Triceps surae neuromechanical properties after achilles tendon surgical repair : from rehabilitation to training

As rupturas do tendão de Aquiles vêm aumentando com o aumento do interesse em práticas esportivas. O programa de reabilitação pós-operatório pode ser realizado com reabilitação tradicional com imobilização, ou acelerada com mobilização e descarga de peso precoce. A abordagem acelerada aumenta a amplitude de movimento (ADM) do tornozelo e aumenta a hipertrofia do músculo tríceps sural. Contudo, apesar da reabilitação acelerada ser mais indicada para uma recuperação rápida, os pacientes apresentam déficit na força muscular mesmo depois de mais de dez anos da cirurgia. Uma das estratégias para diminuir esses efeitos deletérios persistentes no longo prazo é a realização de treinamento excêntrico. Contudo, o exercício excêntrico pode trazer um risco de re-rupturas ou tendinopatia devido às altas cargas se estas não são aplicadas com uma intensidade apropriada. Dessa forma, o objetivo da presente tese de doutorado é identificar os efeitos dos diferentes programas de reabilitação descritos na literatura e verificar os efeitos do exercício excêntrico em pessoas que passaram pelo reparo cirúrgico do tendão de Aquiles. A tese foi dividida em quatro capítulos que correspondem a quatro artigos independentes com objetivos específicos. No capítulo 1, uma revisão sistemática com metanálise foi desenvolvida para comparar os efeitos da reabilitação tradicional com a reabilitação acelerada na força dos plantiflexores, na ADM do tornozelo, na capacidade funcional, na morfologia tendínea e muscular e no desempenho do teste de elevação do calcanhar após ruptura do tendão de Aquiles. Apesar do alto risco de viés encontrado nos estudos, quando os protocolos são comparados não foram encontradas diferenças a favor de nenhum programa para a força muscular. Entretanto, há um efeito em favor da reabilitação acelerada para diminuir déficits de força excêntrica e de ADM. Portanto, o protocolo acelerado, apesar de apresentar bons efeitos relacionados a ADM, não foi superior ao protocolo de imobilização no que se refere à força muscular dos plantiflexores. Esses 2resultados instigaram a realização de um estudo, com dados do nosso grupo de pesquisa, para tentar entender um pouco mais os efeitos da reabilitação acelerada nas propriedades neuromusculares desses pacientes. Neste segundo capítulo, a proposta foi comparar os efeitos de um protocolo de reabilitação tradicional de imobilização com um protocolo de reabilitação acelerada na ADM, na arquitetura do gastrocnêmio medial e no torque dos plantiflexores logo após a reabilitação (aos 3 meses), e após 6 meses e 30 meses da cirurgia de reconstrução tendínea. Neste estudo, encontramos que a reabilitação acelerada leva a maior ADM de plantiflexão do tornozelo (p=0.007; d=1.61), maior comprimento de fascículo (p=0.043; d=1.10) e maior espessura do músculo gastrocnêmio medial comparado ao grupo tradicional (tanto na perna saudável, p=0.036; d=1.01; quanto na com lesão, p=0.006; d=1.38). Entretanto, independente do protocolo de reabilitação, a perna com ruptura teve menor força de flexão plantar comparada com a perna sem lesão (p<0.001; d=1.46), mesmo após o longo prazo decorrente da cirurgia de reconstrução. Esses resultados indicaram a busca de uma solução para diminuir esses efeitos deletérios relacionados à força muscular. Escolhemos um programa de exercício excêntrico com o objetivo de aumentar a força muscular, o comprimento fascicular, a espessura muscular e remodelar a estrutura tendínea, a fim de tentar diminuir os déficits encontrados nesses pacientes, que parecem ser permanentes mesmo depois de mais de 2 anos da cirurgia. Para isso, no capítulo 3, verificamos o efeito de duas modalidades de treinamento excêntrico, convencional (na academia) e isocinético (no dinamômetro) durante 12 semanas, sobre a massa muscular do tríceps sural, a ativação muscular, o torque dos plantiflexores e a ADM em 28 pacientes que passaram por cirurgia de reconstrução do tendão. O treinamento convencional apresentou maior ativação excêntrica após 8 (p=0.02) e 12 semanas (p=0.001) de treinamento e maior ativação concêntrica após 12 semanas que o grupo isocinético na perna com lesão (p=0.04) e na perna sem lesão (p=0.01). O grupo isocinético apresentou maior massa muscular na perna com lesão no momento pré (p=0.001) e pós 4 (p=0.01) semanas de treinamento e maior massa muscular na perna sem lesão após 8 semanas (p=0.01). A perna sem lesão