Kinematic changes during learning the longswing on high bar     

Genevieve Williams  Gareth Irwin  David G. Kerwin  Karl M. Newell 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):20-33

The purpose of this study is to provide evidence of technique changes during learning a sports-specific skill, the looped bar longswing (LLS). Thirteen male participants with no previous high bar experience took part in a training study. Kinematic data were collected using a CODA motion analysis system (200 Hz) during eight weekly testing sessions. Analyses focused on the amplitude of swing and the functional phase (FP) actions, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical. Three groups were identified based on the number of sessions it took each participant to perform the LLS (G1: most successful, G2: intermediate, and G3: least successful). All participants were able to significantly increase swing amplitude over the training period (p < 0.05). For each participant the hip FP started significantly: later for G1, earlier for G2, and did not change for G3. Extension actions at the shoulders were dissimilar to those reported for elite gymnasts performing the longswing. The FP of the hips provides a mechanism to distinguish between the learners of different skill levels. The study has provided support for a single-subject design when investigating technique changes during learning.  相似文献   

Association of leisure time and occupational physical activity with obesity and cardiovascular risk factors in Chile     

Fanny Petermann-Rocha  Rosemary E. Brown  Ximena Diaz-Martínez  Ana M. Leiva  María A. Martinez  Felipe Poblete-Valderrama 《Journal of sports sciences》2013,31(22):2549-2559

ABSTRACT

The aim of this study was to investigate the association between physical activity (PA), both occupational (OPA) and during leisure time (LTPA), with obesity and cardiovascular risk factors in Chilean adults. 5,157 participants from the Chilean National Health Survey 2009–2010 were included in this study. OPA and LTPA levels were assessed using the Global Physical Activity Questionnaire. The association between both PA with obesity and cardiovascular risk factors was determined using logistic regression. Our findings showed a significant trend between higher LTPA and lower odds for obesity (OR 0.64 [95% CI: 0.53; 0.76], central obesity 0.52 [0.44; 0.61]) and other cardiovascular risk factors including diabetes (OR: 0.72 [0.55; 0.94]), hypertension (OR: 0.59 [0.50; 0.71]) and metabolic syndrome (OR: 0.62 [0.50; 0.78]). In contrast, OPA was only associated with lower odds of diabetes (OR: 0.79 [0.65; 0.98]) and hypertension (0.85 [0.74; 0.98]). In conclusion, LTPA was associated with a lower risk of all major cardiovascular risk factors, whereas OPA was only associated with a lower risk of diabetes and hypertension.  相似文献   

Optimized and corrected peak power output during friction‐braked cycle ergometry     

E.M. Winter  D. Brown  N.K.A. Roberts  F.B.C. Brookes  I.L. Swaine 《Journal of sports sciences》2013,31(6):513-521

Assessments of maximal intensity exercise which determine peak power output on friction‐baked cycle ergometers have fallen into two categories: correction procedures which account for changes in momentum of the ergometer's flywheel and optimization procedures which attempt to satisfy muscle force‐velocity relationships. The aim of this study was to compare performance in each procedure and so investigate assumptions which underpin the tests. Nineteen males aged 20.9 ± 0.4 years and 18 females aged 22.2 ± 0.7 years (mean ± S.E.M.), who were fully accustomed to the procedures, participated in a single experimental protocol. After a 5 min warm‐up, the subjects performed four bouts of all‐out exercise on a Monark 814E cycle ergometer against randomly assigned loads. The loads were selected to produce peak pedalling rates in the range 100–200 rev min^?1 and each bout lasted 10 s. From the inverse linear relationship between applied load and peak pedalling rate, optimized peak power output (PP _opt) and the accompanying pedalling rate (RPM _opt) were calculated. One of the bouts used a loading equivalent to 7.5% of body weight and for this bout corrected peak power output (PP _corr) and its corresponding pedalling rate (RPM _corr) were calculated. The PP _opt was less than PP _corr in the males (915 ± 35 vs 1005 ± 32 W) and females (673 ± 33 vs 777 ± 39 W) (both P < 0.001). Similarly, RPM _opt was less than RPM _corr (111 ± 1 vs 128 ± 2 rev min^?1 and 101 ± 1 vs 111 ± 2 rev min^?1 in the males and females, respectively; P < 0.001). The results demonstrate that optimization and correction procedures produce different values of performance. These differences are probably attributable to the mechanical principles which underpin the tests.  相似文献   

Response Time Comparisons among Four Base Running Starting Techniques in Slow Pitch Softball     

Richard G. Israel  Rodney L. Brown 《Research quarterly for exercise and sport》2013,84(3):324-329

Abstract

The purpose of this study was to compare response times among four starting techniques—cross-over step, jab-step, standing sprinter's start, and the momentum start—to determine the fastest start for optimum speed in base running in slow pitch softball. The subjects were 30 adult male amateur softball players. Response time was recorded to the nearest 1/100 second using a Dekan Automatic Performance Analyzer arranged with two starting lights and a stop gate. A one way repeated measures ANOVA indicated that the momentum start was significantly (p < .01) faster than the other starts compared while there were no significant differences among the other starts. Reliability coefficients ranging from .90 to .95, obtained using the intraclass correlation coefficient for multiple trial data, signified no trends among trials and high reliability of the testing procedures and equipment. The results suggested that the momentum start was the fastest starting technique for optimum speed for running bases in slow pitch softball.  相似文献   

