The influence of kineanthropometrical profile in deep-water tethered running

Aquatic jogging is a variant of head-out aquatic exercises characterised by the walking and/or running of a subject in aquatic environment. The main goal of this aquatic program is to promote an increase of physical fitness, specially the cardiorespiratory component

The influence of kineanthropometrical profile in deep-water tethered running

The purpose of this study was to identify the kineanthropometrical parameters that best predict the maximal horizontal propulsive force during deep-water tethered running. 21 young and healthy males with large experience in aquatic exercises (24.3+/-2.7 years old, 191.9+/-82.6 minutes physical activity per week) performed 3 repetitions of maximal deep-water running for 10-s, using a flotation vest (Golfinho, H-906, Coimbra, Portugal). The subjects were connected to a strain gauge (Globus, Ergo Meter, Codigné, Italy) by a cable of steel with reduced elastic properties. The other end of the cable was fasted to a rubber band and this to a swimming starting block. Dynamometrical data was exported and processed with Matlab v. 6.0. It was evaluated the maximal propulsive force (Fx-max) and computed the maximal horizontal propulsive force through a trigonometric correction, as suggested by Taylor et al. (2003). Body mass (SECA, 884, Hamburg, Germany), height (SECA, 242, Hamburg, Germany), body mass index (BMI) and fat mass (BIA 101, RJL Systems, Florence, Italy) were also measured. Surface area (SA) was calculated according to the procedure of Du Bois and Du Bois (Shuter and Aslani, 2000). The forearms (Globus, Ergo Meter, Codigné, Italy) and hands (TSD 121C, Biopac Systems, California, USA) maximal isometric forces were also measured. Intra-cyclic variation of the Fx-max presented a tetra-modal profile. Computing a stepby- step regression equation, for prediction of the Fx-max, the kineanthropometrical variables that entered the model were the forearms maximal isometric force, the BMI, the body mass and the SA (r^2=0.57, p=0.01). The purpose of the study was achieved. Evidences revealed that some kineanthropometrical parameters related to buoyancy force (e.g., fat mass), to drag force (e.g., SA and height), to weight force (e.g., body mass) and to propulsive force (e.g., segmental forces) predicted the Fx-max. This means that, besides physical fitness and technical level, often described in the literature, kineanthropometrical characteristics of the runner also affect significantly his performance during a training session. The main conclusion is that tethered running is significantly associated to kineanthropometrical profile of the runner. So, instructors should pay attention to kineanthropometrical characteristics of runners and how it affects their performance

Prevalence of postural changes in youth soccer players: a descriptive study

Introdução: A prática desportiva de competição pode integrar o conjunto dos fatores de risco associados às alterações posturais em crianças e jovens. Objetivo: Pretendeu-se estimar a prevalência de assimetrias posturais em crianças e jovens praticantes de futebol de competição. Métodos: Estudo seccional observacional. A amostra foi composta por 47 praticantes de futebol do sexo masculino entre 9 e 16 anos (13,02 ± 2,51), pertencentes aos escalões de juniores B, C, D e E. Recorreu-se a procedimentos cinemétricos e técnicas de fotogrametria com recurso do programa computacional SAPo para averiguar a prevalência de alterações posturais. Para analisar as diferenças entre a prevalência de assimetrias entre os escalões utilizou-se o teste de Kruskall-Wallis e de Dunn. O nível de confiança foi de 95%. Resultados: Verificaram-se assimetrias posturais no alinhamento vertical dos acrómios (72%), das linhas articulares do joelho (87%), nos pontos médios das patelas (89%), nas tuberosidades das tíbias (91%), maléolos laterais (87%) e mediais (77%). Na coluna vertebral, verificou-se a prevalência de escolioses, sobretudo torácicas (79%, T3-T7) e de prevalência mais baixa lombares (64%, L1-L5). Observou-se uma tendência para a diminuição dos desalinhamentos das tuberosidades das tíbias e dos maléolos laterais com a idade. Também foi verificado um aumento das escolioses e das assimetrias ao nível da linha média da perna. Conclusão: Houve diferenças significativas na prevalência de assimetrias posturais entre escalões em tuberosidades tibiais, maléolos laterais, linha média da perna e escolioses nas vertebras C7-L1 e L1-L5. As exigências próprias da modalidade de futebol podem estar associadas a um perfil postural do jovem futebolista.Competitive sport practice can be a potential risk factor for postural changes in children and young people. Objective: To estimate the prevalence of postural asymmetries in children and adolescents practicing competitive football. Methods: This was a sectional observational study. The sample consisted of 47 male soccer practitioners aged between 9 and 16 years (13.02 ± 2.51), belonging to the junior, B, C, D and E scalons. We used procedures and techniques of photogrammetry using SAPo software to assess the prevalence of postural changes. The Kruskall-Wallis and Dunn tests were used to analyze the differences on prevalence of asymmetries between the ranks. The confidence level was 95%. Results: Posterior asymmetries were observed in the vertical alignment of the acromion (72%), the knee joint lines (87%), the middle points of the patellae (89%), the tibial tuberosities (91%), the lateral (91%) and medial (77%) malleoles. In the vertebral column, the prevalence of scoliosis, mainly thoracic (79%, T3-T7) and lower lumbar prevalence (64%, L1-L5) was observed. Tibial tuberosities and lateral malleoli assimetries prevalence tends to reduce with age. In counterpart, scoliosis and leg medial line assimetries tends to increase with age. Conclusion: The prevalence of postural alterations ranged from tibial tuberosities, lateral malleoli, midline of the leg and scoliosis in vertebrae C7-L1 and L1-L5. The sports competition in youths can be a risk factor for postural changes in young players.info:eu-repo/semantics/publishedVersio

