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1.
J Sports Sci ; 41(10): 927-936, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37609886

RESUMEN

The understanding of rowing performance has been predominantly gained through quantitative sports science-based research. In combination with this objective information, coaches' experiences may provide important contextual information for how this quantitative evidence is implemented into training programmes. The aims of this study were to (1) explore coaches' perspectives of performance indicators for competitive rowing in junior rowers, and (2) identify coaches' recommendations for developing effective technique and movement competency among junior rowers who have the potential to transition to elite competition. Twenty-seven semi-structured interviews were conducted with experienced rowing coaches through purposive sampling of an accredited coaching network. Participants' coaching experience ranged from 5 to 46 (M = 22, SD = 10) years. Data were analysed using thematic analysis. Three overarching themes were identified including, (1) getting the basics right, (2) targeting types of talent, and (3) complexities of performance. Based on these findings, sequence and boat feel, supported through the movement competency provided by hip flexibility and the trunk musculature, were considered critical for executing correct technique. Developing talent and understanding successful performance are both complex concepts when considering the individual athlete. Coaches' perspectives provided insight into key components of performance to enhance our understanding of how to better develop junior rowers.


Asunto(s)
Tutoría , Deportes , Deportes Acuáticos , Humanos , Atletas , Encuestas y Cuestionarios
2.
Motor Control ; 20(4): 459-70, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26491902

RESUMEN

Entropy is an effective tool for investigation of human movement variability. However, before applying entropy, it can be beneficial to employ analyses to confirm that observed data are not solely the result of stochastic processes. This can be achieved by contrasting observed data with that produced using surrogate methods. Unlike continuous movement, no appropriate method has been applied to discrete human movement. This article proposes a novel surrogate method for discrete movement data, outlining the processes for determining its critical values. The proposed technique reliably generated surrogates for discrete joint angle time series, destroying fine-scale dynamics of the observed signal, while maintaining macro structural characteristics. Comparison of entropy estimates indicated observed signals had greater regularity than surrogates and were not only the result of stochastic but also deterministic processes. The proposed surrogate method is both a valid and reliable technique to investigate determinism in other discrete human movement time series.


Asunto(s)
Movimiento/fisiología , Dinámicas no Lineales , Adulto , Humanos , Masculino , Modelos Estadísticos , Adulto Joven
3.
J Sports Sci ; 33(3): 300-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25083744

RESUMEN

When characterising typical human movement profiles, the optimal number of trials analysed for each participant should ensure a stable mean. Sequential analysis is one method able to establish the number of trials to stability by assessing a moving point mean against a set bandwidth. As the total trial number determining this bandwidth is selected arbitrarily, the effect of applying different total trial numbers on the results of sequential analysis was investigated. Twenty participants performed 30 trials of overarm throwing, and sequential analyses were applied to three dimensional (3-D) kinematic data over 10, 20 and 30 trial numbers. We found a total of 20 to be the preferred trial number for sequential analyses. Erroneous results were produced consistently by 10 trial number groups, while moving point means were statistically unchanged after the 10th trial. Subsequently, sequential analyses were applied to 20 trials to establish trials to stability in discrete and time series elements of the 3-D kinematic data. The results suggest that a trial size between 13 and 17 provides stable means for overarm throwing kinematics.


Asunto(s)
Brazo/fisiología , Interpretación Estadística de Datos , Movimiento , Proyectos de Investigación , Adolescente , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Adulto Joven
4.
J Appl Biomech ; 26(3): 349-56, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20841627

RESUMEN

The purpose was to develop a foot image capture and measurement system with web cameras (the 3-FIS) to provide reliable and valid foot anthropometric measures with efficiency comparable to that of the conventional method of using a handheld anthropometer. Eleven foot measures were obtained from 10 subjects using both methods. Reliability of each method was determined over 3 consecutive days using the intraclass correlation coefficient and root mean square error (RMSE). Reliability was excellent for both the 3-FIS and the handheld anthropometer for the same 10 variables, and good for the fifth metatarsophalangeal joint height. The RMSE values over 3 days ranged from 0.9 to 2.2 mm for the handheld anthropometer, and from 0.8 to 3.6 mm for the 3-FIS. The RMSE values between the 3-FIS and the handheld anthropometer were between 2.3 and 7.4 mm. The 3-FIS required less time to collect and obtain the final variables than the handheld anthropometer. The 3-FIS provided accurate and reproducible results for each of the foot variables and in less time than the conventional approach of a handheld anthropometer.


