The assessment of a world-ranked wheelchair sprinter aerodynamics analysis by computer fluid dynamics

Aerodynamics can play an important role in the performance of a wheelchair spinter. The aim of this thesis was to analyse the aerodynamics of a wheelchair sprinter by computer fluid dynamics. This thesis comprises a series of four studies (a review of the literature and three empirical studies). The studies aimed to: (i) review the literature on aerodynamics in wheelchair racing; (ii) compare two different helmets (road vs time trial) at several speeds and head positions by CFD. (iii) assess the aerodynamics in different key-moments of the stroke cycle by CFD; (iv) compare the mechanical power and energy cost of transportation delivered by an elite wheelchair sprinter in key-moments of the stroke cycle. The main conclusions were: (i) there is a lack of research on wheelchair racing aerodynamic’s assess by CFD; (ii) a time trial helmet imposed lower drag keeping a neck hyperextension; (iii) the aerodynamics of a wheelchair racing athlete varied over the different phases of the stroke cycle; (iv) the mechanical power and energy cost in elite wheelchair racing varied in different phases of the stroke cycle. The main conclusion of this thesis was that it is possible to enhance the aerodynamics of a wheelchair sprinter by selecting the best sport garement and equipment, as well as keeping a good body alignment in the key-phases of the stroke cycle.A analise da aerodinâmica desempenha um papel determinante nas provas de velocidade em cadeiras de rodas. Assim, o objetivo desta tese passou por analisar a aerodinâmica de um sujeito das provas de velocidade em cadeiras de rodas, com recurso à análise computacional de fluidos. Para tal, foram realizados quatro estudos, uma revisão de literatura e três estudos empíricos. Foram objetivos dos estudos: (i) rever a literatura quanto ao estudo da aerodinâmica das provas de velocidade em cadeiras de rodas; (ii) comparação de dois capacetes do tipo contrarrelógio e pista em duas posições (olhar em frente e olhar para baixo); (iii) comparação aerodinâmica entre as diferentes fases de um ciclo de puxada com recurso às simulações numéricas; (iv) estimativa da potência mecânica e custo energético num sprinter das provas de velocidade em cadeiras de rodas através de procedimentos analíticos e simulações numéricas. As principais conclusões obtidas foram que: (i) existe pouca literatura e conhecimento acerca das provas de velocidade em cadeiras de rodas, nomeadamente no estudo da aerodinâmica com recurso às simulações numéricas; (ii) os capacetes contrarrelógio são mais efetivos desde que o atleta mantenha o olhar em frente tanto quanto possível; (iii) a aerodinâmica de um atleta das provas de velocidade em cadeiras de rodas variou nas diferentes fases do ciclo de puxada; (iv) a potência mecânica e custo energético foram maiores na fase da pegada, seguida da largada e por fim a fase de recuperação. A principal conclusão desta tese é que torna-se possível melhorar a aerodinâmica de um sujeito das provas de velocidade em cadeiras de rodas através do correto uso do capacete ideal e mantendo tanto quanto possível o alinhamento e sincronização corporal durante as puxadas

The physical activity and exercise as key role topic in sports medicine for old people quality of life