apresentou maior torque e ativação que a perna com lesão. O treinamento convencional foi capaz de diminuir assimetrias de espessura muscular (p=0.02) e o treinamento isocinético foi capaz de diminuir assimetrias de torque isométrico (p=0.009) após 8 semanas de treinamento. A ativação isométrica aumentou após 8 (p=0.001; d=5.44) semanas de treinamento excêntrico em ambos os grupos e pernas. O treinamento convencional aumentou a ativação concêntrica após 8 semanas na perna sem lesão (p<0.001; d=6.19) e após 12 semanas na perna com lesão (p=0.014; d=4.37) e aumentou a ativação excêntrica nas duas pernas após 8 semanas de treinamento (p=0.01; d=4.4). O treino convencional aumentou a massa muscular após 8 semanas de treinamento (p=0.002; d=5.2), enquanto o treinamento excêntrico aumentou após 12 semanas (p=0.002; d=2.56) na perna com lesão. Ambos os treinamentos aumentaram a amplitude de dorsiflexão após 8 semanas (p=0.03; d=0.83). O torque máximo de plantiflexão aumentou após 8 semanas [(isométrico, p=0.001; d=2.99); (concêntrico, p=0.001; d=2.49); e (excêntrico, p=0.001; d=2.24)] independente da modalidade de treinamento. Tendo em vista os efeitos positivos do treinamento excêntrico nas propriedades neuromusculares desses pacientes, e a possível complementariedade entre adaptações neuromusculares e tendíneas, no capítulo 4 verificamos os efeitos do treinamento excêntrico no comprimento total e livre do tendão, na área de secção transversa e na ecogeneicidade do tendão em 10 regiões diferentes do tendão. O tendão com ruptura apresentou maior área de secção transversa, menor ecogeneicidade, maior comprimento total e livre que o tendão saudável. Além disso, o tendão lesado apresentou diferentes áreas e ecogeneicidades ao longo de seu comprimento, principalmente no momento pré-treinamento. Essas diferenças entre as áreas diminuíram ao longo do treinamento, indicando uma melhora da estrutura tendínea com o treinamento de força. O treinamento convencional foi capaz de aumentar em 18% a área de secção transversa do tendão com ruptura na região de 5cm da inserção osteotendínea após 8 semanas de treinamento e aumentar o comprimento do tendão na perna sem lesão após 4 semanas, entretanto não foi capaz de causar mudanças na ecogeneicidade do tendão (p= 0.28). Os treinamentos excêntricos (em dinamômetro isocinético) e o convencional (em academias) são igualmente benéficos para pacientes que romperam o tendão de Aquiles, podendo ser utilizados indistintamente na reabilitação após longos períodos da cirurgia de reconstrução tendínea.Achilles tendon ruptures have been increasing with increasing interest in sports. Two different Achilles tendon rehabilitation programs have been used in clinical practice: a traditional rehabilitation, in which ankle immobilization of up to 6 weeks occurs; or an early rehabilitation, with early mobilization and early weight-bearing. The accelerated protocol increases the ankle joint range of motion (ROM) and hypertrophies the triceps sural muscle. However, although early rehabilitation is more suitable for fast recovery, patients have muscle strength deficits even after more than ten years post-surgery. One of the strategies to reduce these persistent harmful long-term effects is to perform eccentric training. However, there is a risk of re-rupture or tendinopathy due to the eccentric exercise’s high loads if they are not applied at the appropriate intensity. Therefore, the purpose of this doctoral thesis is to identify the effects of different rehabilitation programs described in the literature and verify the impacts of eccentric exercise on patients who have undergone Achilles tendon surgical repair. This thesis was divided into four chapters that correspond to four independent articles with specific goals. In chapter 1, a systematic review with meta-analysis was developed to compare traditional rehabilitation versus early rehabilitation effects on plantarflexion strength, ankle ROM, functional capacity, tendon and muscle morphology, and on the heel raise test after Achilles tendon rupture. Despite the high risk of bias found in the studies, when the protocols are compared, no improvements in muscle force were observed in favour of any program. However, there is an effect in favor of accelerated rehabilitation to reduce eccentric strength and ROM deficits. Thus, despite presenting sound effects related to ROM, early rehabilitation is not superior to the immobilization protocol regarding the plantar flexors’ muscle strength. These results