Assessing the reliability and validity of agility testing in team sports: a systematic review

The aims of this systematic review were to: 1) examine the reliability of the reactive agility tests and, 2) analyse the discriminatory validity of the agility tests. A literature search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We explored PubMed, SPORTDiscus and Cochrane Plus databases looking for articles about agility in team sports. After filtering for article relevance, only 42 studies met the inclusion criteria; 37 of which assessed the reliability of agility tests and 22 assessing their validity. Reliability showed a high ICC in almost all studies (range 0.79-0.99) with the exception of two studies. In addition, other studies also assessed the reliability of decision time (ICC=0.95), movement time (ICC=0.92) and decision accuracy (ICC=0.74-0.93), all of which exhibited acceptable reliability. Furthermore, these data show high discriminatory validity, with higher performance players being faster than lower performance level players (mean = 6.4%, range = 2.1-25.3%), with a faster decision time (mean = 23.2%, range = 10.2-48.0%) with the exception of one study, and better decision accuracy (mean = 9.3%, range = 2.5-21.0%). Thus, it can be concluded that reactive agility tests show good reliability and discriminatory validity. However, most agility tests occur in simple contexts whereby only two possible responses are possible. Therefore, future research should consider creating more specific and complex environments which challenge the cognitive process of high-level athletes

Are change of direction speed and agility different abilities from time and coordinative perspectives?

This study aimed to test whether agility and change of direction speed (COD) are independent capacities using the same movement pattern (1) in terms of the completion time and (2) the entropy. Seventeen semi-professional female football players participated in the study. The agility task consisted of a Y-shaped (45° COD) task with three possible exit options (center, right and left) performed pre-planned or in reaction to the movement of two testers (i.e., blocking exit gates). Players’ acceleration was measured using an inertial measurement unit. Entropy was calculated from the acceleration signal and completion time was extracted using a magnet-based timing system. Significantly greater times and lower entropy (p&lt;0.001) were found during agility runs to pre-planned COD runs. Furthermore, weak to moderate correlations were found between COD and agility for both completion time (r = 0.29, p&lt;0.001) and entropy (r = 0.53, p&lt;0.001, r2 = 28.1%). These results highlight that COD speed and agility are independent capacities and skills, and as such, should be tested and trained as distinct, separate qualities. Modifying task constraints including a reactive stimulus (i.e., cognitive factors), is essential for increasing task complexity by altering the biomechanical and coordinative aspects of the action.</jats:p

The Influence of Functional Flywheel Resistance Training on Movement Variability and Movement Velocity in Elite Rugby Players

The aim of this study was to identify the changes in movement variability and movement velocity during a six-week training period using a resistance horizontal forward–backward task without (NOBALL) or with (BALL) the constraint of catching and throwing a rugby ball in the forward phase. Eleven elite male rugby union players (mean ± SD: age 25.5 ± 2.0 years, height 1.83 ± 0.06 m, body mass 95 ± 18 kg, rugby practice 14 ± 3 years) performed eight repetitions of NOBALL and BALL conditions once a week in a rotational flywheel device. Velocity was recorded by an attached rotary encoder while acceleration data were used to calculate sample entropy (SampEn), multiscale entropy, and the complexity index. SampEn showed no significant decrease for NOBALL (ES = -0.64 ± 1.02) and significant decrease for BALL (ES = -1.71 ± 1.16; p < 0.007) conditions. Additionally, movement velocity showed a significant increase for NOBALL (ES = 1.02 ± 1.05; p < 0.047) and significant increase for BALL (ES = 1.25 ± 1.08; p < 0.025) between weeks 1 and 6. The complexity index showed higher levels of complexity in the BALL condition, specifically in the first three weeks. Movement velocity and complex dynamics were adapted to the constraints of the task after a four-week training period. Entropy measures seem a promising processing signal technique to identify when these exercise tasks should be changed

The relevance of social media for user studies in health specialized libraries

A evolução tecnológica da Internet e suas ferramentas vêm se propagando em diferentes tipos de dispositivos eletrônicos, passando pelos tradicionais computadores pessoais, smartphones e smart TVs, contribuindo significativamente para o aumento e transformação do acesso ao conhecimento, a inclusão social por meio da alfabetização tecnológica e a interatividade instantânea. A pesquisa desenvolvida é um estudo de caso sobre a Biblioteca da Escola de Enfermagem (BIBENF) da Universidade Federal do Rio Grande do Sul (UFRGS). Com uma proposta exploratória da realidade quanto à abordagem, a pesquisa possui um caráter quali-quantitativo.Utiliza dados disponibilizados pelo instrumento webmétrico do próprio Facebook para levantar evidências sobre o comportamento informacional dos usuários junto à fanpage da unidade de informação.Conclui que a inclusão das mídias sociais nos estudos de usuários potencializa o conhecimento dos usuários das bibliotecas, traçando seus perfis de forma mais detalhada, identificando necessidades informacionais e compreendendo o comportamento perante a informação divulgada pelas unidades de informação. Estudos de usuários virtuais são importantes ferramentas de gestão para as bibliotecas, pois permitem distinguir com antecipação as demandas informacionais e tecnológicas dos seus usuários, ao mesmo tempo em que permitem direcionar os produtos e serviços oferecidos às necessidades do público, garantindo, dessa maneira, maior eficácia e fidelização.The technological evolution of the Internet and its tools have been propagated in different types of electronic devices, passing through the traditional personal computers, smartphones and smart TVs, contributing significantly to the increase and transformation of access to knowledge, social inclusion through literacy technology and instant interactivity. The research developed is a case study on the Library of the Nursing School (BIBENF) of the Federal University of Rio Grande do Sul (UFRGS). With an exploratory proposal of the reality regarding the approach, the research has a qualitative-quantitative character The data provided by the webmetric instrument of Facebook itself was used to gather evidence about the informational behavior of the users next to the fanpage of the information unit. It is concluded that the influence of social media in user studies adds possibilities for better understanding of users of libraries, tracing their profiles in a more detailed way, identifying informational needs and understanding the behavior towards the information disseminated by the information units. Studies of virtual users are important management tools for libraries, since they allow them to know in advance the informational and technological demands of their users, at the same time as they allow to direct the products and services offered to the needs of the public, thus guaranteeing greater effectiveness and loyalty

Assessment of movement variability and time in a football reactive agility task depending on constraints

The aims of this study were to: (1) analyze time and movement variability in a football (soccer) agility task performed with or without ball, both in the following situations a) reacting to the movement of two players with a single exit gate (R1), b) reacting to the movement of one player with two possible exit gates (R2) and c) not reacting to a stimulus; and, (2) analyze the relationship between time and movement variability. Seventeen semi-professional female football players participated in the study. Acceleration was measured using an inertial measurement unit attached to each player through an elastic belt close to the sacrum. Entropy was calculated from the acceleration signal and time was extracted using a magnet-based timing system. Movement variability was reduced whereas time increased when adding the ball and/or the reaction, finding no differences between R1 and R2. A moderate negative correlation was found between time and movement variability (r=-0.56, p<0.01). Our findings demonstrate that increasing the difficulty and/or the amount of information from the environment, decreased movement variability and increased the time. The measurement of movement variability in addition to time in an agility task can be used to determine the mastery level of players