Changes in classical kinematics and non‐linear parameters after a maximal 100‐m front‐crawl bout

In a linear system there is proportionality between input and output. Under this framework it is expected that the amount of change in sports performance must be proportional to variations in the inputs.info:eu-repo/semantics/publishedVersio

Variation of linear and nonlinear parameters in the swim strokes according to the level of expertise

The aim was to examine the variation of linear and nonlinear proprieties of the behavior in participants with different levels of swimming expertise among the four swim strokes. Seventy-five swimmers were split into three groups (highly qualified experts, experts and nonexperts) and performed a maximal 25m trial for each of the four competitive swim strokes. A speed-meter cable was attached to the swimmer's hip to measure hip speed; from which speed fluctuation (dv), approximate entropy (ApEn) and fractal dimension (D) variables were derived. Although simple main effects of expertise and swim stroke were obtained for dv and D, no significant interaction of expertise and stroke were found except in ApEn. The ApEn and D were prone to decrease with increasing expertise. As a conclusion, swimming does exhibit nonlinear properties but its magnitude differs according to the swim stroke and level of expertise of the performer.info:eu-repo/semantics/publishedVersio

Influência da adubação verde e diferentes adubos orgânicos na produção de fitomassa aérea de atroveran.

Resumo: Este trabalho teve por objetivo verificar o efeito de diferentes adubos orgânicos em associação ou não com adubo verde na produção de folhas de Ocimum selloi Benth., planta nativa do Brasil. O experimento foi conduzido na área experimental da Embrapa Meio Ambiente (CNPMA), localizado no município de Jaguariúna, em duas áreas distintas, sendo uma delas submetidas anteriormente ao plantio e incorporação de adubo verde (Crotalaria juncea). Os tratamentos utilizados foram: T1 - testemunha (solo sem adubação), T2 - cama de aviário (5 kg/m2), T3 - hidrolisado de peixe (produto comercial Fishfértil - 5 mL/m2) e T4 - composto orgânico (4 kg/m2). A colheita foi realizada 180 dias após o plantio, em Janeiro de 2011, sendo colhidas as plantas úteis (quatro plantas por parcela). Avaliou-se o rendimento de fitomassa fresca e seca. O delineamento experimental adotado foi o esquema fatorial 2x4, com quatro repetições (blocos). As médias obtidas foram submetidas à análise de variância seguida de teste de médias (Tukey). Com base nos resultados obtidos, pode-se concluir que a cama de aviário apresentou resultados mais satisfatórios quanto à produção de folhas de Ocimum selloi quando comparados aos demais tratamentos orgânicos, não observando-se incremento nos resultados pela associação com o adubo verde Crotalaria juncea. Abstract: Influence of green manure and different organic manure on production of aereal phytomass of Ocimum selloi. The aim of this work was to avail the effect of different manures in association or nor with green manure on yield of leaves of Ocimum selloi Benth. The assay was accomplished on experimental area of Embrapa Environmental (Jaguariúna district), at two different spaces (with or without green manure Crotalaria juncea). The treatments used were: T1 - witness (no manure), T2 - chicken manure (5 kg/m2), T3 - commercial product Fishfértil - 5 mL/m2) and T4 - composting (4 kg/m2). The cut was realized on 180 days after the planting (January - 2011), and were collected four plants/ plot. The yield of dried and fresh Ocimum selloi phytomass was availed. The experimental design was factorial scheme (2x4), with four repetitions. The treatment with chicken manure showed best results on treatments, but did not was influence by using Crotalaria juncea

Can concurrent teaching promote equal biomechanical adaptations at front crawl and backstroke swimming?

