Detecting changes in the basin of attraction of a dynamical system: Application to the postural restoring system

A method that provides athree-dimensional representation ofthe basin ofattraction of a dynamical system from experimen tal data was applied tothe problem ofdynamic balance restoration. The method isbased onthe density ofthe data onthe phase space ofthe system under study and makes use ofmodeling and numerical curve fittingtools.For the dynamical system ofbalance restora tion,the shape and the size of the basin of attraction depend on the dynamics of the postural restoring mechanisms and contain important information regarding the biomechanical,as well as the neuromuscular condition of the individual. The aim ofthis work was toexamine the ability ofthe method todetect, through the observed changes inthe shape and/or the size ofthe calculated basins of attraction, (a)the inherent differences between different systems (in the current application, postural restoring systems of different individuals)and (b)induced chan ges in the same system (thepostural restoring system of an individual).The results ofthe study confirm the validity of the method and furthermore justify its robustness

Title Page Title: Validating the use of a dumbbell to measure body sway in female Olympic air pistol shooting Other authors' email addresses

Abstract: The present study validates use of a dumbbell to simulate the air pistol in female Olympic shooting, examining, at the same time, the relation between body sway and performance. The study's participants were 23 senior female Olympic pistol shooters who competed at a Spanish air pistol championship. The participants' performance was measured at competition while their COP movements were recorded during two static bipodal balance tests which were performed the day previous to the competition, during the official training time and at the training stands. During one of the tests a 1.5 kg dumbbell was used to simulate the pistol. The calculated Pearson product moment correlations for all variables that refer to the movement of the COP revealed statistically significant correlations between the two tests. Statistically significant inverse linear correlations were also found between performance and COP movements regarding both tests: strong correlations regarding COP movement amplitudes and moderate correlations regarding COP velocities. The study concludes that a) a dumbbell can be validly used to simulate the pistol in female Olympic air pistol shooting, and b) specific balance training programs should be taken into account in order to improve performance in female air pistol shooting

Finger Flexor Force Influences Performance in Senior Male Air Pistol Olympic Shooting

The ability to stabilize the gun is crucial for performance in Olympic pistol shooting and is thought to be related to the shooters muscular strength. The present study examines the relation between performance and finger flexor force as well as shoulder abduction isometric force in senior male air pistol shooting. 46 Spanish national level shooters served as test subjects of the study. Two maximal force tests were carried out recording handgrip and deltoid force data under competition conditions, during the official training time at national Spanish championships. Performance was measured as the total score of 60 shots at competition. Linear regressions were calculated to examine the relations between performance and peak and average finger flexor forces, peak and average finger flexor forces relative to the BMI, peak and average shoulder abduction isometric forces, peak shoulder abduction isometric force relative to the BMI. The connection between performance and other variables such as age, weight, height, BMI, experience in years and training hours per week was also analyzed. Significant correlations were found between performance at competition and average and peak finger flexor forces. For the rest of the force variables no significant correlations were found. Significant correlations were also found between performance at competition and experience as well as training hours. No significant correlations were found between performance and age, weight, height or BMI. The study concludes that hand grip strength training programs are necessary for performance in air pistol shooting

Finger Flexor Force Influences Performance in Senior Male Air Pistol Olympic Shooting.

The ability to stabilize the gun is crucial for performance in Olympic pistol shooting and is thought to be related to the shooters muscular strength. The present study examines the relation between performance and finger flexor force as well as shoulder abduction isometric force in senior male air pistol shooting. 46 Spanish national level shooters served as test subjects of the study. Two maximal force tests were carried out recording handgrip and deltoid force data under competition conditions, during the official training time at national Spanish championships. Performance was measured as the total score of 60 shots at competition. Linear regressions were calculated to examine the relations between performance and peak and average finger flexor forces, peak and average finger flexor forces relative to the BMI, peak and average shoulder abduction isometric forces, peak shoulder abduction isometric force relative to the BMI. The connection between performance and other variables such as age, weight, height, BMI, experience in years and training hours per week was also analyzed. Significant correlations were found between performance at competition and average and peak finger flexor forces. For the rest of the force variables no significant correlations were found. Significant correlations were also found between performance at competition and experience as well as training hours. No significant correlations were found between performance and age, weight, height or BMI. The study concludes that hand grip strength training programs are necessary for performance in air pistol shooting

Examples of body sway graph showing the COP movements of the same participant, as recorded on the force platform plane.

<p>(a): By use of a pistol, (b) by use of a dumbbell simulating a pistol. The total COP movement can be assumed to be included within an ellipse, the principal axis of which is rotated in respect to X axis.</p

Influence of socio-demographic correlates on the adherence to physical activity recommendations in adults aged from 15 to 74 years, Madrid, Spain

