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.     

Validity of Holland’s theory in adolescence: evidence from a Slovak sample

The underlying calculus assumption of Holland’s theory was tested in two samples of primary school students (N₁ = 400 and N₂ = 250) with an average age of 13.86 and 14.14 years, respectively. Both exploratory and confirmatory multidimensional scaling and Hubert and Arabie’s randomization test of hypothesized order relations were calculated. The circular spatial arrangement of RIASEC types was not confirmed in either of the two samples. The study discusses possible causes of the inappropriateness of using Holland’s model in an adolescent sample.

     

Violent Political Contexts and the Emotional Concerns of Township Youth

This article presents the findings of a series of studies that examine the perceptions of black South African youth about township life and the civil conflict and violence it encompasses. The studies were conducted with comparable samples of 58–82 youth at 3 points in South Africa's history, all characterized by high levels of violence but differing in terms of their political contexts. These contexts were overt State-community conflict, covert opposition and political repression, and intracommunity violence. The data revealed that in all 3 contexts youth reported a high exposure to violence, but only when violence occurred in the context of intracommunity conflict was it subjectively construed to be the most problematic. Reasons for this may include the real increase in more extreme forms of violence, including deaths, that occurs in intracommunity violence and the blurring of the distinction between political and criminal violence in this context.     

To give or not to give: children's and adolescents' sharing and moral negotiations in economic decision situations

This study interconnects developmental psychology of fair and moral behavior with economic game theory. One hundred eighty-nine 9- to 17-year-old students shared a sum of money as individuals and groups with another anonymous group (dictator game). Individual allocations did not differ by age but did by gender and were predicted by participants' preferences for fair allocations. Group decision making followed a majority process. Level of moral reasoning did not predict individual offers, but group members with a higher moral reasoning ability were more influential during group negotiations and in influencing group outcomes. The youngest participants justified offers more frequently by referring to simple distribution principles. Older participants employed more complex reasons to justify deviations from allocation principles.     

Apprenticeship in England – the continued role of the academic–vocational divide in shaping learner identities

Successive governments have pledged to enhance the quality of apprenticeship in Britain so as to achieve ‘parity of esteem’ with academic study. Yet, at the same time, the discourse of the academic-vocational divide has dominated the academic, policy-maker and practitioner debates. This paper draws on two recent studies designed to explore the learner identities of apprentices on different apprenticeship programmes: motor vehicle maintenance (level 2) and engineering (level 3). Through this work, we are able to explore the role of the academic–vocational divide in identity construction and to challenge assumptions about vocational learners. It will be argued, that, far from being ‘naturally practical’, the young people draw on normative discursive categories in their construction of continuous identities. The findings raise important questions about the UK apprenticeship system as currently conceived, while at the same time drawing attention to the possibility for change.     

Contemporary Art and the Role of Interpretation: Reflections from Tate Modern's Summer Institute for Teachers

Recent research indicates that the taught curriculum in art and design secondary school education pays scant attention to meaning‐making in visual art. This article explores possibilities for teaching interpretation through a report on an action‐research project based on Tate Modern's Summer Institute for Teachers. In doing so it argues for the value and necessity of interpretation as a taught skill.     

Social‐emotional well‐being and resilience of children in early childhood settings – PERIK: an empirically based observation scale for practitioners

Compared with the traditional focus on developmental problems, research on positive development is relatively new. Empirical research in children's well‐being has been scarce. The aim of this study was to develop a theoretically and empirically based instrument for practitioners to observe and assess preschool children's well‐being in early childhood settings. The analysis of preschool teachers' ratings yields six dimensions of social‐emotional well‐being: (1) making contact/social performance, (2) self control/thoughtfulness, (3) self‐assertiveness, (4) emotional stability/coping with stress, (5) task orientation, (6) pleasure in exploration. Composite scales were constructed. PERIK consists of six scales of six items each. The scales differentiate in both the upper and lower range and despite their brevity have good psychometric qualities. The instrument was published together with a booklet containing examples of how PERIK observations can be employed in practical work with children.