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1.
Epilepsia ; 64(6): 1466-1468, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36756707

RESUMO

The Critical Success Index (CSI) and Gilbert Skill score (GS) are verification measures that are commonly used to check the accuracy of weather forecasting. In this article, we propose that they can also be used to simplify the joint interpretation of positive predictive value (PPV) and sensitivity estimates across diagnostic accuracy studies of epilepsy data. This is because CSI and GS each provide a single measure that takes the weather forecasting equivalent of PPV and sensitivity into account. We have re-analysed data from our recent systematic review of diagnostic accuracy studies of administrative epilepsy data using CSI and GS. We summarise the results and benefits of this approach.


Assuntos
Epilepsia , Humanos , Valor Preditivo dos Testes , Epilepsia/diagnóstico , Previsões , Tempo (Meteorologia) , Sensibilidade e Especificidade
2.
J Immunol ; 206(12): 3073-3082, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34099545

RESUMO

ChipCytometry is a multiplex imaging method that can be used to analyze either cell suspensions or tissue sections. Images are acquired by iterative cycles of immunostaining with fluorescently labeled Abs, followed by photobleaching, which allows the accumulation of multiple markers on a single sample. In this study, we explored the feasibility of using ChipCytometry to identify and phenotype cell subsets, including rare cell types, using a combination of tissue sections and single-cell suspensions. Using ChipCytometry of tissue sections, we successfully demonstrated the architecture of human palatine tonsils, including the B and T cell zones, and characterized subcompartments such as the B cell mantle and germinal center zone, as well as intrafollicular PD1-expressing CD4+ T cells. Additionally, we were able to identify the rare tonsillar T cell subsets, mucosal-associated invariant T (MAIT) and γδ-T cells, within tonsil tissue. Using single-cell suspension ChipCytometry, we further dissected human tonsillar T cell subsets via unsupervised clustering analysis as well as supervised traditional manual gating. We were able to show that PD1+CD4+ T cells are comprised of CXCR5+BCL6high follicular Th cells and CXCR5-BCL6mid pre-follicular Th cells. Both supervised and unsupervised analysis approaches identified MAIT cells in single-cell suspensions, confirming a phenotype similar to that of blood-derived MAIT cells. In this study, we demonstrate that ChipCytometry is a viable method for single-cell suspension cytometry and analysis, with the additional benefit of allowing phenotyping in a spatial context using tissue sections.


Assuntos
Centro Germinativo , Tonsila Palatina , Linfócitos B , Humanos , Subpopulações de Linfócitos T , Linfócitos T Auxiliares-Indutores
3.
J Sports Sci ; 41(2): 172-180, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37102421

RESUMO

The current study explored the association between talent pool size and relative age effects in Football Australia's talent pathway. It also compared relative age effects between male and female players. Participants were 54,207 youth football players (females: n = 12,527, age-range = 14.0-15.9; males: n = 41,680, age-range = 13.0-14.9) eligible for the National Youth Championships. We developed linear regression models to examine the association between the member federation size and the probability of a player being born earlier in the year. We also analysed selection probabilities based on birth quartile and year half across three layers. Overall, talent pool size was associated with a higher probability of selecting a player born in the first half of the year over the second. More specifically, an increase of 760 players led to a 1% higher selection probability for those born in the first six months of a chronological age group. In addition, there were more occurrences of relative age effects in the male than the female sample. Future studies should focus on the impact of the talent pool size on relative age effects at each major talent identification/selection stage of a talent pathway.


Assuntos
Desempenho Atlético , Futebol , Adolescente , Feminino , Humanos , Masculino , Fatores Etários , Aptidão , Austrália , Prevalência
4.
Knee Surg Sports Traumatol Arthrosc ; 31(12): 5950-5961, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37989778

