Analysis on the Time and Frequency Domains of the Acceleration in Front Crawl Stroke

Analysis on the Time and Frequency Domains of the Acceleration in Front Crawl Stroke The swimming involves accelerations and decelerations in the swimmer's body. Thus, the main objective of this study is to make a temporal and frequency analysis of the acceleration in front crawl swimming, regarding the gender and the performance. The sample was composed by 31 male swimmers (15 of high-level and 16 of low-level) and 20 female swimmers (11 of high-level and 9 of low-level). The acceleration was registered from the third complete cycle during eight seconds in a 25 meters maximum velocity test. A position transducer (200Hz) was used to collect the data, and it was synchronized to an aquatic ca…

Visual tasks and stance width influence the spatial magnitude and temporal dynamics of standing body sway in 6- to 12-year old children.

Relationship between body composition and vertical ground reaction forces in obese children when walking.

Abstract Background Obesity is now a serious worldwide challenge, especially in children. This condition can cause a number of different health problems, including musculoskeletal disorders, some of which are due to mechanical stress caused by excess body weight. The aim of this study was to determine the association between body composition and the vertical ground reaction force produced during walking in obese children. Methods Sixteen children participated in the study, six females and ten males [11.5 (1.2) years old, 69.8 (15.5) kg, 1.56 (0.09) m, and 28.36 (3.74) kg/m 2 of body mass index (BMI)]. Total weight, lean mass and fat mass were measured by dual-energy X-ray absorptiometry and…

Gender differences in bicycle sharing system usage in the city of Valencia

Abstract Bicycle sharing systems (BSS) in cities are an environmentally friendly alternative to fossil-fuel-based transport. Among the different factors that influence its use, the scientific literature points out that there are gender differences in the frequency of trips made. The present study analysed the movements of men and women who use the BSS in the city of Valencia during weekdays. Our database contained a total of 5,300,328 trips by users over a period of 4 years. Ridership networks were constructed through user's trips (arcs) between the bicycle exchange stations (nodes). Different parameters of centrality and density of the generated networks were calculated, and the Voronoi sp…

The impact factor as a measuring tool of the prestige of the journals in research assessment in mathematics

The (2-year) Impact Factor of Thomson-Reuters (IF) has become the fundamental tool for analysing the scientific production of academic researchers in a lot of countries. In this article we show that this index and the ordering criterion obtained by using it are highly unstable in the case of mathematics, to the extent that sometimes no reliability can be assigned to its use. We explain the reasons of this behaviour by the specific properties of the mathematical journals and publications, attending mainly the point of view of the researchers in pure mathematics. Using the Journal Citation Report list of journals as a source of information, we analyse the stability in the position of the math…

Scientific literature analysis of Judo in Web of Science®

Background & Study Aim: Although judo is a sport with great tradition that is practised worldwide, the state of the art and scientific advances have not been analysed from a bibliometric point of view up to now. The aim of the present article is the status of the scientific production, collaboration, and impact of scientific papers on judo, as well as the most active research groups working on this topic. Material & Methods: Our analysis was based on documents retrieved from the Science Citation Index and Social Science Citation Index. Bibliometric analysis and network construction were performed using Histcite and Bibexcel software. Results: As a result, 383 original papers and scientific …

The Impact of COVID-19 on Sport in Twitter: A Quantitative and Qualitative Content Analysis

The spread of the SARS-CoV-2 virus has transformed many aspects of people’s daily life, including sports. Social networks have been flooded on these issues. The present study aims to analyze the tweets produced relating to sports and COVID-19. From the end of January to the beginning of May 2020, over 4,000,000 tweets on this subject were downloaded through the Twitter search API. Once the duplicates, replicas, and retweets were removed, 119,253 original tweets were analyzed. A quantitative–qualitative content analysis was used to study the selected tweets. Posts dynamics regarding sport and exercise evolved according to the COVID-19 pandemic and subsequent lockdown, shifting from consideri…

Physical Activity and Exercise: Text Mining Analysis

It is currently difficult to have a global state of the art vision of certain scientific topics. In the field of physical activity (PA) and exercise, this is due to information overload. The present study aims to provide a solution by analysing a large mass of scientific articles using text mining (TM). The purpose was to analyse what is being investigated in the PA health field on young people from primary, secondary and higher education. Titles and abstracts published in the Web of Science (WOS) database were analysed using TM on 24 November 2020, and after removing duplicates, 85,368 remained. The results show 9960 (unique) words and the most frequently used bi-grams and tri-grams. A co-…

