Differences among fastball,curveball, and change-up pitching biomechanics across various levels of baseball     

Glenn S. Fleisig  Walter A. Laughlin  Kyle T. Aune  E. Lyle Cain  Jeffrey R. Dugas  James R. Andrews 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(2):128-138

Controversy continues whether curveballs are stressful for young baseball pitchers. Furthermore, it is unproven whether professional baseball pitchers have fewer kinematic differences between fastballs and off-speed pitches than lower level pitchers. Kinematic and kinetic data were measured for 111 healthy baseball pitchers (26 youth, 21 high school, 20 collegiate, 26 minor league, and 18 major league level) throwing fastballs, curveballs, and change-ups in an indoor biomechanics laboratory with a high-speed, automated digitising system. Differences between pitch types and between competition levels were analysed with repeated measures ANOVA. Shoulder and elbow kinetics were greater in fastballs than in change-ups, while curveball kinetics were not different from the other two types of pitches. Kinematic angles at the instant of ball release varied between pitch types, while kinematic angles at the instant of lead foot contact varied between competition levels. There were no significant interactions between pitch type and competition level, meaning that kinetic and kinematic differences between pitch types did not vary by competition level. Like previous investigations, this study did not support the theory that curveballs are relatively more stressful for young pitchers. Although pitchers desire consistent kinematics, there were differences between pitch types, independent of competition level.  相似文献   

Classroom Discussions with Student‐Led Feedback: a Useful Activity to Enhance Development of Critical Thinking Skills     

Kirby D. Hayes  Amy A. Devitt 《Journal of Food Science Education》2008,7(4):65-68

ABSTRACT: Critical thinking skills (CTS) are the core learning outcome measures for higher education. Generally, CTS are not extensively developed or practiced during primary and secondary education. As such, early cultivation of CTS is essential for mastery prior to collegiate matriculation. Weekly engagement in 50 min of classroom discussion with student feedback (CDSF) was utilized to develop the CTS of students in an introductory food science course at Purdue Univ. Students' critical thinking ability was assessed longitudinally over a 16‐wk semester using the ACT‐CAAP? (Collegiate Assessment of Academic Proficiency) critical thinking test. The ACT‐CAAP measures the students' ability to analyze, evaluate, and extend an argument described in a short passage. We hypothesized that the implementation of CDSF for 16 wk would expedite development of CTS for students enrolled in the course. The CDSF intervention significantly increased critical thinking ability for non‐native English speaking students as compared to native English speaking students. Students who were classified as sophomore status or above when compared to freshmen and students enrolled as food science majors when compared to other majors also demonstrated increased critical thinking ability. Recitation size also significantly influenced critical thinking ability where students enrolled in a relatively small recitation section had elevated critical thinking when compared to the abilities of those students enrolled in a large recitation. These observations suggest that engaging students in classroom discussions with student‐led feedback is a useful instructional technique for developing CTS. Further, the data suggest the development of critical thinking skill among food science majors can be augmented when classroom discussions with student‐led feedback are conducted in smaller sized recitations.  相似文献   

Apes track false beliefs but might not understand them     

Kristin Andrews 《Learning & behavior》2018,46(1):3-4

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Detroit Abandons Plan for All‐Male Schools,Citing Bias     

Arthur S. Hayes  Jonathan M. Moses 《Equity & Excellence in Education》2013,46(2-4)

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Classroom Heritage     

Miriam Wise Andrews 《The Educational forum》2013,77(1)

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Ten Years of Strategies   总被引：1，自引：1，他引：0  

Richard Andrews 《Changing English: An International Journal of English Teaching》2008,15(1):77-85

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The heat capacities of organic compounds at low temperatures. II. A low temperature thermostat. Thousandth degree copper-constantan thermocouple reference tables from 85° to 310° K     

John Campbell Southard  Donald Hatch Andrews 《Journal of The Franklin Institute》1929,207(3):323-339

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Quantification of maximal power output in well-trained cyclists     

Thomas A. Wackwitz  Clare L. Minahan  Trish King  Chantelle Du Plessis  Mark H. Andrews  Phillip M. Bellinger 《Journal of sports sciences》2021,39(1):84-90

ABSTRACT

This study aimed to compare mechanical variables derived from torque-cadence and power-cadence profiles established from different cycle ergometer modes (isoinertial and isokinetic) and modelling procedures (second- and third-order polynomials), whilst employing a novel method to validate the theoretical maximal power output (P_max). Nineteen well-trained cyclists (n = 12 males) completed two experimental sessions comprising six, 6-s maximal isoinertial or isokinetic cycling sprints. Maximal pedal strokes were extracted to construct power–cadence relationships using second- and third-order polynomials. A 6-s sprint at the optimal cadence (F_opt) or optimal resistance (T_opt) was performed to assess construct validity of P_max. No differences were found in the mechanical parameters when derived from isokinetic (P_max = 1311 ± 415, F_opt = 118 ± 12) or isoinertial modes (P_max = 1320 ± 421, F_opt = 116 ± 19). However, R² improved (P < 0.02) when derived from isoinertial sprints. Third-order polynomial modelling improved goodness of fit values (Standard Error, adjusted R²), but derived similar mechanical parameters. Finally, peak power output during the optimised sprint did not significantly differ from the theoretical P_max in both cycling modes, thus providing construct validity. The most accurate P-C profile can be derived from isoinertial cycling sprints, modelled using third-order polynomial equations.  相似文献   

Overcoming Obstacles: Approaches to Dealing with Problem Pupils     

Hayley Martin  & Sid Hayes 《British Journal of Special Education》1998,25(3):135-139

Hayley Martin, Teacher of Physical Education at Beacon Community College, Crowborough, and Sid Hayes, Senior Lecturer in Physical Education, Faculty of Education, Sports and Leisure, University of Brighton, consider the effects of feedback to pupils, and identify successful strategies for dealing with problem behaviour.  相似文献   

Developmental continuity in theory of mind: speed and accuracy of belief-desire reasoning in children and adults     

Apperly IA  Warren F  Andrews BJ  Grant J  Todd S 《Child development》2011,82(5):1691-1703

On belief-desire reasoning tasks, children first pass tasks involving true belief before those involving false belief, and tasks involving positive desire before those involving negative desire. The current study examined belief-desire reasoning in participants old enough to pass all such tasks. Eighty-three 6- to 11-year-olds and 20 adult participants completed simple, computer-based tests of belief-desire reasoning, which recorded response times as well as error rates. Both measures suggested that, like young children, older children and adults find it more difficult to reason about false belief and negative desires than true beliefs and positive desires. It is argued that this developmental continuity is most consistent with either executive competence or executive performance accounts of the development of belief-desire reasoning.  相似文献