Influence of infrared camera model and evaluator reproducibility in the assessment of skin temperature responses to physical exercise.

Infrared thermography (IRT) has been gaining in popularity in clinical and scientific research due to the increasing availability of affordable infrared cameras. This study aims to determine the similarity of measurement performance between three models of IRT camera during assessment of skin temperature before and after physical exercise. Three models of FLIR thermographic cameras (E60bx, Flir-One Pro LT, and C2) were tested. Thermal images were taken of the foot sole, anterior leg, and anterior thigh from 12 well-trained men, before and after a 30-min run on a treadmill. Image files were blinded and processed by three evaluators to extract the mean, maximum, and standard deviation of skin temperature of the region of interest. Time for data processing and rate of perceived effort was also recorded. Data processing was slower on the E60bx (CI95% E60 vs C2 [0.2, 2.6 min], p = 0.02 and ES = 0.6); vs. Flir-One [0.0, 3.4 min], p = 0.03 and ES = 0.6) and was associated with lower effort perception (E60 3.0 ± 0.1 vs. Flir-One 5.6 ± 0.2 vs C2 7.0 ± 0.2 points; p < 0.001 and ES > 0.8). The C2 and Flir-One cameras underestimated the temperature compared with the E60. In general, measuring mean temperature provided higher camera and examiner intra-class correlations than maximum and standard deviation, especially before exercise. Moreover, post exercise mean skin temperatures provided the most consistent values across cameras and evaluators. We recommend the use of mean temperature and caution when using more than one camera model in a study.

Effects of changing speed on knee and ankle joint load during walking and running.

Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s(-1) ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.

Muscle activity and pedal force profile of triathletes during cycling to exhaustion.

The purpose of this study was to analyze pedaling cadence, pedal forces, and muscle activation of triathletes during cycling to exhaustion. Fourteen triathletes were assessed at the power output level relative to their maximal oxygen uptake (355 +/- 23 W). Cadence, pedal forces, and muscle activation were analyzed during start, middle, and end test stages. Normal and tangential forces increased from the start to the end of the test (-288 +/- 33 to -352 +/- 42 N and -79 +/- 45 to -124 +/- 68 N, respectively) accompanied by a decrease in cadence (96 +/- 5 to 86 +/- 6 rpm). Muscle activation increased from the start to the middle and the end in the gluteus maximus (27 +/- 5.5% and 76 +/- 9.3%) and in the vastus lateralis (13 +/- 3.5% and 27 +/- 4.4%), similar increase was observed from the start to the end in the rectus femoris and the vastus medialis (50 +/- 9.3% and 20 +/- 5.7%, respectively). Greater normal force along with enhanced activation of knee and hip extensor muscles is linked with fatigue and declines in cadence of triathletes during cycling to exhaustion.

Slackline training and postural control in older adults: A systematic review and meta-analysis.

BACKGROUND: Exercise can reduce the negative effects of aging on postural control. The slackline training could potentially be an activity to improve postural control in older adults. However, the effects of slackline on postural control in older adults are not clear. This systematic review aimed to investigate the effects of slackline on postural control in older adults. METHODS: Randomized controlled trials were retrieved from ISI Web Knowledge, PubMed and Scopus using the descriptors "Slackline", "Slacklining", "Aged", "Aging", "Elderly", "Older adults", "Balance", "Postural Balance" and "Postural Control". Randomized controlled trials were selected. Postural control was evaluated through center of pressure (CoP), and slackline standing time during single leg stance. RESULTS: Four studies with 118 participants were included. The studies found that slackline improves slackline standing time in the tandem, and the single-legged postures, without differences in CoP displacement in single-leg position, results that were confirmed by the meta-analyses. CONCLUSION: Although slackline training improves task-specific performance, this improvement is not transferable to other tasks. This conclusion should be interpreted with caution considering the small number of studies, inconsistent designs, and general study limitations. Further studies are required before recommending slackline training to optimize the postural control of older adults.

Effects of 24 h Compression Interventions with Different Garments on Recovery Markers during Running.