RESUMO

PURPOSE: The purposes of this study are to, firstly, develop techniques to accurately identify extensor mechanism malalignment by measuring the alignment of the quadriceps tendon (QTA) with computerized tomography (CT) scans. Secondly, to investigate correlations between QTA and lower limb bony anatomical variations within a representative normal population. Lastly, to evaluate the clinical significance of QTA by establishing its potential connection with lateral facet patellofemoral joint osteoarthritis (LFPFJOA). METHOD: CT scans were orientated to a mechanical axis reference frame and three techniques developed to measure the alignment of the quadriceps tendon. Multiple measurement of bony alignment from the hip to the ankle were performed on each scan. A series of 110 cadaveric CT scans were measured to determine normal values, reproducibility, and correlations with bony anatomy. Secondly, a comparison between 2 groups of 25 patients, 1 group with LFPFJOA and 1 group with isolated medial OA and no LFPFJOA. RESULTS: From the cadaveric study, it was determined that the alignment of the quadriceps tendon is on average 4.3° (SD 3.9) varus and the apex of the tendon is 9.1 mm (SD 7.7 mm) lateral to the trochlear groove and externally rotated 1.9° (SD 12.4°) from the centre of the femoral shaft. There was no association between the quadriceps tendon alignment and any other bony measurements including tibial tubercle trochlear groove distance (TTTG), coronal alignment, trochlear groove alignment and femoral neck anteversion. A lateralized QTA was significantly associated with LFPFJOA. QTA in the LFPFJOA group was 9.6° varus (SD 2.8°), 21.3 mm (SD 6.6) lateralised and 17.3° ER (SD 11°) compared to 5.5° (SD 2.3°), 10.7 mm (SD 4.9) and 3.3° (SD 7.2°), respectively, in the control group (p < 0.001). A significant association with LFPFJOA was also found for TTTG (17.2 mm (SD 5.7) vs 12.1 mm (SD 4.3), p < 0.01). Logistic regression analysis confirmed the QTA as having the stronger association with LFPFJOA than TTTG (AUC 0.87 to 0.92 for QTA vs 0.79 for TTTG). CONCLUSION: These studies have confirmed the ability to accurately determine QTA on CT scans. The normal values indicate that the QTA is highly variable and unrelated to bony anatomy. The comparative study has determined that QTA is clinically relevant and a lateralised QTA is the dominant predictor of severe LFPFJOA. This deformity should be considered when assessing patella maltracking associated with patella osteoarthritis, patella instability and arthroplasty. LEVEL OF EVIDENCE: III (retrospective cohort study).


Assuntos
Osteoartrite , Articulação Patelofemoral , Humanos , Articulação Patelofemoral/diagnóstico por imagem , Articulação Patelofemoral/cirurgia , Estudos Retrospectivos , Reprodutibilidade dos Testes , Tíbia/cirurgia , Patela , Tendões , Cadáver , Articulação do Joelho/cirurgia
5.
Biol Sport ; 40(4): 1003-1017, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37867748

RESUMO

Due to the lack of research in real-world sports competitions, the International Olympic Committee, in 2012, called for data characterising athletes' sport and event-specific thermal profiles. Studies clearly demonstrate that elite athletes often attain a core body temperature (Tc) ≥ 40°C without heat-related medical issues during competition. However, practitioners, researchers and ethical review boards continue to cite a Tc ≥ 40°C (and lower) as a threshold where athlete health is impacted (an assumption from laboratory studies). Therefore, this narrative review aims to: (i) summarise and review published data on Tc responses during competitive sport and identify key considerations for practitioners; (ii) establish the incidence of athletes experiencing a Tc ≥ 40°C in competitive sport alongside the incidence of heat illness/heat stroke (EHI/EHS) symptoms; and (iii) discuss the evolution of Tc measurement during competition. The Tc response is primarily based on the physical demands of the sport, environmental conditions, competitive level, and athlete disability. In the reviewed research, 11.9% of athletes presented a Tc ≥ 40°C, with only 2.8% of these experiencing EHI/EHS symptoms, whilst a high Tc ≥ 40°C (n = 172; Tc range 40-41.5°C) occurred across a range of sports and environmental conditions (including some temperate environments). Endurance athletes experienced a Tc ≥ 40°C more than intermittent athletes, but EHI/EHS was similar. This review demonstrates that a Tc ≥ 40°C is not a consistently meaningful risk factor of EHI/EHS symptomology in this sample; therefore, Tc monitoring alongside secondary measures (i.e. general cognitive disturbance and gait disruption) should be incorporated to reduce heat-related injuries during competition.

