Two types of ball-effector interaction and their relative contribution to soccer kicking

The study attempts a closer examination of the ball-foot interaction at the instant of soccer kicking using high speed videotaping. This allows a detailed biomechanical analysis of the collision. A central question is whether the ball-foot interaction can be modeled as an elastic impact, or as a mixture of ‘impact-like’ and ‘throwing-like’ patterns. The findings prove that the theory of conservation of momentum alone is not adequate for modeling kicking: additional momentum and mechanical energy is supplied to the system during the collision phase because of the muscle work. This is due to the relatively long duration of collision (about 16 ms) and the large ball-foot displacement (about 26.0 cm). More than 50% of the ball's speed and at least 30% of its kinetic energy is imparted to the ball without any contribution of the potential energy of the ball deformation.     

Self-Compassion and Need Frustration Moderate the Effects of Upward Appearance Comparisons on Body Image Discrepancies

Abstract

Drawing from diverse theoretical frameworks, we examined predictors of discrepancy between current and ideal body image in a sample of 396 Greek adolescents. The participants completed assessments of the frequency of comparing oneself with someone of perceived better appearance, appearance evaluations, frustration of basic psychological needs, and appearance self-compassion. We found that upward appearance comparisons negatively predicted appearance evaluation, which in turn was a negative predictor of body image discrepancy. Moderated mediation analyses showed that appearance self-compassion buffered, whereas psychological need frustration augmented the negative effects of upward comparisons on appearance evaluation. Our findings contribute to the growing literature on body image discrepancies in adolescence by examining moderating factors that amplify or buffer such discrepancies, hence identifying viable intervention pathways.     

Comparison of sport achievement orientation of male wheelchair basketball athletes with congenital and acquired disabilities

The study was designed to examine the sport achievement orientations of male wheelchair basketball athletes who differed by onset of experienced disability (congenital and acquired). The full Sport Orientation Questionnaire was administered to 166 U.S. national athletes. Athletes with congenital disabilities had higher mean scores than their peers with acquired disabilities on the three subscales of the full form and on the extraction items as a short form (Competitiveness, Win Orientation, and Goal Orientation). Multivariate analysis of variance yielded no significant differences between groups. Significant differences on Competitiveness and Goal Orientation, with a higher mean were found for the group with congenital disabilities than for the group with acquired disabilities. The results are discussed in relation to the literature, nature of wheelchair basketball, and application of the test to such athletes.     

Unhealthy weight control behaviours in adolescent girls: a process model based on self-determination theory

This study used self-determination theory (Deci, E.L., & Ryan, R.M. (2000). The ‘what’ and ‘why’ of goal pursuits: Human needs and the self-determination of behavior. Psychological Inquiry, 11, 227–268.) to examine predictors of body image concerns and unhealthy weight control behaviours in a sample of 350 Greek adolescent girls. A process model was tested which proposed that perceptions of parental autonomy support and two life goals (health and image) would predict adolescents’ degree of satisfaction of their basic psychological needs. In turn, psychological need satisfaction was hypothesised to negatively predict body image concerns (i.e. drive for thinness and body dissatisfaction) and, indirectly, unhealthy weight control behaviours. The predictions of the model were largely supported indicating that parental autonomy support and adaptive life goals can indirectly impact upon the extent to which female adolescents engage in unhealthy weight control behaviours via facilitating the latter's psychological need satisfaction.     

Exercise imagery and its correlates in older adults

Objectives

The purpose of the present study was to test a structural model examining the interrelationships between exercise imagery, self-reported exercise behaviour and well-being in older adults.

Design

Cross-sectional survey.

Method

Participants were 499 older Greek adults (50.10% males) aged between 51 and 84 years (M age = 57.31; SD = 5.52) who completed questionnaires measuring exercise imagery use, exercise behaviour, subjective vitality, and physical self-worth. The relationship between these variables was tested with a structural model based on the applied model of imagery use for exercise (Munroe-Chandler & Gammage, 2005).

Results

Energy imagery positively predicted exercise behaviour and subjective vitality, and appearance and technique imagery positively predicted physical self-worth.

Conclusions

These results indicate older adults engage in different types of imagery to motivate themselves to exercise and improve their well-being, thus implying that the content of imagery interventions should be specifically tailored to the outcomes older adults wish to realise for interventions to be effective.     

Criteria of personal, boys', and girls' popularity as ranked by Greek adolescents

This study examined what Greek adolescents believe are the most important criteria of personal, boys', and girls' popularity in their age group. Participants were 364 students aged between 12 and 15 years. Seven main criteria of popularity were identified: sport competence, physical appearance, academic ability, being a good friend, being sociable, having a good sense of humor, and having the 'right circle of friends'. With regard to personal popularity, being a good friend and being sociable were the two most highly ranked criteria for both boys and girls across all ages. Boys and girls perceived differently the most important criteria of boys' and girls' popularity. Specifically, for same-sex popularity, being a good friend was the most highly ranked criterion, whereas for other-sex popularity, physical attractiveness was the most highly ranked criterion. The findings imply that friendship and social affiliation are the most important criteria of popularity in Greek adolescents.     

Development of the Greek version of the Spiritual Intelligence Self-Report Inventory-24 (KAPN): factor structure and validation

ABSTRACT

The Spiritual Intelligence Self-Report Inventory 24 (SISRI-24) is widely used to assess spiritual intelligence (SI) in general population samples. The current study explored the Greek version SISRI-24 factor structure in a convenience sample of 1777 adults. A translation of the original scale was performed in different stages, so as to obtain a fully comprehensible and accurate equivalent. Psychometric properties were analyzed at the level of item. The four-factor solution proposed in the original SISRI-24 was not confirmed. Instead, an alternative model, in which the SISRI-24 structure was revised and trimmed to a final three-factor, 17-item short-form version (KAPN), produced an instrument of sound construct validity [fit indices: CFI?=?.92, TLI?=?.91, RMSEA?=?.06, SRMR?=?.06] and robust internal consistency. The results are sufficient for endorsing the suitability of KAPN in Greek speaking populations, and extend cross-cultural support for the SI model. Implications and recommendations for future directions of research are discussed.