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Breast displacement has been investigated in various activities to inform bra design, with the goal of minimising movement; however, breast motion during swimming has yet to be considered. The aim was to investigate trunk and breast kinematics whilst wearing varying levels of breast support during two swimming strokes. Six larger-breasted females swam front crawl and breaststroke (in a swimming flume), in three breast support conditions while three video cameras recorded the motion of the trunk and right breast. Trunk and relative breast kinematics were calculated. Greater breast displacement occurred mediolaterally in the swimsuit condition (7.8, s = 1.5 cm) during front crawl and superioinferiorly in the bare-breasted condition (3.7, s = 1.6 cm) during breaststroke, with the sports bra significantly reducing breast displacements. During front crawl, the greatest trunk roll occurred in the sports bra condition (43.1, s = 8.3°) and during breaststroke greater trunk extension occurred in the swimsuit condition (55.4, s = 5.0°); however, no differences were found in trunk kinematics between the three breast support conditions. Results suggest that the swimsuit was ineffective as a means of additional support for larger-breasted women during swimming; incorporating design features of sports bras into swimsuits may improve the breast support provided. 相似文献
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In the present study, we examined the independent and combined effects of an inspiratory muscle warm-up and inspiratory muscle training on intermittent running to exhaustion. Twelve males were recruited to undertake four experimental trials. Two trials (Trials 1 and 2) preceded either a 4-week training period of 1 × 30 breaths twice daily at 50% (experimental group) or 15% (control group) maximal inspiratory mouth pressure (PImax). A further two trials (Trials 3 and 4) were performed after the 4 weeks. Trials 2 and 4 were preceded by a warm-up: 2 × 30 breaths at 40% PImax. Pre-training PImax and distance covered increased (P < 0.05) similarly between groups after the warm-up (~11% and ~5-7% PImax and distance covered, respectively). After training, PImax increased by 20 ± 6.1% (P < 0.01; d = 3.6) and 26.7 ± 6.3% (P < 0.01; d = 3.1) when training and warm-up were combined in the experimental group. Distance covered increased after training in the experimental group by 12 ± 4.9% (P < 0.01; d = 3.6) and 14.9 ± 4.5% (P < 0.01; d = 2.3) when training and warm-up interventions were combined. In conclusion, inspiratory muscle training and inspiratory muscle warm-up can both increase running distance independently, but the greatest increase is observed when they are combined. 相似文献
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Public libraries have been seen to have an important role in providing digital services to potentially excluded groups in order to help meet government targets regarding the delivery of digital services. Geographical information systems (GIS) have been used to investigate library service areas, to aid initial location decisions, and to model the implications of the opening and closure of library services. Recent studies have promoted the use of GIS-based techniques to investigate spatial variations in accessibility to public and private services in relation to socio-economic characteristics of population groups. One such technique, based on floating catchment area (FCA) approaches, has been primarily used to investigate potential inequalities in health services, access to employment and leisure opportunities, as well as planning public transport. In this study, FCA techniques are used to research variations in accessibility to public library facilities using bespoke application tools developed within a commercial GIS package. Drawing on a preliminary analysis of variations in accessibility to library services in a local authority area in south Wales, UK, a case study is presented whereby GIS-based models can be used to investigate spatial variations in digital services provision. As a result, provision gaps of such services can be identified. This study's findings help guide national government delivery programs to promote digital inclusion. 相似文献
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Andrew Miller Narelle Eather Mitch Duncan David Revalds Lubans 《Journal of sports sciences》2019,37(2):173-179
This study investigated if object control relates to children’s game play competence, and examined these competencies as correlates of physical activity and cardiorespiratory fitness. Game play (Game Performance Assessment Instrument), object control (The Test Gross Motor Development-3), moderate-to-vigorous physical activity (Accelerometry), and cardiorespiratory fitness (20-metre shuttle) assessments were completed for 107 children (57% Female, 43% Male) aged 9–12 years (M 10.53, SD 0.65). Two-level regression of object control on game play competence, and object control and game play competence on physical activity and cardiorespiratory fitness assessed associations. Object control competence was positively associated with game play competence (Std. B = 0.25, t (104.77) = 2.38, p = 0.001). Game play competence (Std. B = 0.33, t (99.81) = 5.21, p < 0.000) was more strongly associated with moderate-to-vigorous physical activity than object control competence (Std. B = 0.20, t (106.93) = 2.96, p = 0.003). Likewise, game competence (Std. B = 0.39, t (104.41) = 4.36, p < 0.000) was more strongly associated with cardiorespiratory fitness than object control competence (Std. B = 0.22, t (106.69) = 2.63, p = 0.002). Object control and game competence are both important as correlates of physical activity and cardiorespiratory fitness in children. 相似文献
