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Movement competency and measures of isometric and dynamic strength and power in boys of different maturity status
Get PDFAn understanding of how movement competency, strength, and power interacts with natural growth and maturation is required in order to determine meaningful changes with developing athletes. Isometric and dynamic testing in youth athletes provide insight into the natural development of the force‐velocity (F‐V) spectrum. Two‐hundred and six young male athletes, aged 9‐17 years of age were grouped according to stage of maturation based on their maturity offset which was determined as number of years from peak height velocity (PHV). All participants performed the back‐squat assessment (BSA), isometric mid‐thigh pull (IMTP), countermovement jump (CMJ) and squat jump (SJ) tests. Absolute and scaled force‐time variables were collected from the IMTP, CMJ, and SJ. No significant differences were observed between maturational groups for squat movement competency (p > 0.05). One‐way ANOVA with Bonferroni post‐hoc analysis revealed that increasing maturity led to significant, moderate to large increases in allometrically scaled peak force (PFallo) for all tests (p < 0.05). Multiple stepwise linear regression models revealed IMTP PFallo significantly predicted 34.8% and 41.3% of variance in SJ and CMJ jump height, respectively (p < 0.05). Natural growth and maturation induces positive adaptations to movement competency as well as isometric and dynamic strength and power. Trends from the IMTP, SJ, and CMJ tests indicate the largest differences in strength and power may occur around the adolescent growth spurt despite the large variation in rates of change within the circa‐PHV group
A Fuzzy Cooperative Localisation Framework for Underwater Robotic Swarms
Get PDFThis article proposes a holistic localisation framework for underwater robotic swarms to dynamically fuse multiple position estimates of an autonomous underwater vehicle while using fuzzy decision support system. A number of underwater localisation methods have been proposed in the literature for wireless sensor networks. The proposed navigation framework harnesses the established localisation methods in order to provide navigation aids in the absence of acoustic exteroceptive sensors navigation aid (i.e., ultra-short base line) and it can be extended to accommodate newly developed localisation methods by expanding the fuzzy rule base. Simplicity, flexibility, and scalability are the main three advantages that are inherent in the proposed localisation framework when compared to other traditional and commonly adopted underwater localisation methods, such as the Extended Kalman Filter. A physics-based simulation platform that considers environment’s hydrodynamics, industrial grade inertial measurement unit, and underwater acoustic communications characteristics is implemented in order to validate the proposed localisation framework on a swarm size of 150 autonomous underwater vehicles. The proposed fuzzy-based localisation algorithm improves the entire swarm mean localisation error and standard deviation by 16.53% and 35.17%, respectively, when compared to the Extended Kalman Filter based localisation with round-robin scheduling
Online tracking of ants based on deep association metrics: method, dataset and evaluation
Get PDFTracking movement of insects in a social group (such as ants) is challenging, because the individuals are not only similar in appearance but also likely to perform intensive body contact and sudden movement adjustment (start/stop, direction changes). To address this challenge, we introduce an online multi-object tracking framework that combines both the motion and appearance information of ants. We obtain the appearance descriptors by using the ResNet model for offline training on a small (N=50) sample dataset. For online association, a cosine similarity metric computes the matching degree between historical appearance sequences of the trajectory and the current detection. We validate our method in both indoor (lab setup) and outdoor video sequences. The results show that our model obtains 99.3% ± 0.5% MOTA and 91.9% ± 2.1% MOTP across 24,050 testing samples in five indoor sequences, with real-time tracking performance. In an outdoor sequence, we achieve 99.3% MOTA and 92.9% MOTP across 22,041 testing samples. The datasets and code are made publicly available for future research in relevant domains
An interdisciplinary examination of stress and injury occurrence in athletes
Get PDFThis paper adopts a novel, interdisciplinary approach to explore the relationship between
psychosocial factors, physiological stress-related markers and occurrence of injury in athletes
using a repeated measures design across a 2-year data collection period. At three data
collection time-points, athletes completed measures of major life events, the reinforcement
sensitivity theory personality questionnaire, muscle stiffness, heart rate variability and
postural stability, and reported any injuries they had sustained since the last data collection.
