Kinematic analysis of hip and knee rotation and other contributors to ballet turnout

Turnout, or external rotation (ER) of the lower extremities, is essential in ballet. The purpose of this study was to utilise physical examination and a biomechanical method for obtaining functional kinematic data using hip and knee joint centres to identify the relative turnout contributions from hip rotation, femoral anteversion, knee rotation, tibial torsion, and other sources. Ten female dancers received a lower extremity alignment assessment, including passive hip rotation, femoral anteversion, tibial torsion, weightbearing foot alignment, and Beighton hypermobility score. Next, turnout was assessed using plantar pressure plots and three-dimensional motion analysis; participants performed turnout to ballet first position on both a plantar pressure mat and friction-reducing discs. A retro-reflective functional marker motion capture system mapped the lower extremities and hip and knee joint centres. Mean total turnout was 129±15.7° via plantar pressure plots and 135±17.8° via kinematics. Bilateral hip ER during turnout was 49±10.2° (36% of total turnout). Bilateral knee ER during turnout was 41±5.9° (32% of total turnout). Hip ER contribution to total turnout measured kinematically was less than expected compared to other studies, where hip ER was determined without functional kinematic data. Knee ER contributed substantially more turnout than expected or previously reported. This analysis method allows precise assessment of turnout contributors.     

Influence of Session Context on Physical Activity Levels Among Russian Girls During a Summer Camp

Purpose: This study investigated the effect of summer camp session context on Russian girls’ physical activity (PA). Method: Girls (n = 32, M_age = 10.7 years, SD = 0.6 years) from a resident summer camp taking place in the Vologda Region of Russia were exposed to 1 session context/day (i.e., free play, organized with no choice, organized with choice) on Wednesday, Thursday, and Friday for 3 weeks, with the context order counterbalanced across the 3 weeks. The organized session sport/game changed weekly. The primary outcome was accelerometer-assessed PA. Repeated-measures mixed models were used to analyze all outcome data. Results: Findings showed that girls spent a greater percentage of session time (%time) in moderate-to-vigorous PA (p < .001; effect sizes between free play and organized with no choice and organized with choice, respectively = .60, .42) and moderate PA (p < .001; effect size = .57, .39) and a lower %time in light PA (p < .001; effect size = .55, .52) in organized PA contexts compared with free play. Conclusions: This study provides novel findings in a Russian setting, suggesting that a well-planned, organized camp session can elicit higher PA levels in girls, relative to a free-play session.     

Sport disciplines,types of sports,and waist circumference in young adulthood – a population-based twin study

Purpose: The benefits of physical activity (PA) in preventing abdominal obesity are well recognized, but the role of different sport disciplines remains open. We aimed, therefore, to investigate how participation in different sport disciplines, and the number and types of sports engaged in are associated with waist circumference (WC) in young adulthood. Methods: This population-based cohort study comprised 4027 Finnish twin individuals (1874 men), with a mean age of 34 y (32–37), who answered a survey, including self-measured WC. We extracted the number and identified the types (aerobic, power, and mixed) of the different sport disciplines respondents reported participating in. Results: The number of sport disciplines participated in was inversely associated with WC, the linear decrease averaging 1.38?cm (95% CI 1.10–1.65) per each additional sport discipline. The result persisted after adjustment for the main covariates, such as volume of PA and diet quality. Among dizygotic twin pairs discordant for sports participation (0–2 vs. 5 or more disciplines), the mean within-pair difference in WC was 4.8?cm (95% CI 0.4–9.1) for men and 11.2?cm (95% CI 4.4–18.0) for women; among discordant monozygotic pairs, no differences were observed. In men, all three types of sports were individually associated with smaller WC, while in women, only mixed and power sports showed this association. Conclusions: Participation in several sport disciplines and sport types was associated with smaller WC among young adults in their mid-30s. Shared genetic background may explain some of the associations.     