The body composition varies with ageing. There are phases where the body grows, fills (increase in body mass), maintaining, and, finally, declining of the body mass (essentially derived from aging). The elderly population has a important representation in age pyramids. Furthermore, this population has come to have a greater representation in the age pyramids (essentially developed countries). The age-related changes over time lead to reduced adaptability, changes in functional capacity (such as autonomy and independency) and even, eventually, death [1]. The sedentarism is associated with the decline of physiological systems. The diseases increase, the decreasing autonomy, independency and quality of life are typically observed in aged populations [2]. These mostly result in higher disability levels, dependency, and higher probability of diseases incidence [3]. With low levels of physical activity, the increase in body fat levels is the main body composition outcome. Normally, this increase in body fat is also characterized by an increase in abdominal circumference and reduction in lean mass (essentially a decrease in muscle mass) [4]. The association between physical activity, exercise and positive health benefits has been clear [5], with a consensus that individuals physically active seem to enjoy a longer and better quality life in comparison to less active individuals [1,6]. Additionally, the physically active lifestyles have been associated with better functioning of the cardiovascular, respiratory, and muscular systems, as well as reduced risks of morbidity and mortality. These health-related problems have been identified in obese people with chronic diseases. Regarding physiology, we found scientific evidence in favour of the contribution of physical activity as therapeutic strategy to prevent the functional decrease in the cardiovascular system, sarcopenia, loss in the bone mineral mass density, increased blood pressure, reduced insulin resistance and glucose intolerance, and increased serum triglyceride levels. Additionally, the physical activity and exercise positively influence age-related changes in metabolism function; has a protective role against unfavourable changes in body composition, reducing weight gain, and fat mass and increasing fat-free massThis research was founded by the Higher Institute of Educational Sciences of the Douro and by national funds (FCT—Portuguese Foundation for Science and Technology) under the project UIBD/DTP/04045/2020.info:eu-repo/semantics/publishedVersio

Youth’s physical activity and fitness from a rural environment of an Azores Island

This study aimed to characterize and compare physical activity (PA) and fitness levels by sex in 109 students of a rural environment. The participants were between 15 and 20 years old, from the Santa Maria High School in the Azores’ Santa Maria island. PA levels were assessed by International Physical Activity Questionnaire (IPAQ)-short form. The physical fitness was evaluated by the Fitnessgram battery tests. The sample of this study were physically active, 67.9% were classified with high and moderate PA levels. Regarding the sex comparisons, no significant differences between PA levels were founded. However, males presented higher values of vigorous physical activity, whereas females spent more time in moderate activity, such as walking. Moreover, females had more time in sitting positions during the week and weekend. Regarding the physical fitness levels, males presented significantly higher performances in the upper strength (p < 0.001) and aerobic capacity tests (p < 0.001), whereas females showed higher values in the sit and reach test (p < 0.001), in the trunk lift test (p < 0.005), and in the fat mass values (p < 0.001). It seems reasonable to assume that there is a sociodemographic influence on the PA and physical fitness levels in our sample. We may speculate that rural life provides more opportunities for youth for being physically active than urban life. No differences were founded between sexes for physical activity. However, differences were found between sex for strength, flexibility, cardiorespiratory fitness, and body composition. That might be explained by the biological differences and the type of physical activity habits that each sex use to have in rural environmental.This work is supported by National Funds through FCT—Foundation for Science and Technology under the project UID04045/2020 and was approved by the Education Regional Direction with process number DSP/15-29.info:eu-repo/semantics/publishedVersio

Study of postural misalignments between sex, school cycle and physical activity

This study aimed to characterize and compare postural behaviour between gender, school cycles and PA levels in 213 students, aged between 10 and 20 years, from Escola Básica e Secundária de Santa Maria. Postural assessment was made through visual scan analysis in a symmetrograph and the Adams test. PA level assessment was made using the IPAQ. Postural behaviour presented high percentages of imbalances in both sexes, with the highest prevalence in the head lateral flexion, shoulders level asymmetry, scoliosis, gibbosity, forward head and protracted shoulders. Lumbar scoliosis was significantly related to pelvic asymmetry (p < .001), protracted shoulders were related to forward head (p = .010) and dorsal hyperkyphosis (p = .048) and lumbar hyperlordosis was more prevalent in subjects with pelvic anteversion (p < .001). Dorsal hyperkyphosis manifested in males with a markedly higher prevalence than females (p = .006). Postural imbalances were present at all ages, with pelvic anteversion decrease (p = .028) with school cycles progression. Our sample proved to be physically active with 73.9% categorized with high and moderate levels of PA. Higher PA levels where related to forward head lower percentages (p = .006). It should be highlighted the importance of postural assessment school students.This work is supported by National Funds through FCT - Foundation for Science and Technology under the project UID04045/2020 and was approved by the Education Regional Direction with process number DSP/15-29

