Effects of volume training on strength and endurance of back muscles: a randomized controlled trial

CONTEXT: Strength/resistance training volume has historically been supported in the American College of Sports Medicine recommendations. However, for the back muscles, exercise prescription related to the number of sets, such as single vs. multiple, is not well established in the literature. OBJECTIVE: The purpose of this study was to compare the effects of two training volumes on strength and endurance of back extensor muscles in untrained young participants, with regard to a repeated measures design. DESIGN: Randomized controlled trial. SETTING: Laboratory of functional evaluation and human motor performance. PARTICIPANTS: Forty-four untrained young participants (mean age = 21 yrs) were randomized into three groups: single set (SSG, n = 14), multiple sets (MSG, n = 15), and untrained control (CG, n = 15). INTERVENTION: The SSG and MSG underwent a 10-wk progressive resistance training program (2 days·week-1) using a 45° Roman chair. MAIN OUTCOME MEASURES: Back maximal strength (dynamometer) and isometric and dynamic endurance (time-limit, trunk extension-flexion cycles, and electromyography muscle fatigue estimates). RESULTS: The results showed differences between the MSG and control group for isometric endurance time (mean 19.8 seconds, 95% CI 44.1 to 4.8), but without time intervention significance. Significant improvement after training (P 0.05) difference in either strength or electromyography estimates after training. CONCLUSIONS: Both multiple and single volume training were efficient in promoting better back endurance during dynamic performance based on mechanical variables (time and number of repetitions)

Analysis of pain, functional capacity, muscular strength and balance in young women with Patellofemoral Pain Syndrome

Introduction : Patellofemoral Pain Syndrome (PFPS) is associated with anterior knee pain, changes in functional capacity, balance and muscle strength disorders. Objective : To quantify pain, functional capacity, strength in quadriceps (Q), gluteus medium (GM), hip external rotator (ER) muscles and balance in sedentary women with PFPS. Methods : Twenty sedentary women, aged 18 to 25 years, were divided into two groups: PFPS (N=10) and control group (N=10). All the volunteers answered the items of the Visual Analogue Scale (VAS), the Lysholm Knee Score Scale, the Anterior Knee Pain Scale (AKPS), and the Lower Extremity Functional Scale (LEFS). The participants performed the following tests: maximal voluntary isometric contraction measured by dynamometry; postural balance using the Star Excursion Balance Test (SEBT) and a force platform. Statistical analyses were performed using the Shapiro Wilk test, the Mann Whitney U test and Spearman’s correlation coefficient. Data were submitted to SPSS 20 software. Results : The PFPS group presented greater pain, balance impairment and higher average velocity of oscillation; however, no differences were observed in Q, GM and RE muscle strength and in balance analyzed by SEBT. Conclusion : Women with PFPS exhibited greater pain, worse functional capacity and body balance. Moderate correlation between both balance tests suggests the use of SEBT when the force platform is not available, which could facilitate and highlight the importance of clinical diagnosis with regard to postural balance. Introdução : A Síndrome da Dor Femoropatelar (SDFP) está relacionada à dor anterior do joelho, alteração de funcionalidade, déficits de equilíbrio e força muscular. Objetivo : Quantificar a dor, funcionalidade, força muscular do quadríceps (Q), glúteo médio (GM), rotadores externos de quadril (RE) e o equilíbrio em mulheres com SDFP. Métodos : Avaliou-se 20 voluntárias, sedentárias, entre 18 e 25 anos; divididas em grupo SDFP (N=10) e controle (N=10). Todas responderam a Escala Visual Analógica de Dor, Lysholm Knee Score Scale, Anterior Knee Pain Scale e Lower Extremity Functional Scale, realizaram a contração isométrica voluntária máxima dos músculos Q, GM e RE por meio de dinamometria e análise do equilíbrio postural pelo Star Excursion Balance Test (SEBT) e plataforma de força. Para análise estatística utilizou-se os testes Shapiro Wilk, Mann Whitney e Correlação de Spearmann, pelo SPSS® 20. Resultados : O grupo SDFP apresentou maior dor, incapacidade e velocidade média de oscilação do centro de pressão, entretanto não foram observadas diferenças para a força muscular de Q, GM e RE e equilíbrio analisado pelo SEBT. Estabeleceu-se correlação moderada entre SEBT e Centro de Oscilação de Pressão (COP) unipodal. Conclusão : Mulheres com SDFP apresentam maior dor, pior funcionalidade e alterações no equilíbrio corporal. A correlação moderada entre SEBT e o COP-unipodal aponta a possibilidade de uso deste teste funcional quando a plataforma de força não é acessível, o que facilita e destaca a importância do diagnóstico clínico do equilíbrio postural

Comportamento do consumidor em relação a produtos sustentáveis: uma revisão sistemática de literatura

This paper aims to conduct a systematic review of the literature on consumer behavior about sustainable products, in order to identify the factors that interfere in consumer behavior, as well as define sustainability attributes and the perception of the consumer about sustainability. More than 4600 texts were identified from a review, conducted in 22 academic and practitioners’ bases. Based on inclusion and exclusion criteria, 219 papers were selected and 95 of these were entirely analyzed. As a result, we identified eleven factors of influence on sustainability practices in the consumer behavior of sustainable products (environment, age, educational level, economic class, gender, conscience, self-image concern, emotion, legislation, access to information, trust and habit) and seven about consumer attributes and perception about sustainability (eco-friendly, origin assurance, consumer health, fair trade, animal testing, recyclables, and natural ingredients).Este artigo tem por objetivo realizar uma revisão sistemática de literatura sobre o comportamento do consumidor em relação aos produtos sustentáveis, a fim de identificar os fatores que interferem no comportamento, bem como definir os atributos e a percepção do consumidor frente ao tema sustentabilidade. Identificou-se mais de 4600 textos a partir da revisão, conduzida em 22 bases acadêmicas e practitioners. A partir dos critérios de inclusão e exclusão, 219 artigos foram selecionados e, desses, 95 foram totalmente analisados. Como resultado, foram identificados onze fatores de influência nas práticas de sustentabilidade no comportamento do consumidor de produtos sustentáveis (ambiente, idade, nível educacional, classe econômica, gênero, consciência, preocupação com a própria imagem, emoção, acesso à informação, confiança e hábito) e sete em relação aos atributos e percepção do consumidor acerca de sustentabilidade (eco-friendly, garantia de origem, saúde do consumidor, fair trade, teste em animais, recicláveis e ingredientes naturais)

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe