Isokinetic ankle eversion and inversion strength profiling of female ballet dancers

ABSTRACT

Ankle injuries are highly prevalent in ballet, with strength highlighted as a primary risk factor. To profile ankle strength, fourteen female ballet dancers (age: 19.29 ± 1.59 years) completed an isokinetic testing protocol comprising concentric eversion (CON_EV) and inversion (CON_INV), and, eccentric inversion (ECC_INV) trials at four angular velocities (30° · s^?1, 60° · s^?1, 90° · s^?1, 120° · s^?1) for both the dominant and non-dominant limb. In addition to Peak Torque (PT) and the corresponding Dynamic Control Ratios (DCRs), angle-specific derivatives of strength (AST) and Functional Range (FR) were calculated. There was no evidence of any significant bilateral strength asymmetry (p = 0.90) across all metrics, and no significant interactions with limb and contraction mode or velocity. A significant main effect for contraction mode (p = 0.001) highlighted greater ECC_INV strength – which was maintained with increasing isokinetic velocity – in contrast to reductions in CON_EV and CON_INV strength. Specifically, dancers are ECC_INV dominant at angular velocities greater than 60° · s^?1, which is likely to be characteristic of most functional tasks. The lack of bilateral asymmetry may be attributed to dance training interventions that facilitate bilateral development, but ipsilateral mode and velocity-specific asymmetries have implications for injury risk and the training needs of female ballet dancers.     

Mechanical behaviour of natural turf sports pitches across a season

A study assessing the mechanical behaviour of six natural turf pitches of varying sporting level and surface construction was undertaken over a period of 10?months, spanning a sporting season (August 2010 to May 2011). Penetration resistance and shear resistance were measured with the GoingStick^?, impact hardness and surface energy absorption were measured with the 2.25?kg Clegg Impact Soil Tester and the Dynamic Surface Tester device, respectively. The two sand rootzone pitches were more resistant to deformation and less variable in their impact behaviour (impact hardness and energy absorption) through the season than the native soil pitches containing greater proportions of silt and clay. Greater consistency was shown for penetration resistance and shear resistance on one of the sand rootzone pitches, with the other behaving similar to the native soil pitches for these parameters. The sand rootzone surfaces exhibited greater (P?<?0.05) impact hardness than the native soil pitches in the winter period of the season (November to mid-March) compared to the beginning or end periods of the season, where data were statistically similar (P?>?0.05). The greater consistency of sand rootzone surfaces should be considered for the effect it may have on player and team performance, and injury potential. Analysis of data against Performance Quality Standard benchmarks indicated that all data on the sand rootzones exceeded preferred values for impact hardness, indicating these ranges may be obsolete for the modern elite natural turf surface.     

The influence of equipment variations on sliotar–hurley impact in the Irish game of hurling

The game of hurling is ranked as one of the fastest and most skilful field games in the world. It is played by a stick, hurley, made of ash wood and a ball, sliotar, made of a cork core or similar viscoelastic materials. Better standardisation of the game equipment requires analysing impacts to quantify precisely the effect of variations in equipment design on the resultant impact force at low and high striking speeds. Therefore, the purpose of the present study was to use a high-speed camera to (1) characterise the impact dynamics in term of impact force magnitude and duration, and (2) investigate whether a relationship exists between the game equipment and the magnitude of the impact force. An air cannon unit (ACU) test rig was set up to cause the sliotar to strike the hurley at predetermined speeds. A high-speed camera operating at 12,500 frames per second (fps) was used to capture 32 experimental impacts covering a range of sliotar and hurley brands, impact locations and impact speeds. The factor ??sliotar brand?? was identified as the most significant factor for the impact force among other main factors and two-factor interactions at a constant speed and it had a significant effect with up to 27?% difference between sliotar brands. It was demonstrated that, at higher impact speeds, the force?Cdeformation curves of the sliotar brands varied significantly, even though similar force?Cdeformation curves have been reported at quasi-static compression and similar COR values at low impact speeds using the standard free-drop test. This is the first known study to characterise the unique, highly non-linear and anisotropic sliotar?Churley impact using high-speed camera technology. It highlights the need for a tighter standard for sliotar materials and manufacturing to increase uniformity between different brands and strongly suggests that the standard free-drop test is not sufficient to characterise and compare game equipment.     

A Hands‐on Activity for Teaching the Poisson Distribution Using the Stock Market

The number of increases a particular stock makes over a fixed period follows a Poisson distribution. This article discusses using this easily‐found data as an opportunity to let students become involved in the data collection and analysis process.     

Intellectualist Aristotelian Character Education: An Outline and Assessment

Since its resurgence in the 1990s, character education has been subject to a bevy of common criticisms, including that it is didactic and crudely behaviorist; premised on a faulty trait psychology; victim‐blaming; culturally imperialist, racist, religious, or ideologically conservative; and many other horrible things besides. Matt Ferkany and Benjamin Creed examine an intellectualist Aristotelian form of character education that has gained popularity recently and find that it is largely not susceptible to such criticisms. In this form, character education is education for practically intelligent virtue, or the intrinsically motivated and psychically harmonious exercise of robust and stable traits involving practical intelligence conducive to individual and collective human flourishing.     

The importance of school culture in supporting student mental health in secondary schools. Insights from a qualitative study

Schools have the potential to provide a place of education and sanctuary for children and young people of all backgrounds. The rise in mental health problems in children and young people in the wake of the COVID-19 pandemic, particularly in relation to growing inequities, means that identifying ways in which schools can help respond to this growing mental health crisis demands urgent attention. This paper reports on case studies carried out in two London comprehensive schools, exploring how aspects of school culture impact (both positively and negatively) on student mental health. Methods comprised in-depth interviews with school staff and parents, focus groups with students and documentary analysis of relevant materials. Fieldwork was conducted during spring 2021 as schools were returning to face-to-face learning following national periods of lockdown. Our study shows how schools might attempt to drive positive mental health outcomes through aspects of school culture and uses a system framework to explore complexities around cause and effect in this area. Key findings include the considerable differences in school mental health provision, challenges in the identification of student mental health needs and the importance of recognising how the mental health of teachers must be considered alongside that of students. Overall, we highlight particular dilemmas of the post-lockdown era that our findings indicate for the education sector, and suggest there may be value in reframing the apparent conflict between ‘attainment gaps’ and personal development, moving towards an educational approach with greater complementarity of these aims.     

Synchronous collaboration competencies in web‐conferencing environments – their impact on the learning process

Based on a three‐semester design‐based research study examining learning and teaching in a web‐conferencing environment, this article identifies types of synchronous collaboration competencies and reveals their influence on learning processes. Four levels of online collaborative competencies were observed – operational, interactional, managerial, and design. The relative importance of students and teachers possessing the different levels of competencies depended on the degree of interactivity in the learning designs being applied. Both misunderstandings and misuses impacted on learning and collaborative processes, with misuses occurring more persistently throughout semesters than misunderstandings. The distinction between developing students’ technical skills and their collaborative capabilities is drawn. Strategies for developing each are recommended.     

A comparison of performance and attitudes in mathematics amongst the ‘gifted’. Are boys better at mathematics or do they just think they are?

This paper explores gender differential performance in ‘gifted and talented’ 9‐ and 13‐year‐olds in a mathematics assessment in England. Boys’ and girls’ attitudes to mathematics and their views about which gender is better at mathematics are also considered. The study employs the use of a matched sample of boys and girls so that school, age and previous achievement in mathematics can be controlled whilst exploring performance on World Class Test items. The main result of this research was that there was no significant gender difference in performance for the 9‐ or the 13‐year‐olds. However, attitudinal differences were found, including a seemingly commonly held stereotypical view of mathematics as a boys’ subject. These results are important since the uptake of higher level mathematically‐based courses by girls is poor. Further findings reveal that where ‘gifted’ girls perform as well as ‘gifted’ boys, their confidence in the subject is lower than their performance might suggest. This work is also discussed in the light of related research findings and in relation to stereotype threat theory.     

Viewing the school environment through multiple lenses: In search of school‐level variables tied to student achievement

The “No Child Left Behind” (NCLB) Act has made schools accountable for assuring adequate yearly progress of students. Therefore, it has become critical to identify school‐level variables that can be controlled to affect student achievement, especially given that, thus far, most school reform efforts have failed to significantly affect student achievement. This study identifies four theoretical constructs, three unique sets of empirical factors (one set for each group: students, teachers, and principals), and seven experiential themes that describe the middle school environment. However, none of these variables show any predictive relationships with achievement, which suggests current federal policies, such as NCLB, are inappropriate and unlikely to lead to improvements in science education in the USA. In addition, students, teachers, and principals were found to perceive the school environment in very different ways, indicating further investigation of student culture is needed to determine appropriate changes that might lead to real improvements in achievement. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 237–254, 2006