instigated a study, with data from our research group, to understand a little better, the early rehabilitation effects at the neuromuscular properties of these patients. In this second chapter, the proposal was to compare the effects of a traditional immobilization protocol with an accelerated one in the ankle joint ROM, in the medial gastrocnemius architecture and the plantar flexor torque shortly after the rehabilitation program (at three months), and at six and 30 months post-surgery. The early rehabilitation led to greater ROM (p=0.007; d=1.61), greater fascicle length (p=0.043; d=1.10), and greater muscle thickness than the traditional program compared to the traditional group (both at the healthy limb, p=0.036; d=1.01; and at the injury limb, p=0.006; d=1.38). However, regardless of the rehabilitation protocol, the ruptured leg had less plantarflexion strength (p<0.001; d=1.46) than the healthy limb even after the long period after the tendon surgical reconstruction. These results motivated the search for a solution to reduce these deleterious effects related to muscle strength. We chose an eccentric training program aimed at increasing muscle strength, fascicle length, muscle thickness and remodeling the tendinous structure, to reduce the deficits found in these patients, which seems to be permanent even more than two years of the surgery. To achieve this goal, in chapter 3 we verified the effect of two types of eccentric training: conventional (in the gym) and isokinetic (in the dynamometer) during 12 weeks, on the triceps sural muscle mass, muscle activation, plantar flexor torque, and ankle ROM in 28 patients who had undergone tendon reconstructive surgery. The conventional training determined higher eccentric activation after 8 (p=0.02) and 12 (p=0.001) training weeks, and higher concentric activation after 12 weeks compared to the isokinetic at the injured leg (p=0.04) and the healthy leg (p=0.01). The isokinetic group showed higher muscle mass at the injured leg at the pre (p=0.001) and post-4 (p=0.01) weeks of training, and higher muscle mass at the healthy leg post-8 training weeks (p=0.01). The healthy leg showed higher torque and muscle activation compared to the injured leg. Conventional training was able to reduce muscle thickness asymmetries (p=0.02), and the isokinetic training reduced isometric torque asymmetries (p=0.009) post-8 training weeks. Isometric activation increased after 8 (p=0.001; d=5.44) weeks of eccentric training in both groups and legs. Conventional training increased concentric activation after 8 weeks in the uninjured leg (p<0.001; d=6.19) and after 12 weeks in the injured leg (p=0.014; d=4.37) and increased eccentric activation in both legs after 8 training weeks (p=0.01; d=4.4). Conventional training increased muscle mass after 8 weeks of training (p=0.002; d=5.2), while eccentric training increased after 12 weeks (p=0.002; d=2.56) in the injured leg. Both training sessions increased the dorsiflexion ROM after 8 weeks (p=0.03; d=0.83). Plantarflexion torque increased after 8 weeks [(isometric, p=0.001; d=2.99); (concentric, p=0.001; d=2.49); and (eccentric, p= 0.001; d= 2.24)], regardless of the modality of training. Due to the positive effects of eccentric training at the neuromuscular properties of these patients, and to the possible complementarity between neuromuscular and tendinous adaptations, in chapter 4, we verified the eccentric training effects on total and free tendon length, tendon cross-sectional area and echo intensity of 10 different tendon areas. The injured tendon showed a higher cross-sectional area, smaller echo intensity, longer total and free tendon length compared to the healthy tendon. In addition, the injured tendon presented different echo intensity areas along its length, mainly at the pre-training moment. These between-areas differences decreased throughout the training program, indicating an improvement in tendon structure with strength training. Conventional training was able to increase the cross-sectional area of the injured tendon after 8 weeks by 18% in the region of 5 cm of the osteotendinous insertion and to increase tendon length in the uninjured tendon after 4 weeks, however it was not able to change tendon echogenicity (p = 0.28).The eccentric training programs (conventional and isokinetic) equally benefit for patients that ruptured the Achilles tendon and can be used indistinctly in tendon rehabilitation even after long periods after the tendon surgical reconstruction

