents reported experiencing breast pain associated with their menstrual cycle and 33% reported that this pain worsened during activity. Forty-four percent of athletes reported experiencing exercise-induced breast pain during training or competition. Both types of breast pain were also reported to negatively affect sporting performance (20% and 32%, respectively). Mastalgia associated with the menstrual cycle and exercise-induced breast pain should be acknowledged as potential problems affecting the sporting performance of elite female athletes. Awareness around the impact of breast pain and the development and implementation of breast pain management strategies are essential for this population.


Asunto(s)
Atletas , Rendimiento Atlético/fisiología , Dismenorrea/fisiopatología , Mastodinia/fisiopatología , Adolescente , Adulto , Anciano , Australia , Dismenorrea/epidemiología , Femenino , Encuestas Epidemiológicas , Humanos , Mastodinia/epidemiología , Mastodinia/etiología , Ciclo Menstrual/fisiología , Persona de Mediana Edad , Dimensión del Dolor , Índice de Severidad de la Enfermedad , Adulto Joven
9.
Int J Sports Med ; 41(3): 161-167, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31902130

RESUMEN

Aerobic performance is negatively impacted by tropical climate due to impairment of thermoregulatory mechanisms. We tested the hypothesis that a torso application of a 4% menthol solution would have the same effect on a best performance 10-km run as an external use of cold water. Thirteen trained male athletes completed four outdoor 10-km runs (T=29.0±1.3°C, relative humidity 59.0±13.6%) wearing a tee-shirt soaked every 2-km either in a cold (~6°C) or warm/ambient (~28°C) solution, consisting in water or in a 4% menthol solution, (CTL, MENT-Amb, CLD and MENT-CLD). Run performances were improved from 4.8 to 6.1% in CLD (51.4±5.5 min), MENT-Amb (52.2±5.9 min) and MENT-CLD (51.4±5.1 min) conditions (vs. CTL, 55.4±8.4 min, P<0.05), without differences between these three conditions, whereas heart rate (177±13bpm), body temperature (38.7±0.6°C) and drink ingestion (356±170 g) were not modified. Thermal sensation after running was lower in MENT-CLD (vs. CTL, P<0.01) and thermal acceptability was higher in CLD and MENT-Amb (vs. CTL, P<0.05), but thermal comfort, feeling scale and rate of perceived exertion remained unchanged. The use of menthol on skin enhances aerobic performance in a tropical climate, and no differences in performance were observed between menthol and traditional percooling strategies. However, combining both menthol and traditional percooling brought no further improvements.


Asunto(s)
Rendimiento Atlético/fisiología , Regulación de la Temperatura Corporal/efectos de los fármacos , Humedad , Mentol/administración & dosificación , Carrera/fisiología , Clima Tropical , Administración Cutánea , Adulto , Ingestión de Líquidos , Marcha/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Pérdida de Peso/fisiología , Adulto Joven
10.
J Sports Sci ; 38(5): 511-517, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31902294

RESUMEN

This study investigated the effects of a 4-week training with hand paddles (HPD) on front-crawl swimming performance (SP), clean swimming speed (SPEED), stroke rate (SR), stroke length (SL) and tethered force (TF). Twenty swimmers (10 men and 10 women) were paired according to performance and gender, and were randomly assigned to control (CON, 22.4 ± 2.3 years) or HPD (21.8 ± 1.9 years) groups. During 4 weeks both groups performed the same training, except for a sprint training set (3 times/week, 10 × 10 strokes all-out, 1-min rest) completed with (HPD = 320 cm2) and without (CON) paddles. Afterwards, both groups performed the same training over a 2-week taper period. SP, SPEED, SR, SL and TF were assessed before (PRE) and after the 4-week period (POST), after the first (T1) and second taper weeks (T2). Swimmers rated their perceived exertion for the sprint training set (RPETS) and the training session for determining internal training load (ITL). SP, SPEED, SR, SL and TF did not change from PRE to POST, T1 and T2. ITL and RPETS were not different between groups. Training 4 weeks with HPD does not affect swimming performance, so the use of HPD remains unsupported in such period.


