Longer-term effects of minimalist shoes on running performance,strength and bone density: A 20-week follow-up study*

This study investigated whether male runners improve running performance, running economy, ankle plantar flexor strength, and alter running biomechanics and lower limb bone mineral density when gradually transitioning to using minimalist shoes for 100% of weekly running. The study was a planned follow-up of runners (n?=?50) who transitioned to minimalist or conventional shoes for 35% of weekly structured training in a previous 6-week randomised controlled trial. In that trial, running performance and economy improved more with minimalist shoes than conventional shoes. Runners in each group were instructed to continue running in their allocated shoe during their own preferred training programme for a further 20 weeks while increasing allocated shoe use to 100% of weekly training. At the 20-week follow-up, minimalist shoes did not affect performance (effect size: 0.19; p?=?0.218), running economy (effect size: ≤?0.24; p?≥?0.388), stride rate or length (effect size: ≤?0.12; p?≥?0.550), foot strike (effect size: ≤?0.25; p?≥?0.366), or bone mineral density (effect size: ≤?0.40; p?≥?0.319). Minimalist shoes increased plantar flexor strength more than conventional shoes when runners trained with greater mean weekly training distances (shoe*distance interaction: p?=?0.036). After greater improvements with minimalist shoes during the initial six weeks of a structured training programme, increasing minimalist shoe use from 35% to 100% over 20 weeks, when runners use their own preferred training programme, did not further improve performance, running economy or alter running biomechanics and lower limb bone mineral density. Minimalist shoes improved plantar flexor strength more than conventional shoes in runners with greater weekly training distances.     

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.     

Examining the effects of a highly rated science curriculum unit on diverse students: Results from a planning grant

This article reports on the results of a planning grant studying the effects of a highly rated curriculum unit on a diverse student population. The treatment was introduced to 1500 eighth grade students in five middle schools selected for their ethnic, linguistic, and socioeconomic diversity. Students were given pre‐, post‐, and delayed posttests on a Conservation of Matter Assessment and measures of motivation and engagement. This quasi‐experiment found statistically significant posttest results for achievement, basic learning engagement, and goal orientation. Analyses of disaggregated data showed that subgroups of students in the treatment condition outscored their comparison group peers (n = 1500) in achievement in all cases, except for students currently enrolled in ESOL. Analysis of video data of a diverse group of four students as the unit was enacted suggests that students entered a learning environment that permitted them to function in different, but consistent ways over time; that is, the frequency of students' manipulation of objects showed a different pattern of engagement for each of the four students compared with patterns of verbal responses such as the use of scientific terms. The results of this planning grant paved the way for a large study of the scale‐up of highly rated curriculum units. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 912–946, 2005     

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.     

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.