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The aim of this study was to investigate the effect of pre-induced inspiratory muscle fatigue (IMF) on race-paced swimming and acid-base status. Twenty-one collegiate swimmers performed two discontinuous 400-m race-paced swims on separate days, with (IMF trial) and without (control trial) pre-induced IMF. Swimming characteristics, inspiratory and expiratory mouth pressures, and blood parameters were recorded. IMF and expiratory muscle fatigue (P < 0.05) were evident after both trials and swimming time was slower (P < 0.05) from 150-m following IMF inducement. Pre-induced IMF increased pH before the swim (P < 0.01) and reduced bicarbonate (P < 0.05) and the pressure of carbon dioxide (PCO2) (P < 0.05). pH (P < 0.05), bicarbonate (P < 0.01) and PCO2 (P < 0.05) were lower during swimming in the IMF trial. Blood lactate was similar before both trials (P > 0.05) but was higher (P < 0.01) in the IMF trial after swimming. Pre-induced IMF induced respiratory alkalosis, reduced bicarbonate buffering capacity and slowed swimming speed. Pre-induced and propulsion-induced IMF reflected metabolic acidosis arising from dual role breathing and propulsion muscle fatigue. 相似文献
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Richard R. Rosenkranz Karly S. Geller Mitch J. Duncan Cristina M. Caperchione Corneel Vandelanotte Anthony J. Maeder 《Measurement in physical education and exercise science》2018,22(4):322-331
This cross-sectional study of 504 community-dwelling Australian adults (328 females, 176 males, mean age 50.8 ± 13.0 years) sought to examine the reliability and validity of measurement scales for physical activity (PA) self-efficacy and outcome expectations. Participants completed demographic and anthropometric measurements, and a 23-item psychosocial questionnaire pertinent to an intervention target of 10,000 steps per day. Exploratory (n = 252) and confirmatory (n = 252) factor analyses were conducted to determine psychometric properties of the measures. Based on theory and goodness-of-fit indices, six factors were extracted from the questionnaire: PA self-efficacy; PA barriers self-efficacy (including general, personal, and conflict); and physical and mental outcome expectations. From confirmatory factor analysis, the model demonstrated good data fit in four out of five indices: CFI = 0.99; TLI = 0.99; SRMR = 0.03; RMSEA = 0.03, 90%CI = 0.01–0.05, χ2 = 113.14 (88), p = 0.04; including good fit by sex, age, weight status, education, and birth country. PA interventions can employ our psychometrically sound social cognitive measures. 相似文献
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Mitch Parsell 《Ethics and Information Technology》2008,10(1):41-56
The importance of online social spaces is growing. New Web 2.0 resources allow the creation of social networks by any netizen
with minimal technical skills. These communities can be extremely narrowly focussed. In this paper, I identify two potential
costs of membership in narrowly focussed virtual communities. First, that narrowly focussed communities can polarise attitudes
and prejudices leading to increased social cleavage and division. Second, that they can lead sick individuals to revel in
their illness, deliberately indulging in their disease and denying the edicts of the medical profession. I specifically examine
illness communities centred on the now defunct Multiple Personality Disorder. I highlight these potential problems and point
to some technologies that may help combat them. 相似文献
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Paul E. Yeatts Mitch Barton Robin K. Henson Scott B. Martin 《Measurement in physical education and exercise science》2017,21(2):83-91
A common practice in general linear model (GLM) analyses is to interpret regression coefficients (e.g., standardized β weights) as indicators of variable importance. However, focusing solely on standardized beta weights may provide limited or erroneous information. For example, β weights become increasingly unreliable when predictor variables are correlated, which is often the case in the social sciences. To address this issue, structure coefficients, which are simply the bivariate correlation between a predictor and the synthetic ? variable, should also be interpreted. By examining β weights and structure coefficients in conjunction, the predictive worth of each independent variable can be more accurately judged. Despite this benefit, researchers in the field of sport and exercise science have rarely reported structure coefficients when conducting multiple regression analysis. Thus, the purpose of the present article is to discuss problems associated with the sole interpretation of β weights and to demonstrate how structure coefficients can be incorporated to improve accuracy of interpretation. Additionally, a content analysis was conducted to examine current trends in reporting multiple regression results within sport and exercise science research. 相似文献