Screen time among Spanish university students with disabilities: a self-organizing maps analysis

Abstract Background:Screen time can play a significant role in the health and quality of life of people with disabilities.However, there is a lack of studies on this issue among people with disabilities, and even fewer in the universitysetting. Thus, the aim of our study was to explore the relationships between screen time, disability grade, bodymass index (BMI), physical activity and sociodemographic variables (gender and socioeconomic status) in universitystudents with different disabilities. Methods:A cross-sectional study was conducted on a sample of 1091 students with disabilities from 55 Spanishuniversities. Instruments used for data gathering were the Adolescent Sedentary Activity Qu…

Postural Control Mechanisms in Healthy Adults in Sitting and Standing Positions

This study explored differences in the center of pressure in healthy people in a sitting and standing position and with eyes open and closed. With this purpose, 32 healthy participants (16 men, 16 women; M age = 25.2 yr., SD = 10.0, range = 18–55) were measured with an extensiometric force plate. Using a two–way repeated-measures multivariate analysis of variance (MANOVA), the root mean square, velocity, range, and sway, in both visual conditions, had higher values in the standing task than in the sitting task. In the frequency domain, the low-frequency band had higher values during the standing task. For control mechanism variables, mean distance and time were greater when standing while …

Effects of electrical stimulation on muscle trophism in patients with hemophilic arthropathy.

Abstract Gomis M, Gonzalez L-M, Querol F, Gallach JE, Toca-Herrera J-L. Effects of electrical stimulation on muscle trophism in patients with hemophilic arthropathy. Objective To determine changes occurring in the cross-sectional area, electromyography (EMG) activity, and the strength of the biceps brachii after an 8-week period of bilateral training with surface muscle electrical stimulation in patients with hemophilic arthropathy. Design Controlled trial. Setting Coagulopathy unit, university hospital. Participants Volunteer subjects (N=30) participated in this study: 15 with severe hemophilia A (hemophilic group) and 15 nonhemophilic control subjects (control group). Interventions The he…

Relation between physical activity and academic performance in 3rd-year secondary education students

The main aim of this study was to analyze the relationship between the amount of physical activity and academic performance in 3rd-year secondary education students. The sample was taken from three secondary schools in the area of Barcelona. 284 students (158 girls, 126 boys) with an average age of 14.7 yr. participated. The International Physical Activity Questionnaire was used by students to self-report their amount of physical activity. Students’ academic records were obtained for comparisons. Results showed that there was a linear relationship between academic performance and physical activity; nevertheless, there was a trend to stronger correlation when modeling the relationship betwee…

Rehabilitation and Improvement of the Postural Function

Posture refers to the position of different body segments at a given time which can be modified through joint mobilization and the action of the neuromuscular system. Maintaining balance during bipedal quiet stance requires complex mechanisms from the postural control system in order to keep the vertical projection of the centre of mass (COM) within the base of support [1]. To achieve this aim, the centre of pressure (COP) plays a crucial role to compensate for any deviations of the COM, which can generate imbalance if they move beyond the limits of the base of support. The ability to control the COM depends on internal body representation in space. Internal representation is acquired by me…

Validation of the use of Actigraph GT3X accelerometers to estimate energy expenditure in full time manual wheelchair users with spinal cord injury.

Study design: Cross-sectional validation study. Objectives: The goals of this study were to validate the use of accelerometers by means of multiple linear models (MLMs) to estimate the O2 consumption (VO2) in paraplegic persons and to determine the best placement for accelerometers on the human body. Setting: Non-hospitalized paraplegics’ community. Methods: Twenty participants (age=40.03 years, weight=75.8 kg and height=1.76 m) completed sedentary, propulsion and housework activities for 10 min each. A portable gas analyzer was used to record VO2. Additionally, four accelerometers (placed on the non-dominant chest, non-dominant waist and both wrists) were used to collect second-by-second a…

An author keyword analysis for mapping Sport Sciences

[EN] Scientific production has increased exponentially in recent years. It is necessary to find methodological strategies for understanding holistic or macro views of the major research trends developed in specific fields. Data mining is a useful technique to address this task. In particular, our study presents a global analysis of the information generated during last decades in the Sport Sciences Category (SSC) included in the Web of Science database. An analysis of the frequency of appearance and the dynamics of the Author Keywords (AKs) has been made for the last thirty years. Likewise, the network of co-occurrences established between words and the survival time of new words that have …