The effects of mid-flight whole-body and trunk rotation on landing mechanics: implications for anterior cruciate ligament injuries

ABSTRACT

The purpose was to quantify the effects of mid-flight whole-body and trunk rotation on knee mechanics in a double-leg landing. Eighteen male and 20 female participants completed a jump-landing-jump task in five conditions: no rotation, testing leg ipsilateral or contralateral (WBRC) to the whole-body rotation direction, and testing leg ipsilateral (TRI) or contralateral to the trunk rotation direction. The WBRC and TRI conditions demonstrated decreased knee flexion and increased knee abduction angles at initial contact (2.6 > Cohen’s dz > 0.3) and increased peak vertical ground reaction forces and knee adduction moments during the 100 ms after landing (1.7 > Cohen’s dz > 0.3). The TRI condition also showed the greatest knee internal rotation angles at initial contact and peak knee abduction and internal rotation angles and peak knee extension moments during the 100 ms after landing (2.0 > Cohen’s dz > 0.5). Whole-body rotation increased contralateral knee loading because of its primary role in decelerating medial-lateral velocities. Trunk rotation resulted in the greatest knee loading for the ipsilateral knee due to weight shifting and mechanical coupling between the trunk and lower extremities. These findings may help understand altered trunk motion in anterior cruciate ligament injuries.     

The Evaluation of Training for Health-Care Professionals and Community Leaders Regarding 6-Month Exclusive Breastfeeding in Northeast Thailand

To address the reduction of the 6-month exclusive breastfeeding (EBF) rate in Northeast Thailand, a 3-year 6-month EBF intervention model was developed using concept mapping. A training for health-care professionals and community leaders was prioritized as the initial intervention. The aim was to assess the feasibility of the training intervention and its potential to improve 6-month EBF knowledge. A pre- and posttest, and an open question were conducted. Data were analyzed using t tests and thematic analysis. For the 17 health-care professionals and community leaders who participated, the mean 6-month EBF knowledge scores improved significantly from 5.28 to 10.21 (p value < .01). It is recommended that this workshop could be duplicated and scaled up in other regions across Thailand to standardize care.     

Unemployment and social class stigmas

Western economies have seen a shift away from a model of job security to a model of work precarity. Cycles of unemployment are a defining feature of the new precarious economy. Given these cycles of unemployment, it becomes imperative to explore the barriers to reemployment. The present study uses stigma communication to explore the intersection of two barriers to reemployment: the stigmatization of unemployment and social class position. Analysis of 40 interviews revealed that the meaning of unemployment changed depending on the perceived social class of an unemployed person. Participants described typical unemployed people as pathologically lazy and unmotivated. Upper class unemployed people were stigmatized as a product of privilege. Middle class unemployed people were relatively unstigmatized. The typical unemployed person merged with the typical unemployed lower class person, suggesting that the dominant meaning of unemployment assumes that unemployment is a lower class phenomenon that is preventable if the lower class person would work harder.     

Prosodic correlates of stress in babbling: an acoustical study

Prelinguistic babbling often seems remarkably speech-like, not because it has recognizable words but because it seems to have adult-like prosody. To quantify this impression, we compared disyllabic sequences from five infants and five adults in terms of the use of frequency, intensity, and duration to mark stress. Significantly larger values for the three acoustic variables were observed on stressed than on unstressed syllables independent of syllable position for both groups. Adults showed the correlates of utterance final syllables--lower f0, lower intensity, and longer duration; infants showed only decrease in intensity. Ratios for stressed to unstressed syllables and participation of the three variables in stress production in individual disyllables were highly similar in both groups. No bias toward the English lexical trochaic stress pattern was observed. We conclude that infants in English environments produce adult-like stress patterns before they produce lexical items, which specify stress. Acoustic and perceptual analyses are used to explore stress marking by prelinguistic infants in an English language environment. Results show that infants employ the three acoustic correlates of stress in individual syllables in a manner largely similar to that of adult speakers, although they do not show second-syllable declination effects or an English language trochaic stress bias.     