Two Bayesian networks were used to examine the relationships between variables and model
the changes between data collection points in the study. Findings revealed muscle stiffness to
have the strongest relationship with injury occurrence, with high levels of stiffness increasing
the probability of sustaining an injury. Negative life events did not increase the probability
of injury occurrence at any single time-point; however, when examining changes between
time points, increases in negative life events did increase the probability of injury. In
addition, the combination of increases in negative life events and muscle stiffness resulted in
the greatest probability of sustaining an injury. Findings demonstrated the importance of
both an interdisciplinary approach and a repeated measures design to furthering our
understanding of the relationship between stress-related markers and injury occurrence
The acute effects of intracomplex rest intervals on rate of force development and ballistic performance responses following strength-power complex training in talent-identified adolescent rugby players
Get PDFThis study investigated the effects of a strength-power complex on subsequent ballistic activity (BA) performance responses across a profile of jumps in adolescent talent-identified rugby players. Rate of force development (RFD) and BA performance responses was recorded in 22 participants over four intracomplex rest intervals (ICRI) (15s, 30s, 45s, 60s) following a complex of 3 repetitions of back squat @80% 1RM and 7 countermovement jumps (CMJs) in a randomised, counterbalanced design. Within subjects, repeated measures ANOVAs were conducted on peak rate of force development (PRFD), time to peak rate of force development (TPRFD), peak force (PF), and time to a peak force (TPF). Confidence limits were set at ±90% and effect size across the sample (partial ɳ²) was calculated across P1-P4 for all jump profiles. No significant effects were observed across jump profiles or ICRI. The research confirms RFD and BA performance responses were maintained across all jump profiles and each ICRI. In contrast to previous research, the use of minimal ICRI of 15s, 30s, 45s and 60s following strength-power complex training is a practical time-efficient means of maintaining RFD and BA performance responses across jump profiles of seven jumps, which has important implications in practical coaching environments
Embodying Charismatic Affect(If): the Example of Bruce Lee
Get PDFWhile the concept of charisma is widely used in the social sciences, its embodied nature is less thoroughly explored and theorised. This paper revisits the key embodied characteristics of Weber's sociology of charisma and re-interprets these using Shilling's (2005, 2013) umbrella notions of the body as a source and location of and means for society as a way of analysing the idea of the charismatic body as a force for social change. It then draws on a range of embodied concepts to illuminate how charisma is significant channel of infra and inter-corporeal affective interaction between "leaders" and their followers. In particular, Freund's (2009) social synaesthesia and bio-agency, Massumi's (2002) perspective of affect and the moving body, Thrift's (2010) charismatic celebrity, allure and glamour, Mellor and Shilling's (1997) sensual solidarities, and Seyfert's (2012) conception of affectif. To develop and illustrate this perspective of the charismatically affective body in action, the life of film star and martial artist Bruce Lee (1940–1973) is utilised
Networking and strategic planning to enhance small and medium-sized enterprises growth in a less competitive economy
No full textCompetition and day to day fire-fighting prevents small businesses from undertaking the most effective types of strategic planning and networking for growth and innovation. Poor or inappropriate execution of these activities highlights the need for targeted managerial training. Potential explanations for the weak growth of many SMEs focus on the limited use of strategic planning and networking activities. Data from a management survey of SMEs in South East Wales shows that where these activities are undertaken the type of networking and information sought from it is often not that most associated with innovation and growth. Therefore, it may not be their absence per se, but the poor or inappropriate execution of these activities that is the key problem. This deficiency highlights the need for targeted managerial training in these areas
Health and Wellbeing in Higher Education: A Comparison of Music and Sport Students Through the Framework of Self Determination Theory
Get PDFStudents in Higher Education report high levels of mental health issues and
psychological distress. Paradoxical findings on performance-orientated students, such
as athletes and musicians, suggest that the demands of highly skilled vocations may
enhance wellbeing while being detrimental to physical and mental health. To provide
timely and appropriate help, institutions need to understand what areas of health and
wellbeing are compromised in different student groups. In this study, we compared
performance-orientated (music and sport) students to other students and the general
population on a selection of wellbeing (WHO5, PWS, and WEMWBS), mental and
physical health (K10, SF12, and PHQ9), and trait measures (TIPI, LOT-R, and PCS).