An analysis of the relationship between the linear hammer speed and the thrower applied forces during the hammer throw for male and female throwers

The purpose of this study was to investigate the relationship between the cable force and linear hammer speed in the hammer throw and to identify how the magnitude and direction of the cable force affects the fluctuations in linear hammer speed. Five male (height: 1.88 +/- 0.06 m; body mass: 106.23 +/- 4.83 kg) and five female (height: 1.69 +/- 0.05 m; body mass: 101.60 +/- 20.92 kg) throwers participated and were required to perform 10 throws each. The hammer's linear velocity and the cable force and its tangential component were calculated via hammer head positional data. As expected, a strong correlation was observed between decreases in the linear hammer speed and decreases in the cable force (normalised for hammer weight). A strong correlation was also found to exist between the angle by which the cable force lags the radius of rotation at its maximum (when tangential force is at its most negative) and the size of the decreases in hammer speed. These findings indicate that the most effective way to minimise the effect of the negative tangential force is to reduce the size of the lag angle.     

The contribution of attentional processes to calculation skills in second and third grade in a typically developing sample

Attention is an important, multifaceted cognitive domain that includes many key cognitive processes involved in learning. This study aimed to identify the predictive links between different components of attentional skills and core calculation skills development, using two standardized measures assessing calculation (AC-MT 6–11) and attention skills (CAS) in a sample of 143 typically developing children of age range from 7.6 years to 9.4 years. The results showed that in 2nd grade, selective visuo-spatial attention emerged as an important predictor in the written calculation task, while the ability to inhibit distracting information seemed to better predict accuracy in oral calculation. In 3rd grade, visuo-spatial components of attention emerged as no longer predictive, whereas planning and active visuo-spatial attention abilities emerged as predictive of accuracy in the oral calculation task. These results confirm previous findings about the contribution that attentional skills may have in calculation skills development, supporting evidence for progressive automation attentional components over time.

     

Psychometric characteristics of the Persian version of the Multidimensional School Anger Inventory–Revised

The Multidimensional School Anger Inventory–Revised (MSAI-R) is a measurement tool to evaluate high school students' anger. Its psychometric features have been tested in the USA, Australia, Japan, Guatemala, and Italy. This study investigates the factor structure and psychometric quality of the Persian version of the MSAI-R using data from an administration of the inventory to 585 Iranian high school students. The study adopted the four-factor underlying structure of high school student anger derived through factor analysis in previous validation studies, which consists of: School Hostility, Anger Experience, Positive Coping, and Destructive Expressions. Confirmatory factor analysis of this four-factor model indicated that it fit the data better than a one-factor baseline model, although the fit was not perfect. The Rasch model showed a very high internal consistency among items, with no item misfitting; however, our results suggest that to represent the construct sufficiently some items should be added to Positive Coping and Destructive Expression. This finding is in agreement with Boman, Curtis, Furlong, and Smith's Rasch analysis of the MSAI-R with an Australian sample. Overall, the results from this study support the psychometric features of the Persian MSAI-R. However, results from some test items also point to the dangers inherent in adapting the same test stimuli to widely divergent cultures.     

Effect of the kinesthetic conflict on promoting scientific reasoning

The importance of the kinesthetic-cognitive conflict (bodily experience that contradicts cognition) in the development of thinking is rooted in Piaget's theory. This article presents three studies which demonstrate the efficiency of the kinesthetic conflict in promoting the understanding of three scientific concepts among children aged 5–12. The first study examines the effect of the kinesthetic conflict on promoting the concept of length in children aged 4.5–5.5 years; the second study compares the effect of four types of cognitive conflicts—two physical ones (visual and kinesthetic) and two social ones (between peers and between children and adults)—on promoting the concept of balance among children aged 5–6 years; and the third study compares the effect of the kinesthetic conflict with the visual conflict on promoting the concept of speed among sixth graders. In all three studies, the kinesthetic conflict was found to be the most efficient in causing a significant cognitive change. The results support Piaget's theory which determines that scientific thinking begins with the sensomotoric experience of the physical surroundings. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 1083–1099, 1997.