6.
J Sports Sci ; 40(6): 667-695, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34967269

RESUMO

Talent identification in youth soccer is a complex decision-making process that requires selectors to judge an individual's future potential. While there has been considerable research into the performance characteristics of talented players, investigators have limited consensus on the best approach to assess soccer skills. Most of the research explains why we should measure skill instead of how we go about assessing skill. Therefore, the current scoping review aimed to synthesize and analyse skill assessments in youth soccer. Four electronic databases (EBSCO, ProQuest, PubMed, and Scopus) were searched for relevant studies. Information regarding the sample characteristics and methodological design of the skill assessments were extracted, synthesised, and presented in a qualitative analysis. Overall, 226 skill assessments were used across the 93 included studies. Male players from different ages (U/7-U/23) and playing levels comprised most (89%) of the collective sample. The majority of assessments were performed in settings not representative of football match-play (68%), focused on offensive skills (99%), and included skill outcome measures (95%). The variability of assessments highlights some confusion about the best way to assess soccer skill, potentially limiting selectors ability to identify skilful players. Ultimately, this will impact the number of quality players within the talent pool.


Assuntos
Desempenho Atlético , Futebol , Adolescente , Humanos , Masculino , Aptidão
7.
Epilepsia ; 61(7): 1319-1335, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32474909

RESUMO

Our objective was to undertake a systematic review ascertaining the accuracy of using administrative healthcare data to identify epilepsy cases. We searched MEDLINE and Embase from 01/01/1975 to 03/07/2018 for studies evaluating the diagnostic accuracy of routinely collected healthcare data in identifying epilepsy cases. Any disease coding system in use since the International Classification of Diseases, Ninth Revision (ICD-9) was permissible. Two authors independently screened studies, extracted data, and quality-assessed studies. We assessed positive predictive value (PPV), sensitivity, negative predictive value (NPV), and specificity. The primary analysis was a narrative synthesis of review findings. Thirty studies were included, published between 1989 and 2018. Risks of bias were low, high, and unclear in 4, 14, and 12 studies, respectively. Coding systems included ICD-9, ICD-10, and Read Codes, with or without antiepileptic drugs (AEDs). PPVs included ranges of 5.2%-100% (Canada), 32.7%-96.0% (USA), 47.0%-100% (UK), and 37.0%-88.0% (Norway). Sensitivities included ranges of 22.2%-99.7% (Canada), 12.2%-97.3% (USA), and 79.0%-94.0% (UK). Nineteen studies contained at least one algorithm with a PPV >80%. Sixteen studies contained at least one algorithm with a sensitivity >80%. PPV was highest in algorithms consisting of disease codes (ICD-10 G40-41, ICD-9 345) in combination with one or more AEDs. The addition of symptom codes to this (ICD-10 R56; ICD-9 780.3, 780.39) lowered PPV. Sensitivity was highest in algorithms consisting of symptom codes with one or more AEDs. Although using AEDs alone achieved high sensitivities, the associated PPVs were low. Most NPVs and specificities were >90%. We conclude that it is reasonable to use administrative data to identify people with epilepsy (PWE) in epidemiological research. Studies prioritizing high PPVs should focus on combining disease codes with AEDs. Studies prioritizing high sensitivities should focus on combining symptom codes with AEDs. We caution against the use of AEDs alone to identify PWE.


Assuntos
Coleta de Dados/estatística & dados numéricos , Bases de Dados Factuais/estatística & dados numéricos , Atenção à Saúde/estatística & dados numéricos , Epilepsia/epidemiologia , Estudos de Validação como Assunto , Coleta de Dados/normas , Bases de Dados Factuais/normas , Atenção à Saúde/normas , Epilepsia/diagnóstico , Humanos
8.
Epilepsy Behav ; 110: 107119, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32526686