The biomechanical adaptations in front crawl and backstroke swimming, as influenced by the implementation of a concurrent teaching programme were analysed. Methods: Sixteen participants (19.75 ± 1.13 years) underwent a 30 weeks intervention characterized by an increasing complexity to accomplish motor skills in the following order: (i) lower limbs propulsion; (ii) lower limbs propulsion synchronized with breathing cycle; (iii) lower limbs propulsion synchronized with one upper limb action; (iv) lower limbs propulsion synchronized with both breathing cycle and one upper limb action; (v) full swimming stroke; (vi) motor trajectory of the arms stroke. Performance and biomechanics were measured at front crawl and backstroke during three time points throughout the programme. There were improvements in performance over time at front crawl (21.49 s to 19.99 s, p < 0.01) and backstroke (27.15 s to 24.60 s, p = 0.01). Significant improvements were found for velocity at front crawl (1.13 m/s to 1.22 m/s, p < 0.01) and backstroke (0.92 m/s to 1.00 m/s, p < 0.01). Stroke frequency increased at backstroke (0.64 to 0.73 Hz, p = 0.01), while the intra-cyclic variation of the velocity decreased at front crawl (0.13 to 0.12%, p = 0.02). There was also a moderate-high inter-subject variability in response to the programme. These findings prove that a programme of 30 weeks teaching concurrently front crawl and backstroke is effective to promote similar biomechanical adaptations in low-tier swimmers. However, each subject shows an individual response to better adapt the biomechanical actions and to reach a higher level of expertise.info:eu-repo/semantics/publishedVersio

Lower limbs strength levels by lateral preference in under 17 soccer players

A força dos músculos ântero-posteriores dos membros inferiores direitos nos esquerdinos e ambidestros deve ser tanto quanto possível, desenvolvida de forma equilateral.Antero-posterior muscles strength in right limbs should be developed in a similar way with left ones, intending to reduces differences as much as possible.info:eu-repo/semantics/publishedVersio

Stability of pace and turn parameters of elite long-distance swimmers

This study aimed to assess the stability of the performance, pace and turn parameters of elite long-distance male swimmers during an 800 m freestyle race. The sample was composed by 38 male swimmers, participating in the 800 m event at the 2016 LEN European Aquatic Championships (long course meter). The performance, and a set of pace and turn parameters were analyzed. A customized software was used to perform each race analysis. Swimmers spent 64.05 ± 0.50% and 35.95 ± 0.49% of the final race time in the clean swim and turns, respectively. In the pace parameters, the clean swim was the only one that did not differ between the first and second half of the race (1.63 ± 0.05 vs 1.62 ± 0.05 m·s−1), and in the turn parameters, the water break distance was also similar (5.13 ± 1.17 vs 5.06 ± 0.98 m). A significant and moderate-strong variation was verified for the performance (total race lap effect: p < 0.001, η2 = 0.62), and a significant and moderate variation for the pace parameters (total race: p < 0.001, 0.15 ≤ η2 ≤ 0.33), and for the turn parameters (total race: p < 0.01, 0.15 ≤ η2 ≤ 0.33). Present data (pace and turn variation) shows that elite long-distance male swimmers do not maintain a similar pattern during an 800 m freestyle race. Future research is need to understand if this lack of pace and turn stability is the best way to enhance the performance, or if swimmers should be advised to control their pace and turn. Nevertheless, coaches are advised to help swimmers with feedback about their pace (i.e., controlling the intermediate 30 m) and turn performances (i.e., controlling the 5 m in and 15 m out), leading to a positive effect in their final race time.To LEN (Ligue Européenne de Natation) and Spiideo AB for providing the videos. This project was supported by the National Funds through FCT – Portuguese Foundation for Science and Technology ( UID/DTP/04045/2013 ) – and the European Fund for regional development ( FEDER ) allocated by European Union through the COMPETE 2020 Programme (POCI-01-0145-FEDER-006969). We would like also to thank the support of the University of Beira Interior and Santander Universities (Bolsa BIPD/ICIFCSH-Santander Universidades-UBI/2017).info:eu-repo/semantics/publishedVersio