Through an online survey (N = 273), data were collected from bachelor and master
students (n = 135 music, n = 67 sport, n = 71 controls). Students’ scores were
compared to the general population, where norm values were available, and analyzed
within and between groups. Multiple regression was performed to investigate trait
measures as predictors of wellbeing. All groups scored significantly below population
norms for wellbeing and mental health. One third were classed as having moderate
to severe depression. Musicians scored higher openness to experience than athletes.
While sport students showed a highly homogenous within-group profile, music students’
scores differed significantly across study courses (e.g., performance and composition).
Predictors for wellbeing were: optimism and emotional stability (all students); additionally
conscientiousness (sport and music); and perceived competence (music only). As
expected, students reported more health and wellbeing issues than general population.
Distinct profiles of wellbeing were apparent for performance-orientated students.
Results are in line with Self Determination Theory and suggest the need for institutions
to embed health and wellbeing into a ‘living curriculum’ to accommodate the needs of
different student groups. The WHO5 emerged as a parsimonious yet sensitive measure
for mental health and wellbeing in student populations
The Role of School Social Support and School Social Climate in Dating Violence Victimization Prevention among Adolescents in Europe
Get PDFThe aim of the article is to show the role of school social support and school social climate in dating violence victimization prevention among adolescents in Europe. Study participants were students from secondary schools (age 13-16) in Spain, Italy, Romania, Portugal, Poland and UK. The analysis in this text concern student with dating experience (n=993) (57.2% of girls and 66.5% of boys). School social support was measured by School Social Climate, Factor 1 Scale (CECSCE) and by Student Social Support Scale (CASSS), subscales teachers and classmates. The association between school social support and different types of dating victimization (physical and/ or sexual dating violence, control dating violence and fear) was measured by calculating the prevalence ratios and their 95% confidence intervals, estimated by Poisson regression models with robust variance. All the models were adjusted by country and by sociodemographic variables. The results show that the average values of all types of social support are significantly lower in young people who have suffered any type of dating violence or were scared of their partner. The likelihood of suffering physical and/or sexual dating violence decreased when school social support increased [PR (CI95%): 0.96 (0.92; 0.99)]. In the same way, the likelihood of fear decreased when school social climate increased [PR (CI95%): 0.98 (0.96; 0.99)].There is an association between school social support and school social climate and experiences of being victim of dating violence among adolescents in Europe. Our results suggest that in the prevention of dating violence building a supportive climate at schools and building / using the support of peers and teachers is important
Effects of a 12-Week Training Program on Isometric and Dynamic Force-Time Characteristics in Pre– and Post–Peak Height Velocity Male Athletes
Get PDFLiterature shows that training children and adolescents can enhance strength and power irrespective of their stage of development; however, the development of the kinetic variables that underpin strength and power performance are typically unreported in youth training studies. Twenty-four pre– and 14 post–peak height velocity (PHV) male athletes were divided into maturity-specific experimental (EXP) and control groups (CON), with the EXP groups completing a twice-weekly, 12-week training program. Force-time characteristics during the isometric midthigh pull (IMTP), countermovement jump, and squat jump tests were quantified at both baseline and after the completion of the 12-week program. Alpha level was set at p 0.05). Analysis of IMTP data revealed that only the post-PHV EXP group significantly increased absolute isometric peak force (PFabs) and peak rate of force development within the IMTP after training. Both EXP groups displayed significant increases in isometric PF at time epochs 0–90, 0–150, 0–200, and 0–250 ms. Data from the dynamic tests indicated that the pre-PHV EXP cohort improved concentric qualities as reflected by increased squat jump height and countermovement jump concentric power. There were no significant changes for any variables across all tests within either CON group (p > 0.05). Maturity-related differences in response to short-term training affects the kinetic variables associated with strength and power performance, but not movement competency in young male athletes