Asunto(s)
Rendimiento Atlético/fisiología , Equipo Deportivo , Natación/fisiología , Femenino , Mano , Humanos , Masculino , Factores de Tiempo , Adulto Joven
11.
J Sports Sci ; 38(2): 140-149, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31680636

RESUMEN

The aim of this study was to assess the influence of a half-time (HT) re-warm up (RWU) strategy on measures of performance and the physical and perceptual response to soccer-specific activity. Ten male soccer players completed a control (CON) and RWU trial, in which participants completed 60 min (4 x 15-min periods with a 15-min HT interspersing the third and fourth periods) of a soccer-specific exercise protocol. The CON trial comprised a passive 15-min HT, whilst the RWU trial comprised a passive 12-min period, followed by a 3-min RWU. The RWU elicited an improvement in 20 m sprint times (d= 0.6; CON: 3.42 ± 0.20 s; RWU: 3.32 ± 0.12 s), and both squat (d= 0.6; CON: 26.96 ± 5.00 cm; RWU: 30.17 ± 5.13 cm) and countermovement jump height (d= 0.7; CON: 28.15 ± 4.72 cm; RWU: 31.53 ± 5.43 cm) following the RWU and during the initial stages of the second half. No significant changes were identified for 5 m or 10 m sprint performance, perceived muscle soreness, or PlayerLoadTM. Ratings of perceived exertion were however higher (~2 a.u) following the RWU. These data support the use of a HT RWU intervention to elicit acute changes in performance.


Asunto(s)
Rendimiento Atlético/fisiología , Rendimiento Atlético/psicología , Fútbol/fisiología , Ejercicio de Calentamiento/fisiología , Adulto , Estudios Cruzados , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Mialgia/psicología , Percepción/fisiología , Esfuerzo Físico/fisiología , Proyectos Piloto , Ejercicio Pliométrico/psicología , Adulto Joven
12.
J Sports Sci ; 38(2): 206-213, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31722621

RESUMEN

A novel 3D motion capture analysis assessed the efficacy of insoles in maintaining the foot position on the midsole platform inside the shoe during rapid change of direction manoeuvres used in team sports. An insole (TI) with increased static (35%) and dynamic (49%) coefficient of friction compared to a regular insole (SI) was tested. Change of direction performance was faster (p < .001) and perceived to be faster (p < .001) in TI compared to SI. Participants utilised greater coefficient of friction in TI compared to SI during a complete turn, but not during a 20 degree side-cut. In-shoe foot sliding reduced across the forefoot and midfoot during the braking phase of the turn and in the rearfoot during the side-cut in TI. Greater in-shoe foot sliding occurred in the turn than the side-cut across all foot regions. Results provide guidance for athletic footwear design to help limit in-shoe foot sliding and improve change of direction performance.


Asunto(s)
Rendimiento Atlético/fisiología , Diseño de Equipo , Destreza Motora/fisiología , Zapatos , Adulto , Rendimiento Atlético/psicología , Fenómenos Biomecánicos , Femenino , Fricción , Humanos , Masculino , Percepción , Estudios de Tiempo y Movimiento , Adulto Joven
13.
J Sports Sci ; 38(2): 214-230, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31795815

RESUMEN

Injuries and lack of motivation are common reasons for discontinuation of running. Real-time feedback from wearables can reduce discontinuation by reducing injury risk and improving performance and motivation. There are however several limitations and challenges with current real-time feedback approaches. We discuss these limitations and challenges and provide a framework to optimise real-time feedback for reducing injury risk and improving performance and motivation. We first discuss the reasons why individuals run and propose that feedback targeted to these reasons can improve motivation and compliance. Secondly, we review the association of running technique and running workload with injuries and performance and we elaborate how real-time feedback on running technique and workload can be applied to reduce injury risk and improve performance and motivation. We also review different feedback modalities and motor learning feedback strategies and their application to real-time feedback. Briefly, the most effective feedback modality and frequency differ between variables and individuals, but a combination of modalities and mixture of real-time and delayed feedback is most effective. Moreover, feedback promoting perceived competence, autonomy and an external focus can improve motivation, learning and performance. Although the focus is on wearables, the challenges and practical applications are also relevant for laboratory-based gait retraining.


Asunto(s)
Rendimiento Atlético/fisiología , Rendimiento Atlético/psicología , Retroalimentación , Monitores de Ejercicio , Motivación , Carrera/fisiología , Carrera/psicología , Traumatismos en Atletas/prevención & control , Fenómenos Biomecánicos , Marcha/fisiología , Humanos , Percepción , Carrera/lesiones
14.
J Sports Sci ; 38(1): 1-5, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31575324

RESUMEN

Previous research has shown enhanced performance and altered pacing behaviour in the presence of a virtual opponent during middle-distance cycling time trials with a duration of 2 min and longer. The purpose of this study was to determine whether these effects are also present in cycling time trials of shorter duration. Twelve physically active men completed three 1-km time trials. After a familiarisation trial (FAM), participants performed two experimental conditions: one without opponent (NO) and one with a virtual opponent (OP). Repeated-measures ANOVAs were used to assess differences in pacing and performance using power output and duration (p<0.05). No differences in mean finishing times (FAM: 91.5 ± 7.7 s; NO: 91.6 ± 6.4 s; OP: 90.9 ± 4.9 s; p=0.907) or power output (FAM: 382 ± 111 W; NO: 363 ± 80 W; OP: 367 ± 67; p=0.564) were found between experimental conditions. Furthermore, no differences in pacing profiles between experimental conditions were found (p=0.199). Similarly, rate of perceived exertion did not differ between experimental conditions at any moment (p=0.831). In conclusion, unlike events of a more prolonged duration (>2 min), the presence of an opponent did not affect participants' pacing behaviour in short duration 1-km time trials.