RESUMO

PURPOSE: The purpose of the present study was to investigate the relationship between subcortical nuclei volume and cognition in children with post-convulsive status epilepticus (CSE). METHODS: Structural T1-weighted magnetic resonance imaging (MRI) scans (Siemens Avanto, 1.5 T) and neuropsychological assessments (full-scale intelligence quotient (FSIQ) and Global Memory Scores (GMS)) were collected from subjects at a mean 8.5 years post-CSE (prolonged febrile seizures (PFS), n = 30; symptomatic/known, n = 28; and other, n = 12) and from age- and sex-matched healthy controls (HC). Subjects with CSE were stratified into those with lower cognitive ability (LCA) (CSE+, n = 22) and those without (CSE-, n = 48). Quantitative volumetric analysis using Functional MRI of the Brain Software Library (FSL) (Analysis Group, FMRIB, Oxford) provided segmented MRI brain volumes. Univariate analysis of covariance (ANCOVA) was performed to compare subcortical nuclei volumes across subgroups. Multivariable linear regression was performed for each subcortical structure and for total subcortical volume (SCV) to identify significant predictors of LCA (FSIQ <85) while adjusting for etiology, age, socioeconomic status, sex, CSE duration, and intracranial volume (ICV); Bonferroni correction was applied for the analysis of individual subcortical nuclei. RESULTS: Seventy subjects (11.8 ±â€¯3.4 standard deviation (SD) years; 34 males) and 72 controls (12.1 ±â€¯3.0SD years; 29 males) underwent analysis. Significantly smaller volumes of the left thalamus, left caudate, right caudate, and SCV were found in subjects with CSE+ compared with HC, after adjustment for intracranial, gray matter (GM), or cortical/cerebellar volume. When compared with subjects with CSE-, subjects with CSE+ also had smaller volumes of the left thalamus, left pallidum, right pallidum, and SCV. Individual subcortical nuclei were not associated, but SCV was associated with FSIQ (p = 0.005) and GMS (p = 0.014). Intracranial volume and etiology were similarly predictive. CONCLUSIONS: Nine years post-CSE, SCV is significantly lower in children who have LCA compared with those that do not. However, in this cohort, we are unable to determine whether the relationship is independent of ICV or etiology. Future, larger scale studies may help tease this out.


Assuntos
Cérebro/diagnóstico por imagem , Cognição/fisiologia , Imageamento por Ressonância Magnética/tendências , Estado Epiléptico/diagnóstico por imagem , Estado Epiléptico/psicologia , Adolescente , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Cérebro/fisiologia , Criança , Estudos de Coortes , Feminino , Seguimentos , Globo Pálido/diagnóstico por imagem , Globo Pálido/fisiologia , Humanos , Testes de Inteligência , Imageamento por Ressonância Magnética/métodos , Masculino , Testes Neuropsicológicos , Tamanho do Órgão/fisiologia , Tálamo/diagnóstico por imagem , Tálamo/fisiologia
9.
J Med Internet Res ; 22(11): e16632, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33151158

RESUMO

BACKGROUND: Technology-assisted intervention and prevention strategies present opportunities for substance use-related research with emerging adults (EAs) and their peers. Emerging adulthood is a developmentally distinct period in which individuals between the ages of 18 and 29 years undergo unique emotional, cultural, developmental, and biological changes as they transition into adulthood. Crowdsourcing, or gathering feedback from a large group within web-based communities, offers researchers a unique and cost-effective way to obtain large amounts of information in a short period. OBJECTIVE: This paper presents market feedback obtained via Amazon's Mechanical Turk from EAs (N=458) on the acceptability and utility of brief intervention scripts for a smartphone app currently under development. The mobile app, Harbor, teaches friends of EAs with substance use problems effective and supportive strategies for helping their friend make changes in their substance use behavior. METHODS: We examined feedback on the wording of the intervention scripts and estimated the market size of EAs who may use this app. Furthermore, we calculated correlations between script ratings and measures of personal risky drinking (ie, Alcohol Use Disorder Identification Test) and the participants' use of confrontational, enabling, or supportive behaviors with an existing friend. RESULTS: Approximately half of our sample (208/458, 45.4%) indicated that they had a close friend for whom they had concerns about their substance use, suggesting a potentially high demand for an app such as Harbor. Initial findings suggest that peers who engage in less enabling behaviors with friends who have a substance use problem exhibited lower risky drinking behaviors overall (r206=-0.501; P<.001). Concerning acceptability, 98.0% (449/458) of the sample rated the scripts' dialogue as either somewhat, moderately, or extremely realistic (mean 3.92, SD 0.48) on 5-point Likert scale items. Finally, 95.4% (437/454) of respondents indicated that the scripts would be at least slightly helpful for training peers to help their friends with substance use issues. Finally, individuals who were better able to identify enabling language in enabling scripts self-reported fewer enabling behaviors toward their friend's substance use (r206=-0.236; P=.001). CONCLUSIONS: There exists a demonstrated level of desirability and acceptability among EAs for a mobile app such as Harbor. EAs who wish to engage in more supportive behaviors with their friends who engage in substance use and who are amenable to assisting their friends with sobriety likely would use and benefit from this app.


