Perfil da força muscular isométrica em atletas de rugby em cadeira de rodas / Profile of isometric muscle strength in athletes of wheelchair rugby

Objetivo: Analisar os níveis de força muscular em atletas de rugby em cadeira de rodas (RCR). Método: A amostra foi composta por 10 atletas (homens) com lesão da medula espinhal em nível cervical (tetraplegia) com média de idade de 31,1±5,06 anos. Os atletas foram recrutados na equipe de RCR do Projeto de Atividade Motora e Esporte Adaptado da Universidade Estadual de Campinas (ADEACAMP/UNICAMP). Resultados: Para analisar os níveis de força muscular isométrica (flexão e extensão dos ombros e cotovelos) foi utilizado dinamômetro isométrico, enquanto ultrassom foi usado para avaliação da espessura muscular (flexores e extensores do cotovelo, ambos os lados), utilizando 7,3 MHz da sonda linear-matriz. Correlação ponto-bisserial foi utilizada para verificar a associação entre os níveis de força de acordo com a posição de jogo; enquanto a correlação de Spearman verificou a associação entre os níveis de força entre membros dominantes e não dominantes, além da relação músculo agonista versus antagonista. Ainda, o teste Mann Whitney U foi utilizado para comparar os jogadores titulares e reservas quanto à força e espessura muscular. Conclusão: Podemos concluir que quanto maior a classificação funcional, maiores são os valores de força voluntária isométrica máxima; e que a força isométrica tem correlação com o desempenho de atletas de RCR

Objective: The aim of this study was to analyze muscle strength levels in wheelchair rugby athletes. Methods: The sample was 10 athletes (men) with spinal cord injury at cervical level (tetraplegia) with mean age of 31.1 ± 5.06 years. The athletes were recruited in the rugby team in wheelchair of the Motor Activity and Adapted Sport Project of the University of Campinas (ADEACAMP/UNICAMP). Results: In order to analyze the isometric muscular strength levels (flexion/extension of the shoulders and elbows), dynamometer was used, while muscle thickness was verified by ultrasound (flexors and extensors of the elbow, both sides), using 7.3 MHz of the linear-array probe. Point bi-serial correlation was applied to verify associations of game position and strength; while Spearman's correlation verified associations of strength and dominant and nondominant sides, and the relationship of agonist versus antagonist muscles. Moreover, the Mann Whitney U test was used to compare first to second-string players regarding strength and muscle thickness. Conclusion: We concluded that the higher the functional classification, higher the values of maximum isometric voluntary strength; and that the isometric strength correlates with their rugby performances

Muscle Strength Cutoff Points for Functional Independence and Wheelchair Ability in Men With Spinal Cord Injury.

OBJECTIVE: Determine trunk and shoulder muscle strength cutoff points for functional independence and wheelchair skills, and verify the predictive capacity of relative and absolute peak torque in men with spinal cord injury (SCI). DESIGN: Cross-sectional study. SETTING: Rehabilitation hospital setting. PARTICIPANTS: Men (N=54) with SCI were recruited and stratified into high and low paraplegia groups. INTERVENTIONS: All participants performed maximum strength tests for shoulder abduction or adduction (isokinetic) and trunk flexion or extension (isometric) to determine relative and absolute peak torque cutoff points for the Spinal Cord Independence Measure version III (SCIM-III) and Adapted Manual Wheelchair Circuit (AMWC). MAIN OUTCOME MEASURES: The primary outcome measures were SCIM-III, AMWC-Brazil test, and strength variables (peak torques). Demographic characteristics obtained from participants' electronic medical records were the secondary outcomes used as predictor variables of functional independence. RESULTS: The best predictive model for SCIM-III (R=0.78, P≤.05) used the sum of trunk flexion and extension relative peak torque values to determine the cutoff points (1.42 N·m/kg for a score of 70). Relative shoulder abduction peak torque was used in the predictive models for AMWC outcomes: performance score (R=0.77, P≤.05, cutoff points of 0.97 N·m/kg for 300.0m) and 3-minute overground wheeling (R=0.72, P≤.05, cutoff points of 0.96 N·m/kg for 18.5s). CONCLUSIONS: Relative peak torque showed better predictive capacity compared to absolute peak torque. Cutoff points were established for relative muscle strength and could help health professionals set appropriate goals for individuals with SCI to achieve high functional independence and wheelchair ability.

Avaliação isocinética em atletas da seleção brasileira de futebol de 5 / Isokinetic evaluation of Brazilian 5-a-side team / Evaluación isocinética en los atletas de la selección Brasileña de fútbol de 5