A representação das mulheres de carreira no cinema: uma análise sob a ótica das metáforas de desigualdade de gênero

As obras cinematográficas são consideradas eficientes para avaliar a sociedade e os ambientes de trabalho, pois refletem a maneira como a sociedade, de modo geral, pensa, age e se comporta sobre determinados assuntos. Diante do papel do cinema de reproduzir e produzir elementos sociais e individuais que envolvem a vida privada e profissional de mulheres que ambicionam ter sucesso nas suas carreiras, o presente artigo possui como objetivo analisar como os filmes retratam os desafios que as mulheres enfrentam para avançar em suas carreiras através das lentes das metáforas da desigualdade de gênero. Os filmes foram acessados por meio do site IMDb (Internet Movie Database), usando os descritores: women, business, career e manager. Considerados filmes produzidos de 1981 a 2019, obteve-se 205 peças cinematográficas.Aplicados os critérios de inclusão e exclusão, restaram 39 filmes para análise. Desse modo, a maneira como as mulheres de negócios são representadas pelo cinema é discutida por meio das metáforas: Teto de Vidro; Penhasco de Vidro; Fenômeno Abelha Rainha; Parede Materna; Segundo Turno; Labirinto; e Tokenismo. A construção das personagens, segundo as obras visitadas nesse artigo, evidenciou singularidades na abordagem na construção das protagonistas. Todos os filmes analisados nessa pesquisa apresentaram em alguma cena, diálogo ou modo como a personagem principal é descrita dentro da narrativa pelo menos uma das metáforas abordadas

AVALIAÇÃO ELETROMIOGRÁFICA DOS MÚSCULOS DAS COSTAS NO CICLISMO: UM ESTUDO DE CASO

Here we quantified the electric neuromuscular activity of selected back muscles of a trained mountain bike cyclist without history of low back pain. For data collection, cyclist’ own bicycle was attached to a cycle simulator. The cyclist cycled at workload set between 70% and 80% of peak power output until exhaustion. Electromyography data was analyzed considering the root mean square values computed to represent the overall magnitude of activation. There was a general increase in the muscle activation for all the muscles analyzed. This behavior was remarked for trapezius descendens (2.4%) and iliocostalis (31.77%) in the non-preferred body side, whereas the longissimus increased activation (11.33%) in the preferred side. The increase in muscle activation without report of low back pain suggests that effects of fatigue were observed. The protocol was useful to elicit fatigue in back muscles and can serve to investigate muscular imbalances usually associated with low back pain and hip weakness. Descriptors: Back Pain; Cycling; Fatigue; Exercise; Spine; Muscle Activation. Neste estudo quantificamos a atividade elétrica neuromuscular de músculos das costas de um ciclista treinado sem história de dor lombar. A sua bicicleta foi anexada a um simulador de ciclismo. Ele pedalou em intensidade entre 70% e 80% de seu pico de potência, até exaustão. Dados eletromiográficos foram analisados considerando o valor médio dos quadrados para representar a magnitude da ativação muscular. Houve um aumento da ativação muscular para todos os músculos. Trapézio descendente (2,4%) e iliocostal (31,77%) do lado não-preferido tiveram aumento da atividade muscular, já o longuíssimo do tórax (11,33%) teve aumento no lado preferido. O aumento da ativação muscular sem ocorrência de dor lombar sugere um efeito de fadiga. O protocolo foi útil para induzir fadiga de músculos lombares e pode ser útil para investigar desequilíbrios musculares frequentemente associados à dor lombar e fraqueza de quadril. Descritores: Dor Lombar; Ciclismo; Fadiga; Exercício; Coluna; Ativação Muscular.