Asunto(s)
Rendimiento Atlético/fisiología , Ciclismo/fisiología , Conducta Competitiva/fisiología , Adulto , Rendimiento Atlético/psicología , Ciclismo/psicología , Toma de Decisiones , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Factores de Tiempo , Adulto Joven
15.
J Sports Sci ; 38(1): 29-37, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31631783

RESUMEN

This study investigated the role of reactive and eccentric strength in stiffness regulation during maximum velocity sprinting (Vmax) in team sport athletes compared with highly trained sprinters. Thirteen team sport athletes and eleven highly trained sprinters were recruited. Vmax was measured using radar, and stiffness regulation was inferred from modelled vertical and leg spring stiffness. Reactive strength (RSI) was determined from a 0.50 m drop jump, and an eccentric back squat was used to assess maximum isoinertial eccentric force. Trained sprinters attained a higher Vmax than team sport athletes, partly due to a briefer contact time and higher vertical stiffness. Trained sprinters exhibited a moderately higher RSI via the attainment of a briefer and more forceful ground contact phase, while RSI also demonstrated large to very large associations with vertical stiffness and Vmax, respectively. Isoinertial eccentric force was largely correlated with Vmax, but only moderately correlated with vertical stiffness. Reactive and eccentric strength contribute to the ability to regulate leg spring stiffness at Vmax, and subsequently, the attainment of faster sprinting speeds in highly trained sprinters versus team sport athletes. However, stiffness regulation appears to be a task-specific neuromuscular skill, reinforcing the importance of specificity in the development of sprint performance.


Asunto(s)
Rendimiento Atlético/fisiología , Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Acondicionamiento Físico Humano , Carrera/fisiología , Aceleración , Adulto , Fenómenos Biomecánicos , Estudios Transversales , Femenino , Humanos , Masculino , Adulto Joven
16.
J Sports Sci ; 38(1): 53-61, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31623521

RESUMEN

This study aimed 1) to examine the validity of inertial measurement unit (IMU)-based hip flexion strength test, and 2) to investigate the hip flexion strength test as an indicator of sprint performance. Eight males performed five repeated hip flexion-extension, while leg motion was recorded using an IMU and a motion capture system (Mocap). As the second experiment, 24 male athletes performed the IMU-based hip flexion strength test and sprinted 50 m, during which step-to-step ground reaction force (GRF) was recorded. The strength test variables were calculated using IMU and Mocap data including angular impulse, mean moment, and positive and negative work and power. Using GRF data, step-to-step spatiotemporal variables were obtained. The results showed high intra-class correlation coefficient and correlation coefficient (both >0.909) between IMU and Mocap for angular impulse, mean moment, positive work and power. The hip flexion mean moment showed significant correlation with running speed from the 5th-8th step section onwards. The angular impulse, mean moment, positive work and power are recommended to be used for the IMU-based hip flexion strength test variables in terms of accuracy and validity. Moreover, the proposed IMU-based hip flexion strength test can be an indicator for better sprinting performance.


Asunto(s)
Rendimiento Atlético/fisiología , Prueba de Esfuerzo/métodos , Cadera/fisiología , Fuerza Muscular/fisiología , Carrera/fisiología , Aceleración , Adulto , Fenómenos Biomecánicos , Humanos , Masculino , Reproducibilidad de los Resultados , Estudios de Tiempo y Movimiento , Adulto Joven
17.
J Sports Sci ; 38(3): 280-287, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31766951

RESUMEN

Delivering a cricket ball with a wrist-spin (WS) bowling technique is considered one of the game's most difficult skills. Limited biomechanical information exists for WS bowlers across skill levels. The purpose of this study was to compare biomechanical, isokinetic strength and anthropometric measures between elite (12) and pathway bowlers (eight). Data were collected using a motion analysis system, dynamometer and a level-two anthropometrist. A regression analysis identified that performance was best explained by increased wrist radial deviation torque and longitudinal axis rotational moments at the shoulder and wrist. From back foot impact (BFI) to ball release (BR), elite bowlers rotated their trunks less, experienced less trunk deceleration resulting in a more front-on position and increased pelvis rotation angular velocity. They also displayed an increased shoulder internal rotation moment as the upper arm moved from external into internal rotation and was a major contributor in the subsequent differences observed in the distal segments of the bowling limb. Anthropometric differences were observed at the wrist and finger joints and may be used to form the basis for talent identification programmes. This study highlights the important contribution to bowling performance of the musculature responsible for producing long axis rotations of the bowling limb.