INTRODUÇÃO: A força muscular (FM) dos membros inferiores é um dos principais componentes exigidos para as ações específicas durante a prática do futebol de 5 e, quando apresentam níveis insuficientes, desequilíbrios bilaterais elevados ou acentuada diferença na razão agonista/antagonista (RAA) são fatores que contribuem para o desenvolvimento de lesões musculoesqueléticas. OBJETIVO: A proposta deste estudo foi avaliar os níveis de torque máximo, a diferença bilateral na produção de força e a razão convencional das musculaturas flexoras e extensoras do joelho em diferentes velocidades de execução. MÉTODOS: Participaram do estudo 11 atletas deficientes visuais. Os atletas foram submetidos à avaliação antropométrica para determinação da composição corporal e submetidos à avaliação com dinamômetro isocinético para a mensuração dos níveis de desequilíbrio muscular e razão convencional. RESULTADOS: Nos movimentos concêntricos da musculatura flexora foram observadas diferenças significativas no pico de torque (PT) entre os membros dominante (MD) e não dominante (MND) na velocidade de 60°.s-1 e 180°.s-1, no pico de torque normalizado (PTN) a 60°.s-1 e na velocidade de 180°.s-1 para os músculos extensores. Na RAA, observou-se diferença significativa entre MD e MND, e níveis aceitáveis de RAA em ambas as pernas, de acordo com o proposto para o futebol convencional. CONCLUSÃO: Espera-se que os resultados do presente estudo possam contribuir para os processos de prevenção, treinamento e reabilitação de atleta de futebol de 5, como também, servirem como parâmetros para futuros estudos. .

INTRODUCTION: Muscle strength (MS) of the lower limbs is one of the main components required for specific actions during practice of 5-a-side football and when the levels are insufficient, elevated bilateral imbalances or marked difference in agonist/antagonist ratio (AAR) are factors that contribute to the development of musculoskeletal injuries. OBJECTIVE: The purpose of this study was to assess levels of peak torque, bilateral difference in force production and conventional ratio of flexor and extensor musculature of the knee in different speeds. METHODS: The study included 11 visually impaired athletes. The athletes underwent anthropometric measurements to determine body composition and underwent evaluation at the isokinetic dynamometer to measure the levels of muscle imbalance and conventional ratio. RESULTS: In concentric movements of the flexor muscles, significant differences were observed in peak torque (PT) between the dominant limb (DL) and non-dominant limb (NDL) at 60° .s-1 and 180°.s-1, the peak torque standardized (PTS) at 60°.s-1 and 180 °.s-1 to the extensor muscles. In AAR, there was significant difference between DL and NDL, and acceptable levels of AAR in both legs according to the proposed for conventional football. CONCLUSION: It is expected that the results of this study may contribute to the processes of prevention, training and rehabilitation in athletes of 5-a-side football, also, serve as parameters for future studies. .

INTRODUCCIÓN: La fuerza muscular (FM) de los miembros inferiores es uno de los principales componentes necesarios para acciones específicas durante la práctica de fútbol de 5 y, cuando presentan niveles insuficientes, los desequilibrios bilaterales elevados o acentuada diferencia en la razón agonista/antagonista (RAA), son factores que contribuyen para el desarrollo de lesiones musculoesqueléticas. OBJETIVO: En este sentido, la propuesta del estudio fue evaluar los niveles de torque máximo, diferencia bilateral en la producción de fuerza y razón convencional de las musculaturas flexoras y extensoras de la rodilla en diferentes velocidades de ejecución. MÉTODOS: Participaron en el estudio 11 atletas con discapacidad visual. Los atletas fueron sometidos a evaluación antropométrica para determinación de la composición corporal y sometidos a evaluación en el dinamómetro isocinético para medir los niveles de desequilibrio muscular y la razón convencional. RESULTADOS: En los movimientos concéntricos de la musculatura flexora, se observaron diferencias significativas en el pico de torque (PT) entre los miembros dominantes (MD) y no dominante (MND) en la velocidad de 60°.s-1 y 180°.s-1, en el pico de torque normalizado (PTN) a 60°.s-1 y 180°.s-1 para los músculos extensores. En la RAA se observó diferencia significativa entre MD y MND, y niveles aceptables de RAA en ambas piernas de acuerdo con lo propuesto para el fútbol convencional. CONCLUSIÓN: Se espera que los resultados del presente estudio puedan contribuir para los procesos de prevención, entrenamiento y rehabilitación de los atletas de fútbol de 5, así como también que sirvan como parámetros para futuros estudios. .

Beta-hydroxy-beta-methylbutyrate supplementation reduces tumor growth and tumor cell proliferation ex vivo and prevents cachexia in Walker 256 tumor-bearing rats by modifying nuclear factor-kappaB expression.

Cancer cachexia syndrome contributes to wasting and weight loss leading to inefficacy of anticancer therapy. In this study, the anticatabolic agent beta-hydroxy-beta-methylbutyrate (HMB) was supplemented to adult Walker 256 tumor-bearing rats during 8 weeks aiming to determine if tumor burden could be reduced. Male Wistar rats were randomly assigned to nontumor and tumor-bearing groups and fed regular chow or regular chow plus HMB supplemented (76 mg/kg body weight). Beta-hydroxy-beta-methylbutyrate supplementation induced a lower tumor weight and tumor cell proliferation ex vivo, totally prevented glycemia reduction, as well as blunted the increase in the serum lactate concentrations and also preserved glycogen stores in tumor-bearing rats. Reduction in tumor cell proliferation ex vivo was accompanied by increased nuclear factor-kappaB inhibitor-alpha content by more than 100%. In contrast, nuclear factor-kappaB p65 subunit content was suppressed by 17% with HMB supplementation. In conclusion, HMB supplementation, at a similar dose used in humans to increase muscle mass, caused antitumor and anticachectic effects, with tumor-cell nuclear factor-kappaB pathway participation, which might be a potential nutritional strategy in cancer therapy.