On Redefining the Body Image Satisfaction Questionnaire: A Preliminary Test of Multidimensionality

The aim of the present study was to examine the Body Image Satisfaction Questionnaire (BISQ) as a ultidimensional instrument, designed to measure individuals’ body image satisfaction. A sample of 790 Portuguese healthy adults (female = 399; male = 391) aged 18 and 49 years old (M = 28.61, SD = 7.97) completed the BISQ. Exploratory factor analysis of the BISQ provided initial psychometric validity for a five-factor model assessing five dimensions of body image, namely, face, upper torso, lower torso, lower body, and overall body appearance. Confirmatory factor analysis supported this five-correlated model, in which a bifactor model provided the best fit to the data, defining a body image satisfaction factor and five specific factors. The BISQ clearly distinguished between various dimensions of body image satisfaction and showed satisfactory psychometric quality through factor analyses. This measure may have a broad application for research and practice, as a tool for capturing individual body image satisfactioninfo:eu-repo/semantics/publishedVersio

Habitual physical activity patterns of pre-school children from Bragança

The increase in the prevalence of overweight in children is commonly associated with their low levels of physical activity (PA). In fact, young people who have higher levels of PA over several years tend to have lower rates of overweight than their less active peers. Thus, it becomes of the utmost importance to promote the practice of regular PA among children. In this context, the aims of this study were to compare the number of steps done by children during the weekdays with the weekend and to analyse the contribution of a schoolbase physical exercise (PE) session to the total number of daily steps performed by children. The sample comprised 105 pre-school children, from 3 to 6 years old (4.48±0.69) from 5 kindergartens from Bragança. The PA evaluation was done through daily number of steps from New-Lifestyles NL-2000 pedometer. The mean number of steps taken by the children remained relatively constant during the week, decreasing only slightly on Friday. However, on Saturday and Sunday the decline was more pronounced. Significant differences were found between the number of steps on weekdays and weekend days (p<0.001), with higher levels of PA on weekdays. PA was higher (p<0.001) on the days with PE session than without PE session in kindergarten. Children of preschool age are more active during the weekdays than at the weekend. The implementation at school-based of PE session at pre-school level had a significant impact on daily PA levels of the children.info:eu-repo/semantics/publishedVersio

Exercise biomechanics for health: evaluating lifelong activities for well-being

Biomechanics is a multidisciplinary study of the mechanical laws and principles that govern human movement and the functioning of biological systems [1]. In the context of physical activity, exercise and physical fitness, biomechanics plays a crucial role in understanding the most efficient and effective ways to improve health and well-being. In addition, biomechanics aim to improve athletes’ performance as well as the movement efficiency of the whole population, leading to a better quality of life. To that end, concerns about optimal economy of movement, strength, power, stability, postural alignment, range of motion and athletic performance are some of the most important topics to address in the study of exercise biomechanics [2].info:eu-repo/semantics/publishedVersio

The effects of daily physical activity on functional fitness, isokinetic strength and body composition in elderly community-dwelling women

Physical inactivity has been classified as a public health problem. The excess fat with muscle loss along with the general decline of physical and functional capacity. The aim of this study was to evaluate the relative contribution of objectively estimated daily physical activity (PA) in functional fitness, isokinetic strength and body composition in community-dwelling elderly women. Sixty elderly female volunteered for this research, with 67.69 ± 5.30 years old. Daily PA was assessed using accelerometers for 7 days. The evaluation and quantification of body composition, total lean body mass, fat mass, total body fat mass and bone mineral density, were made with the DXA equipment. Body Mass Index (BMI) was also calculated. The functional fitness (FF) assessment was performed using Functional Fitness Test. The knee extensor and flexor isokinetic strength was evaluated in both lower limbs, using a dynamometer at two different angular velocities: 60°/sec. and 180°/sec. Body Composition, Bone Mineral Density (p = 0.014) and Fat Mass (p = 0.029) were statistically lowers in the 3rd tertile compared to the 2nd one. The knee flexion peak torque at 180°/sec on the dominant leg (p = 0.051) and non-dominant leg (p = 0.020) was statistically different between the less active group and the most active group. For the FF, no significant differences between groups were found. Our results suggest that daily PA seems to induce benefits on BMI and % Fat Mass as well as on isokinetic knee flexion strength of independent and community dwelling-resident’s older women.This study was developed in the Research Centre on Physical Activity Health and Leisure (CIAFEL) that is supported by Pest-OE/SAU/UI0617/2011info:eu-repo/semantics/publishedVersio

