Acute effects of static stretching on characteristics of the isokinetic angle - torque relationship, surface electromyography, and mechanomyography

The aims of this study were to examine the acute effects of static stretching on peak torque, work, the joint angle at peak torque, acceleration time, isokinetic range of motion, mechanomyographic amplitude, and electromyographic amplitude of the rectus femoris during maximal concentric isokinetic leg extensions at 1.04 and 5.23 rad x s(-1) in men and women. Ten women (mean +/- s: age 23.0 +/- 2.9 years, stature 1.61 +/- 0.12 m, mass 63.3 +/- 9.9 kg) and eight men (age 21.4 +/- 3.0 years, stature 1.83 +/- 0.11 m, mass 83.1 +/- 15.2 kg) performed maximal voluntary concentric isokinetic leg extensions at 1.04 and 5.23 rad x s(-1). Following the initial isokinetic tests, the dominant leg extensors were stretched using four static stretching exercises. After the stretching, the isokinetic tests were repeated. Peak torque, acceleration time, and electromyographic amplitude decreased (P< or = 0.05) from pre- to post-stretching at 1.04 and 5.23 rad . s(-1); there were no changes (P > 0.05) in work, joint angle at peak torque, isokinetic range of motion, or mechanomyographic amplitude. These findings indicate no stretching-related changes in the area under the angle - torque curve (work), but a significant decrease in peak torque, which suggests that static stretching may cause a "flattening" of the angle - torque curve that reduces peak strength but allows for greater force production at other joint angles. These findings, in conjunction with the increased limb acceleration rates (decreased acceleration time) observed in the present study, provide tentative support for the hypothesis that static stretching alters the angle - torque relationship and/or sarcomere shortening velocity.     

Can High School Achievement Tests Serve to Select College Students?

Postsecondary schools have traditionally relied on admissions tests such as the SAT and ACT to select students. With high school achievement assessments in place in many states, it is important to ascertain whether scores from those exams can either supplement or supplant conventional admissions tests. In this study we examined whether the Arizona Instrument to Measure Standards (AIMS) high school tests could serve as a useful predictor of college performance. Stepwise regression analyses with a predetermined order of variable entry revealed that AIMS generally did not account for additional performance variation when added to high school grade-point average (HSGPA) and SAT. However, in a cohort of students that took the test for graduation purposes, AIMS did account for about the same proportion of variance as SAT when added to a model that included HSGPA. The predictive value of both SAT and AIMS was generally the same for Caucasian, Hispanic, and Asian American students. The ramifications of universities using high school achievement exams as predictors of college success, in addition to or in lieu of traditional measures, are discussed.     

Lane bias in elite-level swimming competition

Performance outcomes at the 2013 World Swimming Championship were previously shown to be biased depending on the swimmer’s lane assignment. The purpose of this study was to determine if this kind of bias was unique, and if not, if the bias was related to the temporary or permanent nature of the pool. The effect of lane on the average odd-length split minus the preceding even-length split in the 800- and 1500-m freestyle events, and on the relative change from qualifying to preliminary performance in the 50-m events, was determined for 16 other elite-level competitions. Depending on the swimmers’ direction, split times were on average 0.16 s slower or faster in at least one lane at each of the 16 competitions, and in 49% of all lanes analysed. In 5 competitions, swimmers were shown to be faster in a majority of lanes in one direction as compared to the other. Analysis of the 50-m events at these 5 competitions indicate that preliminary performances were between 0.5 and 0.9% slower or faster than qualifying times, which is consistent with the direction effect observed in the distance freestyle events. Further, lane biases occur more often in temporary pools (70% of lanes) than in permanent pools (35% of lanes), with water currents as the most plausible cause. The prevalence of lane bias at elite-level swimming competition highlights the need for the implementation of policies and procedures to prevent such bias from occurring again in the future.     

弹性领导及风险根源

当前许多学校由于注重标准和绩效责任,对青年人滥用药物、行为不良、不安全性行为、暴力和学业失败采用有很大风险的阻止方式。但这是正确的方式吗?学校和学生能否从专注于促进教育成就和社会道德发展的技能中获益?10多年的研究表明学生的成功与这些计划毫无关系,我们需要另一种解决问题的方式——弹性领导。     

A 30 Year Perspective On Best Practices for Consultation Training

This article uses the author's 30 years of teaching consultation as a basis for developing suggestions for those providing training in this field. The article addresses questions about what the content of training should be, how consultation training can link theory to practice and how to respond to persistent challenges to training (e.g., freedom versus constraint, multicultural consultation, and when consultation training should be offered within a preservice curriculum for developing school-based consultants). The training suggestions derive from a model of consultation and consultation training that is based in constructivism and seeks to enhance feelings of empowerment and long term implementation of consultation on the part of the trainee. The article proposes a practitioner-researcher model in which practicing consultants view themselves as researchers who collect data and share information about their practice with other school-based consultants. These shared practices are used to inform the knowledge base and are used as a basis for contributing to the scholarly literature. Finally, this article proposes directions for researching the process and outcome of consultation training that cut across all of the issues raised in this article.     

The effects of faking on non-cognitive predictors of academic performance in University students

This study examined the extent to which students could fake responses on personality and approaches to studying questionnaires, and the effects of such responding on the validity of non-cognitive measures for predicting academic performance (AP). University students produced a profile of an ‘ideal’ student using the Big-Five personality taxonomy, which yielded a stereotype with low scores for Neuroticism, and high scores for the other four traits. A sub-set of participants were allocated to a condition in which they were instructed to fake their responses as University applicants, portraying themselves as positively as possible. Scores for these participants revealed higher scores than those in a control condition on measures of deep and strategic approaches to studying, but lower scores on the surface approach variable. Conscientiousness was a significant predictor of AP in both groups, but the predictive effect of approaches to studying variables and Openness to Experience identified in the control group was lower in the group who faked their responses. Non-cognitive psychometric measures can be valid predictors of AP, but scores on these measures can be affected by instructional set. Further implications for psychometric measurement in educational settings are discussed.     

Trajectories of perinatal depressive symptoms in the context of the COVID-19 pandemic

This study sought to advance understanding of the potential long-term consequences of the COVID-19 pandemic for child development by characterizing trajectories of maternal perinatal depression, a common and significant risk factor for adverse child outcomes. Data came from 393 women (86% White, 8% Latina; mean age = 33.51 years) recruited during pregnancy (n = 247; mean gestational age = 22.94 weeks) or during the first year postpartum (n = 146; mean child age = 4.50 months; 55% female). Rates of depression appear elevated, relative to published reports and to a pre-pandemic comparison group (N = 155). This study also provides evidence for subgroups of individuals who differ in their depressive symptom trajectories over the perinatal period. Subgroup membership was related to differences in maternal social support, but not to child birth outcomes.