Assuntos
Aplicativos Móveis/normas , Transtornos Relacionados ao Uso de Substâncias/terapia , Adolescente , Adulto , Feminino , Amigos , Humanos , Masculino , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto Jovem
11.
J Strength Cond Res ; 33(1): 197-202, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28240713

RESUMO

Stevens, CJ, Bennett, KJM, Novak, AR, Kittel, AB, and Dascombe, BJ. Cycling power profile characteristics of national-level junior triathletes. J Strength Cond Res 33(1): 197-202, 2019-With the draft-legal rule recently introduced to junior triathlon competition, it has become difficult to assess cycling performance through race results. Therefore, this study assessed the cycling power profile characteristics of national-level junior triathletes to assist with physical assessment and program design. Thirteen male (17.0 ± 1.0 years) and 11 female (17.2 ± 1.3 years) national-level junior triathletes completed a cycling power profile that consisted of maximal intervals that lasted 6, 15, 30, 60, 240, and 600 seconds in duration. Each power profile was completed on a LeMond ergometer using the subject's own bicycle, with power output and cadence recorded for all intervals. Mean power output values for males (783 ± 134, 768 ± 118, 609 ± 101, 470 ± 65, 323 ± 38, and 287 ± 34 W) were significantly (p ≤ 0.05) higher than those for females (554 ± 92, 510 ± 89, 437 ± 75, 349 ± 56, 248 ± 39, and 214 ± 37 W) across all intervals, respectively. Peak power output values for males across the 6- and 15-second intervals (1,011 ± 178 and 962 ± 170 W) were also significantly higher than those for females (674 ± 116 and 624 ± 114 W), respectively (p ≤ 0.05). Developing junior triathletes should aim to increase their capacity across the power profile above the mean values listed. Athletes should further aim to have power outputs equal to that of the best performers and beyond to ensure that they can meet the demands of any competition situation.


Assuntos
Desempenho Atlético , Ciclismo/fisiologia , Adolescente , Antropometria , Atletas , Feminino , Frequência Cardíaca , Humanos , Masculino
12.
J Strength Cond Res ; 33(2): 538-543, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28570495

RESUMO

Novak, AR, Bennett, KJM, Pluss, MA, Fransen, J, Watsford, ML, and Dascombe, BJ. Power profiles of competitive and noncompetitive mountain bikers. J Strength Cond Res 33(2): 538-543, 2019-The performance of Olympic distance cross-country mountain bikers (XCO-MTB) is affected by constraints such as erosion of track surfaces and mass start congestion which can affect race results. Standardized laboratory assessments quantify interseasonal and intraseasonal cycling potential through the assessment of multiple physiological capacities. Therefore, this study examined whether the power profile assessment (PPA) could discriminate between competitive XCO-MTB and noncompetitive mountain bikers (NC-MTB). Second, it aimed to report normative power profile data for competitive XCO-MTB cyclists. Twenty-nine male participants were recruited across groups of XCO-MTB (n = 14) and NC-MTB (n = 15) mountain bikers. Each cyclist completed a PPA that consisted of increasing duration maximal efforts (6, 15, 30, 60, 240, and 600 seconds) that were interspersed by longer rest periods (174, 225, 330, 480, and 600 seconds) between efforts. Normative power outputs were established for XCO-MTB cyclists ranging between 13.8 ± 1.5 W·kg (5-second effort) and 4.1 ± 0.6 W·kg (600-second effort). No differences in absolute peak power or cadence were identified between groups across any effort length (p > 0.05). However, the XCO-MTB cyclists produced greater mean power outputs relative to body mass than the NC-MTB during the 60-second (6.9 ± 0.8 vs 6.4 ± 0.6 W·kg; p = 0.002), 240-second (4.7 ± 0.7 vs. 3.8 ± 0.4 W·kg; p < 0.001), and 600-second (4.1 ± 0.6 vs. 3.4 ± 0.3 W·kg; p < 0.001) efforts. The PPA is a useful discriminative assessment tool for XCO-MTB and highlights the importance of aerobic power for XCO-MTB performance.