Effects of muscle strength, agility, and fear of falling on risk of falling in older adults

Falls are a major public health problem among older adults because they lead to premature mortality, loss of autonomy, and increased dependence on others. However, these associations have not been explored using procedures that analyze the sequential effects between risk factors of falling. The present study aimed to examine the effects of muscle strength, agility, and fear of falling on risk of falling using path analysis in community-dwelling older adults. In total, 49 elderly (female = 33, male = 16) participants aged between 65 and 76 years (M = 68.38 years; SD = 6.22) were included for analysis. Muscle strength, agility, fear of falling, and risk of falling were assessed using validated instruments for the older adult population. The proposed model shows that muscle strength was negatively associated with agility. Consequently, agility was negatively associated with fear of falling. The same trend appeared between fear of falling and risk of falling. The effect sizes were between small and medium for agility (R2 = 0.16), fear of falling, (R2 = 0.29), and risk of falling (R2 = 0.03). The main finding of the present study was that muscle strength was significantly correlated with agility, which, in turn, predicted fear of falling. Consequently, lower scores for fear of falling explained lower risk of falling in community-dwelling older adults. While muscle strength is a crucial component of physical fitness, only with adequate levels of agility can older adults possess the efficacy and ability to perform daily tasks.This research was funded by national funds from the Portuguese Foundation for Science and Technology, I.P. (grant number UIDB/04748/2020 and grant number UIDB/04045/2020).info:eu-repo/semantics/publishedVersio

Study of the association between postural misalignments in school students

Nowadays, postural misalignments prevalence in students is increasingly evident and its early detection is the best way to prevent complications in adulthood. It is also known that postural problems appear to have association between them. The aim of this study was to characterize and study the association between spine, scapular and pelvic girdles postural misalignments in 213 school students (124 males and 89 females), aged between 10 and 20 years, from Escola Básica e Secundária de Santa Maria (EBSSM). To understand the relation between postural misalignments we compare the head positioning with the shoulder girdle, the shoulder girdle with the dorsal spine and the lumbar spine with the pelvic girdle. The postural assessment was made by visual scan analysis in a symmetrograph based on photogrammetry and the Adams. We found high percentages of postural misalignments in all subjects. High prevalence was observed in the posterior view of the frontal plane in the head lateral flexion, shoulders vertical asymmetry, scoliosis and in the presence of gibbosity, whereas, in the right view of the sagittal plane forward head posture and protracted shoulders were observed. The lumbar scoliosis was more prevalent in subjects with iliac crest’s asymmetry (p < 0.001) and forward head posture was significantly related to the subjects with protracted shoulders (p = 0.010). The protracted shoulders were more prevalent in subjects with dorsal hyperkyphosis (p = 0.048) and lumbar hyperlordosis was related to the subjects with pelvic anteversion (p < 0.001). The students’ postural assessment showed a wide variety of postural misalignments. It also seems evident that there is a relationship between their occurrences. It should be highlighted the importance of postural assessment in physical education (PE) classes to determine postural misalignments among school students.This work is supported by the Douro Higher Institute of Educational Sciences and the Portuguese Foundation for Science and Technology, I.P. (project UIDB/04045/2021).info:eu-repo/semantics/publishedVersio