Asunto(s)
Antropometría/instrumentación , Pie/anatomía & histología , Fotograbar/instrumentación , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
5.
Vaccine ; 28(38): 6265-72, 2010 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-20637774

RESUMEN

Eurasian badgers (Meles meles) are a reservoir host of Mycobacterium bovis and are implicated in the transmission of tuberculosis to cattle in Ireland and Great Britain. The development of a vaccine for use in badgers is considered a key element of any long-term sustainable campaign to eradicate the disease from livestock in both countries. The aim of this study was to investigate the protective response of badgers vaccinated orally with Bacille Calmette-Guérin (BCG) encapsulated in a lipid formulation, followed by experimental challenge with M. bovis. A group of badgers was vaccinated by inoculating the BCG-lipid mixture containing approximately 10(8)colony forming units (cfu) of BCG into the oesophagus. The control group was sham inoculated with the lipid formulation only. Thirteen weeks after vaccination all the badgers were challenged with approximately 10(4)cfu of M. bovis delivered by endobronchial inoculation. Blood samples were taken throughout the study and the cell mediated immune (CMI) responses in peripheral blood were monitored by the IFN-gamma ELISA and ELISPOT assay. At 17 weeks after infection all the badgers were examined post-mortem to assess the pathological and bacteriological responses to challenge. All badgers in both groups were found to be infected. However, a significant protective effect of BCG vaccination was measured as a decrease in the number and severity of gross lesions, lower bacterial load in the lungs, and fewer sites of infection. The analysis of immune responses showed that vaccination with BCG did not generate any detectable CMI immunological responses, however the levels of the responses increased in both groups following M. bovis infection. The results of the study showed that vaccination with oral BCG in the lipid formulation generated a protective effect in the badgers.


Asunto(s)
Vacuna BCG/administración & dosificación , Mustelidae/inmunología , Tuberculosis Bovina/prevención & control , Administración Oral , Animales , Vacuna BCG/inmunología , Bovinos , Femenino , Inmunidad Celular , Interferón gamma/inmunología , Pulmón/patología , Ganglios Linfáticos/microbiología , Masculino , Mycobacterium bovis/inmunología , Tuberculosis Bovina/inmunología
6.
J Sports Sci ; 27(1): 37-47, 2009 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-19031333

RESUMEN

In this study, video and force analysis techniques were used to distinguish between dragon boat paddlers of different ability. Six elite paddlers (three males, three females) and six sub-elite paddlers (two males, four females) were compared during high-intensity paddling (80-90 strokes.min(-1)). Video filming was conducted for two-dimensional kinematic analysis and an instrumented paddle was used to collect force data. Paddling efficiency, paddle force characteristics, and paddler kinematic variables were measured. Elite paddlers achieved higher paddling efficiency than sub-elite paddlers (elite: 76+/-4%; sub-elite: 67+/-10%; P=0.080). Elite paddlers also showed higher peak force (elite: 16.3+/-4.8 N.kg(-2/3); sub-elite: 11.4+/-2.6 N.kg(-2/3); P=0.052), average force (elite: 7.9+/-2.8 N.kg(-2/3); sub-elite: 5.5+/-1.4 N.kg(-2/3); P=0.084), and impulse (elite: 3.0+/-0.9 (N.s).kg(-2/3); sub-elite: 1.9+/-0.4 (N.s).kg(-2/3); P=0.026) than sub-elite paddlers, but these three results should be viewed with caution due to the small sample size and the unequal number of males and females in the two groups. Superior technique and greater strength enable the elite paddlers to achieve higher paddling efficiency. Paddlers use different joint movement patterns to develop propulsion, which are reflected in variations in the force-time curve.


Asunto(s)
Rendimiento Atlético , Fenómenos Biomecánicos , Metabolismo Energético , Navíos , Deportes/fisiología , Adulto , Peso Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad
7.
Tuberculosis (Edinb) ; 88(6): 601-9, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18468490