Proximal, local, and distal muscle morphology in women with patellofemoral pain

Objective: The objective of this study was to compare proximal, local, and distal muscle morphology in women with and without patellofemoral pain (PFP). Materials and Methods: Proximal, local, and distal muscle thicknesses (MTs) were obtained with B-mode sonography in healthy (control group [CG], n = 20) and PFP (PFP group, n = 20) women. In addition, muscle mass was measured by the sum of the synergistic MTs. Data were analyzed by independent t-test, Mann-Whitney U test, and effect size. Results: PFP women had smaller gluteus medius (P = .02, d = 0.7), vastus medialis (P < .01, d = 1.0), and flexor digitorum brevis (P < .01, d = 1.0) MT and greater gastrocnemius medialis (P = .04, d = 0.6) MT than CG. Quadriceps muscle mass (P = .01, d = 0.8) and foot muscle mass (P = .008, d = 0.9) were smaller, while plantar flexor muscle mass was greater in the PFP group than in CG (P = .01, d = 0.8). Conclusion: PFP women have proximal, local, and distal MT alterations in comparison with CG, which may explain possible changes in muscle strength and functionality

Antinociceptive and Anti-Inflammatory Activity from Algae of the Genus Caulerpa

Marine natural products have been the focus of discovery for new products of chemical and pharmacological interest. The aim of this study was to evaluate the antinociceptive activity of the methanolic (ME), acetate (AE), hexanic (HE) and chloroform (CE) extracts obtained from Caulerpa mexicana, and ME, CE and HE obtained from Caulerpa sertularioides. These marine algae are found all over the world, mainly in tropical regions. Models such as the writhing test, the hot plate test and formalin-induced nociception test were used to evaluate antinociceptive activity in laboratory mice. In the writhing test, all the extracts were administered orally at a concentration of 100 mg/kg, and induced high peripheral antinociceptive activity, with a reduction in the nociception induced by acetic acid above 65%. In the hot plate test, treatment with extracts from C. sertularioides (100 mg/kg, p.o.) did not significantly increase the latency of response, although the ME, AE and HE from C. mexicana showed activity in this model. This result suggests that these extracts exhibit antinociceptive activity. In the formalin test, it was observed that ME, AE and HE obtained from C. mexicana reduced the effects of formalin in both phases. On the other hand only CE from C. sertularioides induced significant inhibition of the nociceptive response in the first phase. To better assess the potential anti-inflammatory activity of the extracts, the carrageenan-induced peritonitis test was used to test Caulerpa spp. extracts on cell migration into the peritoneal cavity. In this assay, all extracts evaluated were able to significantly inhibit leukocyte migration into the peritoneal cavity in comparison with carrageenan. These data demonstrate that extracts from Caulerpa species elicit pronounced antinociceptive and anti-inflamatory activity against several nociception models. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for the antinociceptive action and also to identify the active principles present in the Caulerpa species

Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

<p>Abstract</p> <p>Background</p> <p>Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from <it>Canavalia gladiata </it>seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins; a site where a non-protein amino-acid, α-aminobutyric acid (Abu), is bound.</p> <p>Results</p> <p>The overall structure of native CGL and complexed with α-methyl-mannoside and Abu have been refined at 2.3 Å and 2.31 Å resolution, respectively. Analysis of the electron density maps of the CGL structure shows clearly the presence of Abu, which was confirmed by mass spectrometry.</p> <p>Conclusion</p> <p>The presence of Abu in a plant lectin structure strongly indicates the ability of lectins on carrying secondary metabolites. Comparison of the amino acids composing the site with other legume lectins revealed that this site is conserved, providing an evidence of the biological relevance of this site. This new action of lectins strengthens their role in defense mechanisms in plants.</p

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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