Understanding the track and field sprint start through a functional analysis of the external force features which contribute to higher levels of block phase performance

This study aimed to identify the continuous ground reaction force (GRF) features which contribute to higher levels of block phase performance. Twenty-three sprint-trained athletes completed starts from their preferred settings during which GRFs were recorded separately under each block. Continuous features of the magnitude and direction of the resultant GRF signals which explained 90% of the variation between the sprinters were identified. Each sprinter’s coefficient score for these continuous features was then input to a linear regression model to predict block phase performance (normalised external power). Four significant (p < 0.05) predictor features associated with GRF magnitude were identified; there were none associated with GRF direction. A feature associated with greater rear block GRF magnitudes from the onset of the push was the most important predictor (β = 1.185), followed by greater front block GRF magnitudes for the final three-quarters of the push (β = 0.791). Features which included a later rear block exit (β = 0.254) and greater front leg GRF magnitudes during the mid-push phase (β = 0.224) were also significant predictors. Sprint practitioners are encouraged, where possible, to consider the continuous magnitude of the GRFs produced throughout the block phase in addition to selected discrete values.     

Stressors in elite sport: a coach perspective

We examined the varying performance and organizational stressors experienced by coaches who operate with elite athletes. Following interviews with eleven coaches, content analysis of the data revealed coaches to experience comparable numbers of performance and organizational stressors. Performance stressors were divided between their own performance and that of their athletes, while organizational stressors included environmental, leadership, personal, and team factors. The findings provide evidence that coaches experience a variety of stressors that adds weight to the argument that they should be labelled as "performers" in their own right. A variety of future research topics and applied issues are also discussed.     

The self-concept level of black adolescents with and without African names

The self-concept level of Black adolescents with African names was explored. Black males with and without African names were first identified. All participants and their parents were then administered the Terrell and Taylor Black Ideology Scale and the Coopersmith Self-Esteem Inventory. Differences between groups on the self-concept measures were then examined using a one way MANOVA with parents' scores on the self-concept measures serving as covariates. Significant differences were found between groups. Supplemental analyses revealed no differences between groups on the Coopersmith. However, adolescents with African names had significantly higher scores on the Black self-concept scales than did those without African names.     

Effects of race of examiner and type of reinforcement on the intelligence test performance of lower-class black children

This study examined the effects of race of examiner and type of reinforcement upon the WISC-R performance of lower-class black children. A total of 120 black males were selected and assigned to either a white or black examiner to form two groups. Within each group, children were given no reinforcement, tangible reinforcement, traditional social reinforcement, or culturally relevant social reinforcement after each correct response. Children given tangible rewards, regardless of race of examiner, obtained significantly higher scores than did children given no reinforcement or children given traditional social reinforcement. Also, children given culturally relevant social reinforcement by a black examiner obtained significantly higher scores than did children given culturally relevant reinforcement by the white examiner.     

‘Teaching’ the path towards university: understanding student access through storied-futures and meritocratic grand narratives

The notion that the stories of our lives shape dispositions towards imagined futures is another lens through which university underrepresentation should be viewed. A storied lens attends to how futures, like university attendance, are storied during childhood to the extent that some youth imagine, and therefore plan, these futures as natural progression. Such was the case for study participants, indicating that childhood stories contain answers for mitigating social reproduction connected to parental education and cultural forces within the home. Examining social mobility through the underexplored storied-futures grand narrative presents unique solutions that lay hidden within the dominant meritocratic grand narrative.     

Lower limb joint kinetics during the first stance phase in athletics sprinting: three elite athlete case studies

Abstract

This study analysed the first stance phase joint kinetics of three elite sprinters to improve the understanding of technique and investigate how individual differences in technique could influence the resulting levels of performance. Force (1000 Hz) and video (200 Hz) data were collected and resultant moments, power and work at the stance leg metatarsal-phalangeal (MTP), ankle, knee and hip joints were calculated. The MTP and ankle joints both exhibited resultant plantarflexor moments throughout stance. Whilst the ankle joint generated up to four times more energy than it absorbed, the MTP joint was primarily an energy absorber. Knee extensor resultant moments and power were produced throughout the majority of stance, and the best-performing sprinter generated double and four times the amount of knee joint energy compared to the other two sprinters. The hip joint extended throughout stance. Positive hip extensor energy was generated during early stance before energy was absorbed at the hip as the resultant moment became flexor-dominant towards toe-off. The generation of energy at the ankle appears to be of greater importance than in later phases of a sprint, whilst knee joint energy generation may be vital for early acceleration and is potentially facilitated by favourable kinematics at touchdown.     

Contextual effects on predicting risk for reading difficulties in first and second grade

This study utilized early reading assessment data from a randomized trial of 210 urban and rural schools in Texas to examine contextual effects on risk prediction in first and second grade. The primary objective was to examine the roles of (a) individual differences, (b) the grade 1 classroom, and (c) the pairing of first and second grade teachers in determining grade 2 outcomes in word reading and fluency. A second objective was to investigate whether the administration format of the assessment (paper, paper plus desktop, handheld plus desktop) or the level of teacher support (web mentoring, no mentoring) moderated the prediction. These moderator variables proved not to be significant. Subsequent analyses found that a combination of student pretest and mean of pretest classroom was a better predictor than student pretest alone. Additionally, the effect of student scores varied by teacher-pair. On average, intraclass correlations (ICCs) ranged from 6% to 17%. Differences in ICCs at the classroom level were much greater than at the school level, and differences in urban schools were twice that of rural schools.