Asunto(s)
Antropometría , Rendimiento Atlético/fisiología , Destreza Motora/fisiología , Fuerza Muscular/fisiología , Extremidad Superior/fisiología , Adolescente , Adulto , Humanos , Masculino , Pelvis/fisiología , Rango del Movimiento Articular/fisiología , Rotación , Tórax/fisiología , Estudios de Tiempo y Movimiento , Adulto Joven
18.
J Sports Sci ; 38(3): 330-335, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31774365

RESUMEN

The aim of this novel study was to analyse key kinematic variables during the water jump clearance amongst world-class 3,000 m steeplechasers. Thirteen men and 13 women were recorded as they negotiated the last water jump in the 2017 IAAF World Championship finals. Video footage (100 Hz) was recorded using three high-definition camcorders to derive spatiotemporal data; spatial data were normalised to athletes' statures. The time to cover the distance from 4.5 m before the water jump barrier to 4.5 m after ("9 m time") was used to describe overall clearance success. Although men had longer approach and exit step lengths, there were no differences when the data were normalised; by contrast, men's landing distances were greater in both absolute and relative terms. Women's shorter landing distances meant negotiating deeper water when exiting, with those athletes with longer landing distances running faster 9 m times (r = - 0.87). Obtaining a high position on the barrier (clearance height) was correlated with longer landing distances (men: r = 0.75, women: r = 0.71) and could indicate better technique. Coaches should note that although technical proficiency in all aspects of the clearance is imperative, optimising the athlete's landing distance is paramount.


Asunto(s)
Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Deportes/fisiología , Adulto , Animales , Fenómenos Biomecánicos , Femenino , Caballos , Humanos , Masculino , Factores Sexuales , Estudios de Tiempo y Movimiento , Adulto Joven
19.
J Sports Sci ; 38(1): 46-52, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31658889

RESUMEN

The purpose of this study was to determine the influence of pelvis and torso angular jerk on a performance indicator of hitting, specifically hand velocity. Eighteen softball athletes were analysed (20.3 ± 1.6 years; 164.9 ± 24.9 cm; 74.4 ± 14.0 kg). Participants were instructed to execute 3 maximum effort swings off a stationary tee at the middle "strike-zone" location. Angular jerk data were analysed during the acceleration phase of the swing, the time between foot contact and ball contact. Quadratic regression analyses were conducted to examine the relationship of minimal pelvis angular jerk and minimal torso angular jerk to angular hand velocity at ball contact. No significant relationship was found between pelvis angular jerk and angular hand velocity at ball contact (r = 0.192, p = 0.754). The curvilinear regression model for pelvis angular jerk produced: R2 = 0.037; F (2, 17) = 0.288; p = 0.754. Lack of significant findings suggests a relationship between jerk and angular hand velocity does not exist within female softball hitting. Future research should investigate the timing of minimal jerk through the acceleration phase as a predictor of angular hand velocity, rather than the value of jerk itself.


Asunto(s)
Rendimiento Atlético/fisiología , Béisbol/fisiología , Mano/fisiología , Pelvis/fisiología , Torso/fisiología , Aceleración , Fenómenos Biomecánicos , Femenino , Humanos , Destreza Motora/fisiología , Movimiento/fisiología , Estudios de Tiempo y Movimiento , Adulto Joven
20.
J Sports Sci ; 38(3): 320-329, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31782684

RESUMEN

Elite athletes not only run faster, hit harder, and jump higher, but also see and react better. However, the specific visual-motor skills that differentiate high-achieving athletes are still not well understood. In this paper we examine 2317 athletes (1871 male) tested on the Nike SPARQ Sensory Station, a digital test battery measuring visual, perceptual and motor skills relevant for sports performance. We develop a multivariate Gaussian transformation model to robustly estimate visual-motor differences by level, gender, and sport type. Results demonstrate that visual-motor performance is superior for athletes at higher levels, with males faster at near-far eye movements and females faster at eye-hand reaction times. Interestingly, athletes who play interceptive sports such as baseball and tennis exhibit better measures of visual clarity, contrast sensitivity and simple reaction time, while athletes from strategic sports like soccer and basketball have higher measures of spatial working memory. These findings provide quantitative evidence of domain-specific visual expertise in athletes.


Asunto(s)
Rendimiento Atlético/fisiología , Rendimiento Atlético/psicología , Destreza Motora/fisiología , Percepción Visual/fisiología , Teorema de Bayes , Femenino , Humanos , Masculino , Memoria a Corto Plazo , Tiempo de Reacción , Análisis de Regresión , Factores Sexuales , Análisis y Desempeño de Tareas
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