Fundamento: Conocer el nivel de adherencia de las personas a las recomendaciones de actividad física (AF) es de interés socio-sanitario. El objetivo del presente estudio fue describir el nivel de adherencia a las recomendaciones de AF por los adultos de la Comunidad de Madrid, así como analizar su asociación con posibles determinantes socio-demográfi-cos. Métodos: En el presente estudio transversal se realizó una encuesta telefónica a una muestra de 1.500 personas de 15 a 74 años de la Comunidad de Madrid. La AF se evaluó con la versión 2 del Global Physical Activity Questionnaire (GPAQv2) y se clasificó en tres niveles de intensidad (bajo, moderado y alto), según procedimiento de análisis del GPAQv2. Las variables socio-demográficas estudiadas fueron: sexo, edad, nivel de estudios, ocupación, estado civil, consumo de tabaco y salud percibida. Para analizar la asociación entre las características socio-demográficas y la AF, se realizaron análisis de regresión logística multinomial. Resultados: El 82% de los varones y 78% de las mujeres (80% en total) tenían un nivel global de AF moderado o alto, y el 40,1% y el 22,6% (31% en total) de los varones y mujeres, respectivamente, alcanzó las recomendaciones de AF en el tiempo libre. Tenían más probabilidades de no alcanzar las recomendaciones de AF los participantes con estudios superiores (OR: 2,05; 95%IC: 1,48-2,86), los fumadores habituales (OR: 1,41; 95%IC: 1,04-1,90) y los que percibían su salud como mala (OR: 3,58; 95%IC: 2,39-5,38). En cuanto a la edad fueron las personas del grupo entre 35-44 años las que tenían menos probabilidades de no cumplirlas (OR: 0,61; 95%IC: 0,39-0,95) y 45-54 (OR: 0,52; 95%IC: 0,32-0,83). Conclusiones: El 20% de las personas de la Comunidad de Madrid que tienen entre 15 y 74 años no cumplen con las recomendaciones mínimas de AF, y cuando se considera la AF realizada exclusivamente durante el tiempo libre se llega al 69% de los participantes que no alcanzan las recomendaciones de AF. El nivel de estudios, el hábito de fumar y la percepción de tener mala salud influyen en los niveles de AF.Background: To know the adherence to physical activity recommendations of the population is of clinical and social interest. The aim of this study was to estimate the proportion of Spanish adults adhering to the physical activity recommendations, and to examine the influences of socio-demographic correlates. Methods: In the present cross-sectional study we conducted a telephone survey of 1,500 Spanish adults (15-74 years old) from Madrid (Spain). Physical activity (work place, transport and leisure time) was assessed with the version 2 of the Global Physical Activity Questionnaire (GPAQv2). Participants were categorized in three physical activity levels (low, moderate and high). The socio-demographic correlates included: gender, age, educational level, employment status, marital status, smoking status, and self-perceived health. The association between socio-demographic factors and physical activity was examined with multinomial logistic regression analysis. Results: A total of 82% of men and 78% of women (total 80%) had moderate to high levels of physical activity, yet, when considering the leisure time physical activity, only 40,1% of mean and 22,6% of women (total 31.1%) reach the recommendations. Participants with university degree (OR: 2.05; 95%IC: 1.48-2.86), those who were smokers (OR: 1.41; 95%IC: 1.04-1.90), and those who perceived their health as bad (OR: 3.58; 95%IC: 2.39-5.38) were more likely to not to reach the recommendations. In contrast, those participants aged 35-44 years (OR: 0.61; 95%IC: 0.39-0.95) and 45-54 years (OR: 0.52; 95%IC: 0.32-0.83) were less likely not to reach the recommendations. Conclusions: The 20% of adults from Madrid did not reach the physical activity recommendations, and when considering only leisure time physical activity, only 69% reached the recommendations. The findings suggest that the educational level, smoking status, and the self-perceived health seem to be key determinants. There is a large diversity in the physical activity levels in the population subgroup; therefore, there is a need of developing socialecological approaches to physical activity promotion.Estudio parcialmente financiado por el Ministerio de Ciencia y Tecnología (RYC-2010-05957)

Linear correlations between performance and a) length of the COP ellipse principal axis in dumbbell shooting, b) maximum COP displacement on the X axis in pistol shooting, c) experience and d) training.

<p>Coefficient of variation = SD/M×100.</p><p>*Level of significance p<0.05,</p><p>**Level of significance p<0.01.</p

Pearson interclass correlations for the variables that refer to the movement of the COP, for the data of both tests.

<p>Level of significance p<0.001.</p

Mean (± s) values of the participants’ characteristics.

<p>Mean (± s) values of the participants’ characteristics.</p

Hyperandrogenic athletes: performance differences in elite-standard 200m and 800m finals

Summarization: The purpose of this study was to examine whether the difference in elite-standard track and field performance between women athletes with and without hyperandrogenism reaches the 10–12% difference in performance between men and women, using only results from elite-standard track and field final competitions. Officially available data from two hyperandrogenic women (Caster Semenya and Dutee Chand) were compared with the characteristic performance of 200m and 800m elite-standard finals. The finishing times of Caster Semenya, before her ineligibility to compete in 2009 and after the suspension of the 2011 IAAF Hyperandrogenism Regulations were found to be respectively 1.24% and 1.49% faster than the predicted performance in 800m finals. When compared with the result of the second classified, the difference was respectively 0.65% and 2.08%. The analysis of the finishing times of Dutee Chand did not lead to any conclusions due to the lack of available data. The present study indicates that the percentage difference in performance between women with and women without hyperandrogenism does not reach the 3% difference requested by the Court of Arbitration for Sport for the reinstatement of the Hyperandrogenism Regulations, neither does it reach the 10% accepted range of difference in performance between men and women.Παρουσιάστηκε στο: Journal of Sports Science