Partnering with Districts to Expand an After-School Maths Club Programme

Abstract

A key intervention of the South African Numeracy Chair Project (SANCP) since 2011 has been the introduction of mathematics (or maths) clubs, which occur in the out-of-school time space. In 2016 the maths club concept was developed into a 15-week Pushing for Progression (PfP) teacher development programme which supports primary school mathematics teachers to run clubs beyond the SANCP local area. Expanding intervention models beyond local schools is imperative in the second phase of the SANCP (2016–2020). Working from a mixed methods methodological approach, the researchers collected pre- and post-data for a 4-operations assessment of the entire PfP programme. In this article they share learner data from one of the nine teachers who participated in the PfP maths club programme in the Uitenhague District, Eastern Cape, South Africa, to illuminate how partnerships between academics, district officials and teachers can enable powerful student learning in the club space. They argue further that within the tightly focused development programme run by teachers in this one district, it is possible for learners to make substantive progress in mathematical proficiency (MP) (especially procedural fluency and conceptual understanding) when comparing scores and learner methods between a pre- and post- assessment.     

Effects of organizational pictures and modality as a feedback strategy on learner comprehension and satisfaction

One of the strongest instructional interventions documented in educational literature is the use of feedback to influence learning outcomes. However, there is lack of empirical research specifically pertaining to the use of multimedia in the feedback message. The purpose of this research was to test whether organizational pictures and modality as a feedback strategy had an effect on learner comprehension and satisfaction. The research design was a 2 Multimedia (Picture Present vs. Picture Absent) × 2 Modality (Narration vs. On-screen Text) × Trial (Trial 1 vs. Trial 2) with Multimedia and Modality serving as between-subject conditions and Trial serving as a repeated measure. One-hundred fifteen university students participated in the study. Findings show statistically significant increases in comprehension scores from Trial 1 to Trial 2 assessments for all four treatment conditions. Learners in the Picture present conditions were statistically more satisfied with the learning experience. Additionally, we used eye-tracking to verify the extent to which the pictures were used in the feedback message. A discussion and recommendations for future research and feedback design are provided.     

Using conjoint analysis to examine bias in referral to a behavior intervention program

Research in the United States suggests that teachers view Black students' misbehavior as more likely to reoccur, but such research has not disentangled the effect of race from related factors. We used conjoint analysis to experimentally test the effect of multiple student characteristics on the chances of being referred for a behavior intervention program. Although preservice teacher participants were not more likely to refer Black students, they were more likely to refer students who had lower grades, lived in poverty, lived with a single mother, and had been retained. We interpret these results and highlight directions for future research and practice.     

Weak Ties in Networked Communities

Communities with high levels of social capital are likely to have a higher quality of life than communities with low social capital. This is due to the greater ability of such communities to organize and mobilize effectively for collective action because they have high levels of social trust, dense social networks, and well-established norms of mutuality (the major features of social capital). Communities with “bridging” social capital (weak ties across groups) as well as “bonding” social capital (strong ties within groups) are the most effective in organizing for collective action. People who belong to multiple groups act as bridging ties. When people with bridging ties use communication media, such as the Internet, they enhance their capability to educate community members and to organize, as needed, for collective action. This article summarizes evidence from stratified household survey data in Blacksburg, VA, showing that people with weak (bridging) ties across groups have higher levels of community involvement, civic interest, and collective efficacy than people without bridging ties among groups. Moreover, heavy Internet users with bridging ties have higher social engagement, use the Internet for social purposes, and have been attending more local meetings and events since going online than heavy Internet users with no bridging ties. These findings may suggest that the Internet—in the hands of bridging individuals-is a tool for enhancing social relations and information exchange, and for increasing face-to-face interaction, all of which help to build both bonding and bridging social capital in communities.