Assuntos
Atletas , Ciclismo/fisiologia , Adulto , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto Jovem
13.
J Sports Sci ; 36(22): 2537-2543, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29695189

RESUMO

There is limited research in talent identification in youth Australian Football (AF), especially the factors that underpin selection into higher-level development programs. Therefore, this study explored age-related differences in high-level youth AF players and investigated characteristics influencing selection into a high-level development program. Anthropometry (stature, sitting height, body mass), maturity (estimated age at peak height velocity), motor competence (Körperkoordinationstest für Kinder), fitness (change of direction speed, lower body power and upper body muscular endurance) and coach skill ratings (kicking, marking and handballing) of 277 state academy players (U13-U15) were assessed. MANOVAs identified significant age-related differences for anthropometry, fitness, and coach skill ratings. Furthermore, 90.9 and 90.0% of U15 selected and deselected players were classified correctly. Selected players were more mature, taller, heavier, more explosive, faster at changing directions, and had superior kick technique and marking results. These results demonstrate considerable age-group performance outcome differences, highlighting that high-level academies should aim to select or deselect after 15 years of age. Additionally, it appears earlier maturing players are favoured for selection into a high-level academy. While practitioners must consider the confounding effect of maturation, early maturing players may be favoured for their ability to withstand increasing demands in higher-level youth AF.


Assuntos
Aptidão , Futebol/fisiologia , Futebol/psicologia , Adolescente , Fatores Etários , Antropometria , Austrália , Criança , Estudos Transversais , Humanos , Tutoria , Destreza Motora , Aptidão Física , Maturidade Sexual
14.
J Sports Sci ; 36(1): 71-78, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28103737

RESUMO

This study adopted a multidimensional approach to performance prediction within Olympic distance cross-country mountain biking (XCO-MTB). Twelve competitive XCO-MTB cyclists (VO2max 60.8 ± 6.7 ml · kg-1 · min-1) completed an incremental cycling test, maximal hand grip strength test, cycling power profile (maximal efforts lasting 6-600 s), decision-making test and an individual XCO-MTB time-trial (34.25 km). A hierarchical approach using multiple linear regression analyses was used to develop predictive models of performance across 10 circuit subsections and the total time-trial. The strongest model to predict overall time-trial performance achieved prediction accuracy of 127.1 s across 6246.8 ± 452.0 s (adjusted R2 = 0.92; P < 0.01). This model included VO2max relative to total cycling mass, maximal mean power across 5 and 30 s, peak left hand grip strength, and response time for correct decisions in the decision-making task. A range of factors contributed to the models for each individual subsection of the circuit with varying predictive strength (adjusted R2: 0.62-0.97; P < 0.05). The high prediction accuracy for the total time-trial supports that a multidimensional approach should be taken to develop XCO-MTB performance. Additionally, individual models for circuit subsections may help guide training practices relative to the specific trail characteristics of various XCO-MTB circuits.


Assuntos
Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Teste de Esforço/métodos , Adulto , Antropometria , Tomada de Decisões , Força da Mão , Humanos , Modelos Lineares , Masculino , Consumo de Oxigênio
15.
J Sports Sci ; 36(4): 462-468, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28406361

RESUMO

This study aimed to cross validate previously developed predictive models of mountain biking performance in a new cohort of mountain bikers during a 4-h event (XC4H). Eight amateur XC4H cyclists completed a multidimensional assessment battery including a power profile assessment that consisted of maximal efforts between 6 and 600 s, maximal hand grip strength assessments, a video-based decision-making test as well as a XC4H race. A multiple linear regression model was found to predict XC4H performance with good accuracy (R2 = 0.99; P < 0.01). This model consisted of [Formula: see text] relative to total cycling mass (body mass including competition clothing and bicycle mass), maximum power output sustained over 60 s relative to total cycling mass, peak left hand grip strength and two-line decision-making score. Previous models for Olympic distance MTB performance demonstrated merit (R2 = 0.93; P > 0.05) although subtle changes improved the fit, significance and normal distribution of residuals within the model (R2 = 0.99; P < 0.01), highlighting differences between the disciplines. The high level of predictive accuracy of the new XC4H model further supports the use of a multidimensional approach in predicting MTB performance. The difference between the new, XC4H and previous Olympic MTB predictive models demonstrates subtle differences in physiological requirements and performance predictors between the two MTB disciplines.


