The relationship between the performance of backstroke start and medicine ball backward throwing

2017 ◽  
Vol 20 ◽  
pp. e57
Author(s):  
R. Nara ◽  
Y. Ikeda ◽  
H. Ichikawa ◽  
D. Sato ◽  
H. Shimojo ◽  
...  
2018 ◽  
Vol 24 (3) ◽  
pp. 192-196 ◽  
Author(s):  
Leonardo Gomes de Oliveira Luz ◽  
Tatiana Durão D`Ávila Luz ◽  
João Valente-dos-Santos ◽  
João Pedro Duarte ◽  
André Filipe Teixeira e Seabra ◽  
...  

ABSTRACT Introduction: Biological maturation has been related to the level of physical activity and motor competence of children. Objectives: This study aimed to: 1) analyze the association between biological maturation and performance in muscular strength tests and 2) examine whether the relationship between maturation and performance in physical tests is mediated by anthropometric variables. Method: The sample was composed of 71 eight-year-old Brazilian girls. Anthropometry considered stature, body mass, waist circumference, estimated fat mass and fat-free mass. Biological maturation was assessed based on the percentage of predicted adult stature. The physical tests consisted of 2-kg medicine ball throw, handgrip strength, sit-ups and standing long jump. Pearson’s correlation test was conducted between the study variables and the last stage consisted of a causal mediation analysis. Results: Biological maturation was significantly associated with the 2-kg medicine ball throw (r=0.52) and handgrip strength (r=0.42) tests. In the 2-kg medicine ball throw, the relationship with maturation was mediated by body mass (total mediation, Sobel’s Test = 2.214, p<0.05) and by estimated lean mass (total mediation; Sobel’s Test = 3.146, p<0.001). In the handgrip strength test, body mass was the only mediating variable (total mediation; Sobel’s Test = 2.251, p<0.05). Conclusions: Advanced maturational status appears to contribute to the performance of prepubescent girls in muscular strength tests in which there is no translocation of total or partial body mass. It is recommended that studies be conducted in other age groups. Level of Evidence III; Study of nonconsecutive patients; without consistently applied reference ‘‘gold’’ standard.


Author(s):  
Emine Kutlay ◽  
Fehime Haslofça ◽  
Ercan Haslofça

In order to monitor training effects and physical developments in elite sports, it may be beneficial to perform anthropometric measurements and physical fitness tests regularly. In this study, the relationship between the anthropometric properties and physical fitness values of elite figure skating athletes were investigated. 21 elite athletes in the 11-16 age group, female (n=12) and male (n=9), participated in the study. Anthropometric measurements were taken in accordance with The International Society for the Advancement of Kinanthropometry (ISAK) protocol. Σ6 and Σ8 skinfold thickness, body fat ratio (BF%), body mass index (BMI), Manouvrier Index (MI), waist/hip ratio and somatotype components in girls Group II, III and in boys Group II were calculated. Also, balance, flexibility, handgrip strength, vertical jump, agility, medicine ball overhead back throw, speed, and endurance tests were applied to all groups. Descriptive statistical analyzes were made using the IBM SPSS 25.0 statistics program. The relationship between variables was calculated by the Pearson Correlation coefficient. The significance level was taken as p<0.01 and p<0.05. In boys, body weight, body height and arm span, sitting height, BMI, humerus breadth and foot length were observed to be associated with all physical fitness parameters (p<0.01, p<0.05), except balance and agility; Girth measurements were related to handgrip strength, vertical jump, overhead medicine ball backward throw, speed and endurance (p<0.01, p<0.05). Negative relationships of the endomorphic feature with flexibility and endurance were determined (p<0.05). In girls, it was found that body weight, body height, and arm span, sitting height and BMI were related to flexibility, handgrip strength, medicine ball overhead back throw (p<0.01, p<0.05); girth measurements were found to be related to flexibility, handgrip strength, vertical jump, overhead medicine ball back throw (p<0.01, p<0.05); also, significant correlations (p<0.01, p<0.05) were found between the handgrip strength and breadth measurements. Assessment of the relationship between morphological features and motor skills with specific field tests and standardized tests performed at regular intervals in athletes can contribute to the athletes' selection and training planning of the relevant federations and orientating towards their goals.<p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0629/a.php" alt="Hit counter" /></p>


Kinesiology ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 87-94 ◽  
Author(s):  
David Valadés ◽  
José Manuel Palao ◽  
Ángel Aúnsolo ◽  
Aurelio Ureña

The aim of this paper was to study the relationship between spike speed and the players’ characteristics, anthropometrics, and strength levels throughout the season for a women’s professional volleyball team. Players from a Spanish first division team performed a battery of tests evaluating anthropometric characteristics, strength performance, and spike speed at the beginning, in the middle, and at the end of one competitive season. The variables were: age; training experience; height; one-hand standing reach height; body mass; body mass index; height of the vertical jump with an approach (spike jump); muscle percentage of arms; 1 repetition maximum (1RM) bench press; 1RM pullover; overhead medicine ball throws for distance using 1, 2, 3, 4, and 5 kg; spike angles; and speed of standing and jump spikes. Results showed that players’ general strength (bench press and pullover) and power parameters (medicine ball throws) increased throughout theseason, while speed of the jump did not improve. The variable that best predicted the jump spike speed at all the three time points in the season was the standing spike speed. The players’ training increased their strength and upper-body power, but these improvements were not transferred to players’ hitting speed ability. Push-pull and throwing exercises were not specific enough to improve the hitting ability of the female senior volleyball players.


1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.


2019 ◽  
Vol 42 ◽  
Author(s):  
Paul Benjamin Badcock ◽  
Axel Constant ◽  
Maxwell James Désormeau Ramstead

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.


Author(s):  
Robert M. Glaeser

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.


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