RESUMEN

Mycobacterium bovis is endemic in badger (Meles meles) populations of Ireland and the United Kingdom and infected badgers are a potential source of infection for cattle. In domestic livestock tuberculosis causes economic losses from lost production and the costs associated with eradication programmes, and in addition there is a risk of zoonotic infection. Whereas culling is currently used to control tuberculous badger populations in Ireland, vaccination, if it were available, would be preferred. A study was undertaken to examine the protective responses of badgers vaccinated either by the subcutaneous or mucosal (intranasal and conjunctival) routes with bacille Calmette-Guérin (BCG), when challenged with M. bovis by the endobronchial route. Three groups of badgers were used. The first group (n=4) was vaccinated with approximately 5 x 10(5) colony forming units (cfu) of BCG by subcutaneous injection. In the second group (n=5) badgers were vaccinated via the mucosal route by instilling 1.0 x 10(5)cfu into each conjunctival sac and spraying 1.0 x 10(5)cfu into each nostril (final vaccine dose of 4 x 10(5)cfu). The control (n=5) badgers served as a non-vaccinated group. Twelve weeks post-vaccination all badgers in the three groups were challenged with approximately 10(4)cfu of M. bovis by endobronchial inoculation. At 12 weeks post-infection all badgers were examined post-mortem to assess the pathological and bacteriological responses to challenge. Gross and histological lesions of tuberculosis were seen in all challenged badgers and M. bovis was recovered from all challenged badgers. However, across six of the eight parameters used to measure disease severity, the infection in the vaccinated badgers was significantly less severe than in the control group. The BCG vaccine induced a significant protective effect in the badgers and the protective immunity was generated by subcutaneous and mucosal vaccination.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Vacuna BCG/administración & dosificación , Reservorios de Enfermedades/veterinaria , Mustelidae , Mycobacterium bovis/inmunología , Tuberculosis/veterinaria , Administración Oral , Animales , Bovinos , Recuento de Colonia Microbiana/veterinaria , Femenino , Irlanda , Pulmón/patología , Masculino , Membrana Mucosa/inmunología , Mycobacterium bovis/patogenicidad , Índice de Severidad de la Enfermedad , Tuberculosis/inmunología , Tuberculosis/prevención & control , Tuberculosis Bovina/prevención & control , Reino Unido
8.
Hum Mov Sci ; 25(2): 257-74, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16458382

RESUMEN

This study investigated the effects of unilateral grab rail assistance during the sit-to-stand transfer to develop an understanding of lower limb joint mechanics and whole body movement patterns. External reaction forces at the grab rail and floor interfaces were also investigated to understand the nature of the assistance provided by the introduction of unilateral upper body assistance. While 12 older aged adults performed the sit-to-stand, three-dimensional body segment kinematics were recorded to determine lower body joint motion and whole body centre of mass motion. Grab rail reaction forces and bilateral ground reaction forces were recorded to determine external reaction forces and lower body joint kinetics. Grab rail assisted conditions were compared with unassisted transfers. During grab rail assistance, a systematic asymmetry was introduced to lower limb joint kinetics, without noticeable alterations to peak lower body joint motion and whole body movement patterns. Ipsilateral net joint moments and powers decreased in the ankle and hip and increased in the knee, while the contralateral net joint moments and powers increased in the hip and decreased in the knee. Joint kinetic and kinematic responses suggest a motor control strategy that maintains symmetric sit-to-stand movement patterns by adjusting bilateral muscle control when a unilateral external reaction force is provided. Understanding the mechanical assistance that is generated during the sit-to-stand will facilitate optimal design of grab rails for older aged adults and may contribute to design for specific pathologies. Such design implementation will influence the ability of older aged adults to remain independent in the community.


Asunto(s)
Fenómenos Biomecánicos , Articulaciones/fisiología , Movimiento/fisiología , Postura/fisiología , Caminata/fisiología , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Envejecimiento , Peso Corporal , Lateralidad Funcional , Humanos , Estrés Mecánico
9.
J Appl Biomech ; 21(1): 57-71, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16131705

RESUMEN

The aim of this study was to compare the effects of grab rail position, orientation, and number of hands used on the kinetics of assisted sit-to-stand transfers. Participants were 12 able-bodied older adults between the ages of 69 and 88 years. While each one performed the sit-to-stand transfer, a motion analysis system with 9 cameras recording at 60 Hz tracked the 3-D trajectories of retroreflective markers. Bilateral 37-D platform, grab rail, and seat force data were collected at 200 Hz and normalized to participant body weight. Four lateral conditions were tested: vertical, 45 degrees inclined, and horizontal with the hand placed at 150 mm and 400 mm forward of the seat front edge. Four anterior conditions were tested: vertical and horizontal orientations with the use of one hand and two hands. Posterior grab rail force increased with anterior assistance and with two-hand use compared to lateral assistance and single hand use, respectively. The selection of grab rail position and the number of hands incorporated during assistance also determined the symmetry of anteroposterior net joint forces, net joint moments, and joint powers. Grab rail orientation determined the height of the gripping hand which influenced the assistance strategy. Grab rail position, orientation, and the amount of upper body contribution influenced the assisted sit-to-stand transfer. These kinetic responses to grab rail location require careful consideration in order to optimize grab rail assistance during the sit-to-stand transfer.


Asunto(s)
Fuerza de la Mano/fisiología , Mano/fisiología , Articulaciones/fisiología , Pierna/fisiología , Movimiento/fisiología , Postura/fisiología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino
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