Assuntos
Ciclismo/fisiologia , Destreza Motora/fisiologia , Resistência Física/fisiologia , Adulto , Índice de Massa Corporal , Tomada de Decisões , Força da Mão/fisiologia , Humanos , Modelos Lineares
16.
Res Sports Med ; 26(3): 276-288, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29506423

RESUMO

The objective of this study was to investigate knee muscle strength characteristics in players from a high-level youth football Academy. In total, 110 players (aged 8-15 years) underwent muscle strength assessments carried out by a research physiotherapist using a computer-linked hand-held dynamometer. Results indicated that isometric hamstrings and quadriceps strength increased with age, whereas the isometric hamstring to quadriceps (H/Q) ratio decreased with age. A number of youth football players (n = 20; 18%; 95% CI: 11-27%) demonstrated isometric H/Q ratios of less than 0.60, as well as muscle strength asymmetries between limbs for the hamstrings (n = 40, 36%; 95% CI: 27-46%) and quadriceps (n = 51, 46%; 95% CI 37-56%), potentially increasing injury risk. This study provides new evidence that the isometric H/Q ratio reduces with advancing age during adolescence which may have important implications for junior athlete development and long-term injury prevention in football.


Assuntos
Músculos Isquiossurais/fisiologia , Força Muscular , Músculo Quadríceps/fisiologia , Futebol , Adolescente , Atletas , Austrália , Criança , Estudos Transversais , Humanos , Masculino , Dinamômetro de Força Muscular
17.
J Strength Cond Res ; 31(3): 620-629, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27379961

RESUMO

Stevens, CJ, Bennett, KJM, Sculley, DV, Callister, R, Taylor, L, and Dascombe, BJ. A comparison of mixed-method cooling interventions on preloaded running performance in the heat. J Strength Cond Res 31(3): 620-629, 2017-The purpose of this investigation was to assess the effect of combining practical methods to cool the body on endurance running performance and physiology in the heat. Eleven trained male runners completed 4 randomized, preloaded running time trials (20 minutes at 70% V[Combining Dot Above]O2max and a 3 km time trial) on a nonmotorized treadmill in the heat (33° C). Trials consisted of precooling by combined cold-water immersion and ice slurry ingestion (PRE), midcooling by combined facial water spray and menthol mouth rinse (MID), a combination of all methods (ALL), and control (CON). Performance time was significantly faster in MID (13.7 ± 1.2 minutes; p < 0.01) and ALL (13.7 ± 1.4 minutes; p = 0.04) but not PRE (13.9 ± 1.4 minutes; p = 0.24) when compared with CON (14.2 ± 1.2 minutes). Precooling significantly reduced rectal temperature (initially by 0.5 ± 0.2° C), mean skin temperature, heart rate and sweat rate, and increased iEMG activity, whereas midcooling significantly increased expired air volume and respiratory exchange ratio compared with control. Significant decreases in forehead temperature, thermal sensation, and postexercise blood prolactin concentration were observed in all conditions compared with control. Performance was improved with midcooling, whereas precooling had little or no influence. Midcooling may have improved performance through an attenuated inhibitory psychophysiological and endocrine response to the heat.


Assuntos
Desempenho Atlético/fisiologia , Temperatura Corporal/fisiologia , Crioterapia/métodos , Temperatura Alta/efeitos adversos , Corrida/fisiologia , Adulto , Regulação da Temperatura Corporal/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física/fisiologia , Temperatura Cutânea , Água
18.
J Sports Sci ; 34(16): 1542-6, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26651383

RESUMO

This study examined the skill involvements of three positional groups across a junior representative rugby league season. Data were collected from 45 rugby league players (mean ± SD; age = 16.5 ± 1.0 years) currently participating in the Harold Matthews and SG Ball Cup. Players were subdivided into hit-up forwards, adjustables and outside backs. The frequency (n · min(-1)) of offensive, defensive and overall involvements was coded for each group using a notation system and a practical coach skill analysis tool. Multivariate analysis of variance (MANOVA) revealed a significant effect of playing position on skill involvements (F = 9.06; P < 0.001; ES = 0.41). Hit-up forwards performed a significantly greater frequency of offensive (0.31 ± 0.10), defensive (0.42 ± 0.15) and overall involvements (0.74 ± 0.19) when compared to adjustables (0.20 ± 0.08, 0.28 ± 0.08 and 0.52 ± 0.15, respectively) and outside backs (0.20 ± 0.12, 0.11 ± 0.07 and ± 0.31 ± 0.17, respectively). Further, adjustables performed a significantly greater number of defensive (0.28 ± 0.08) and overall involvements (0.52 ± 0.15) when compared to outside backs (0.11 ± 0.07 and 0.31 ± 0.17, respectively). The findings of this study suggest that it is important to consider a junior player's positional group when analysing their skill involvements. Information gained from this study could assist in the design of specific training methodologies for junior rugby league players in high-level talent development programmes.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Futebol Americano/fisiologia , Destreza Motora/fisiologia , Adolescente , Humanos , Análise e Desempenho de Tarefas
19.
J Cardiothorac Vasc Anesth ; 29(4): 955-66, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25753765