Effects of Two Systems of Weight Training on Circulorespiratory Endurance and Related Physiological Factors     

Francis J. Nagle  Leslie W. Irwin 《Research quarterly for exercise and sport》2013,84(4):607-615

Abstract

Three groups, two experimental and one control, consisting of 20 college freshmen in each group, were tested doing moderate and all-out exercise on a bicycle ergometer. Selected physiological responses and the circulorespiratory endurance times were measured. An eight-week training period followed during which the experimental groups participated in weight-training programs and the control subjects in archery or bait casting. After training, the tests were again administered.

Though there was an indication of improved circulorespiratory responses by the weight-training groups following training, statistical treatment of the data revealed no significant differences among the three groups in their responses to exercise.  相似文献   

Musculoskeletal ultrasound training encourages self-directed learning and increases confidence for clinical and anatomical appreciation of first-year medical students     

Casey C. Brown  Shalynn D. Arrington  Jay F. Olson  Charles A. Finch Jr  Randall L. Nydam 《Anatomical sciences education》2022,15(3):508-521

Best-practice guidelines have incorporated ultrasound in diagnostic and procedural medicine. Due to this demand, the Arizona College of Osteopathic Medicine initiated a comprehensive integration of ultrasound into its first-year anatomy course attended by more than 280 students. Ultrasound workshops were developed to enhance student conceptualization of musculoskeletal (MSK) anatomy through visualizing clinically important anatomical relationships, a simulated lumbar puncture during the back unit, carpal tunnel and shoulder evaluations during the upper limb unit, and plantar fascia, calcaneal tendon, and tarsal tunnel evaluations during the lower limb unit. A 5-point Likert scale survey evaluated if ultrasound improved students' self-perceived anatomical and clinical comprehension of relevant anatomy, improved students' ability to orient to ultrasound imagery, and prompted further independent investigation of the anatomical area. Ultrasound examination questions were added to the anatomy examinations. Two-tailed one-sample t-tests for the back, upper limb, and lower limb units were found to be significant across all Likert survey categories (P < 0.001). Positive student responses to the Likert survey in conjunction with examination question average of 84.3% (±10.3) demonstrated that the ultrasound workshops are beneficial to student education. Ultrasound enhances medical students' clinical and anatomical comprehension and ability to orient to ultrasound imagery for MSK anatomy. This study supports early ultrasound education as a mechanism to encourage students' independent learning as evidenced by many undertaking voluntary investigation of clinical concerns associated with MSK anatomy. This study establishes the successful integration of MSK ultrasound into a large medical school program and its benefit to student clinical education.  相似文献   

A multicultural,gender, and sexually diverse affirming school-based consultation framework     

Jeffrey M. Brown  Shereen C. Naser  Charity Brown Griffin  Sally L. Grapin  Sherrie L. Proctor 《Psychology in the schools》2022,59(1):14-33

Gender and sexually diverse (GSD) students face unique challenges in schools due to the privileging of cisgender and heterosexist norms in these settings. In particular, GSD youth who belong to ethnically and racially minoritized groups face further challenges within school environments that disregard their cultural contexts and intersectional identities. It is important for school psychologists to ensure safe and high-quality mental health, educational, and behavioral supports for these students. One possible avenue for building these types of supports is through school consultation. When school psychologists collaborate with other professionals in a culturally competent, participatory way, their work has the potential to bolster behavioral, academic, and mental health outcomes at the individual, group, and/or systems levels. Adapting Ingraham's multicultural school consultation model, this article proposes a multicultural, GSD affirming school consultation framework that also approaches the experiences of racially and ethnically minoritized individuals through the lenses of intersectionality and minority stress frameworks. Across its five domains, this adapted framework aims to give practitioners and researchers a conceptual foundation to support GSD students of minoritized ethnic and racial identities by considering interactions among consultants, consultees, and clients within their wider school contexts.  相似文献   

Response to ‘Reply to Van Zandvoort,Tucker, Irwin and Burke: Physical activity at daycare: issues,challenges and perspectives’ by Albon     

Melissa van Zandvoort  Patricia Tucker  Jennifer D. Irwin  Shauna M. Burke 《Early Years: An International Journal of Research and Development》2011,31(2)

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Comparing patrons' renewal behavior before and after implementing more permissive loan rules     

Ken Irwin 《Journal Of Access Services》2016,13(4):237-246

This article reports on a study of how long library patrons at 28 college and university libraries kept books checked out before and after a policy change allowing for longer circulation periods and more renewals. The behavior of most patrons remained similar before and after the policy change, with only a slight (7–14 day) lengthening of the length of circulation for many patrons. A significant minority of patrons made more extensive use of the longer loan periods, demonstrating the usefulness of the policy change for many users.  相似文献   

Religious Climate     

William Irwin  Read Mercer Schuchardt 《Academic Questions》2017,30(1):83-83

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