RESUMO

OBJECTIVE: To compare the efficacy and adverse effects of using bronchial blockers (BBs) and double-lumen endobronchial tubes (DLTs). DESIGN: Systematic review and meta-analysis of randomized controlled trials (RCTs) comparing BBs and DLTs. SETTING: Hospital units undertaking thoracic surgery PARTICIPANTS: Patients undergoing thoracic surgery requiring lung isolation. INTERVENTIONS: BBs and DLTs. MEASUREMENTS AND MAIN RESULTS: A systematic literature search was conducted for RCTs comparing BBs and DLTs using Google Scholar, Ovid Medline, and Cochrane library databases up to October 2013. Inclusion criteria were RCTs comparing BBs and DLTs, intubation carried out by qualified anesthesiologists or trainee specialists, outcome measures relating to either efficacy or adverse effects. Studies that were inaccessible in English were excluded. Mantel-Haenszel fixed-effect meta-analysis of recurring outcome measures was performed using RevMan 5 software. The search produced 39 RCTs published between 1996 and 2013. DLTs were quicker to place (mean difference: 51 seconds, 95% confidence intervals [CI] 8-94 seconds; p = 0.02) and less likely to be incorrectly positioned (odds ratio [OR] 2.70; 95% CI 1.18-6.18, p = 0.02) than BBs. BBs were associated with fewer patients having a postoperative sore throat (OR 0.39, 95% CI: 0.23-0.68, p = 0.0009), less hoarseness (OR: 0.43,95%, CI 0.24-0.75, p = 0.003), and fewer airway injuries (OR 0.40, 95% CI 0.21-0.75, p = 0.005) than DLTs. CONCLUSION: While BBs are associated with a lower incidence of airway injury and a lower severity of injury, DLTs can be placed quicker and more reliably.


Assuntos
Intubação Intratraqueal/instrumentação , Intubação Intratraqueal/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Procedimentos Cirúrgicos Torácicos/instrumentação , Procedimentos Cirúrgicos Torácicos/métodos , Rouquidão/diagnóstico , Rouquidão/etiologia , Humanos , Intubação Intratraqueal/efeitos adversos , Faringite/diagnóstico , Faringite/etiologia , Procedimentos Cirúrgicos Torácicos/efeitos adversos , Resultado do Tratamento
20.
Sci Med Footb ; : 1-9, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38512014

RESUMO

This study aimed to explore the perceptual-cognitive characteristics of coaches as they assessed team performance in youth soccer. The primary focus was to investigate the alignment between coaches' subjective analyses of team behaviour and objective analyses, while also examining the relationship between coaches' gaze behaviour and their levels of coaching experience, particularly considering the potential differences that may exist among coaches with varying levels of experience. Sixty-five male and female adults with various soccer coaching experience (experienced, novice, other team sport experience, and non-team sport experience) watched five 4-minute videos and assessed team behaviour. These subjective evaluations were compared to objective data obtained from video analysis and GPS, which included measures of completed skills, spatiotemporal characteristics, and passing networks. The participants' fixation duration and frequency were measured for each video clip, and the area around the ball specifically. The study found no significant differences between groups regarding the number of times participants' subjective analysis aligned with the objective data (p = 0.059, ɳ2 = 0.07). However, coaches with soccer coaching experience demonstrated a higher fixation frequency and more revisits to the ball area when compared to participants without soccer experience (p = <.001, ɳ2 = 0.09). The current study offers a unique approach to uncovering soccer coaching expertise by combining objective and subjective evaluations of team performance. In summary, the study reveals that coaching experience did not impact how often coaches subjective analyses matched objective data. However, soccer coaches had distinctive gaze behaviour patterns where they revisited the area around the ball more often.


Coaches' perceptions of collective behaviour in soccer teams do not align with objective data, regardless of their level of coaching experience.Gaze behaviour differs between coaches with varying expertise levels.Both experienced and novice coaches visually revisit the area around the ball more often than non-coaches when assessing team performance.Quantitative data may provide an additional level of team analysis than subjective coach assessment alone.

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