Compression and temperature manipulation are discussed as strategies to improve performance markers and recovery in sports. Here, we investigate the effects of compression stockings made with fabric, either combined or not with heating and cooling substances, on variables related to running performance and recovery. Ten trained runners (mean ± standard deviation age 45 ± 9 years old, body mass 69 ± 7 kg, height 166 ± 4 cm) with no experience of using compression garments performed an intense running session of 10 km, then wore a stocking for 24 h (randomized; without compression, compression, compression with camphor, and compression with menthol), and were evaluated on the following day, after running 5 km. The different types of compression stockings used 24 h before exercise did not affect running kinematics (p > 0.14), skin temperature (p > 0.05), heart rate (p > 0.12; mean value of maximal heart rate 156 bpm), comfort perception (p = 0.13; mean value of 7/10 points), or perception of recovery (p = 0.13; mean value of 7/10 points). In general, there were no effects of 24 h pre-exercise lower leg compression, including those treated with menthol and camphor applications on running kinematics, skin temperature, heart rate, or recovery perception in athletes undertaking consecutive running exercises.

Multicomponent Training Prevents Memory Deficit Related to Amyloid-ß Protein-Induced Neurotoxicity.

BACKGROUND: Alzheimer's disease (AD) is characterized by the accumulation of the amyloid-ß peptide in the brain, leading to early oxidative stress and neurotoxicity. It has been suggested that physical exercise could be beneficial in preventing AD, but studies with multicomponent training are scanty. OBJECTIVE: Verify the effects of multicomponent exercise training to prevent deficits in recognition memory related to Aß neurotoxicity. METHODS: We subjected Wistar rats to multicomponent training (including aerobic and anaerobic physical exercise and cognitive exercise) and then infused amyloid-ß peptide into their hippocampus. RESULTS: We show that long-term multicomponent training prevents the amyloid-ß-associated neurotoxicity in the hippocampus. It reduces hippocampal lipid peroxidation, restores antioxidant capacity, and increases glutathione levels, finally preventing recognition memory deficits. CONCLUSION: Multicomponent training avoids memory deficits related to amyloid-ß neurotoxicity on an animal model.

Effects of workload on seat pressure while cycling with two different saddles.

INTRODUCTION: Seat pressure during cycling and its relationship to urological disorders have been discussed extensively in recently published literature. The effects of exercise configuration on seat pressure, however, still have not been fully investigated. AIM: This study evaluates the effects of two different pedaling workloads and two saddle designs on saddle pressure in 22 (11 men and 11 women) recreational cyclists (bicycling <2 hours per week). METHODS: Seat pressure was measured in the saddle surface while pedaling at workloads of 150 and 300 W using a plain and a holed saddle model, both without any gel cushion characteristics. Analysis of variance was applied to compare seat pressure between situations. MAIN OUTCOME MEASURE: Study the importance of bicycle saddle pressure. RESULTS: Mean seat pressure was not different between men and women. For the plain saddle, the men's average seat pressure increased as the workload increased. Using a holed saddle, the mean pressure increased as the workload increased, regardless of gender. CONCLUSIONS: The increase of workload increased the seat pressure for the subjects, with the main effects dependent on workload. The use of a holed saddle was not directly related to lesser seat pressure during cycling. Our results support our understanding of a similarity between genders related to mean seat pressure, and suggest that different workload ranges may present different results for seat pressure.

Bicycle saddle pressure: effects of trunk position and saddle design on healthy subjects.

OBJECTIVE: There is a common belief that seat pressure during cycling can compress specific neurovascular tissues over the perineum leading to genital pathologies. This topic has seldom been discussed for women. The present study was conducted to verify the effect of trunk position and saddle design on saddle pressure in both men and women. METHODS: Recreational cyclists (11 men and 11 women) were evaluated while seated on a bicycle. Saddle pressure was measured with F-scan insoles adapted for two saddle models (with and without a hole), and two trunk positions (upright and forwards). Pressure values were compared between trunk positions and saddles employing ANOVA. RESULTS: There were no statistical differences comparing saddle pressure between the two trunk positions for women. For men a statistical difference between the trunk positions for the saddle with a hole was found. Thus, the trunk forwards shift seems to affect the values of saddle pressure only for men using the 'holed' saddle. CONCLUSION: Saddle pressure for men was influenced by saddle design and trunk position only. This result indicates that the masculine anatomy may influence saddle pressure during bicycle.

Sport biomechanics before and after the rio 2016 paralympic games / Biomecánica del deporte antes y después de los juegos paralímpicos rio 2016 / Biomecânica do esporte antes e depois dos jogos paralimpícos rio 2016

ABSTRACT Introduction: Events such as the Paralympic Games leave a series of legacies in the host societies. This is also applicable to the development of associated scientific knowledge, particularly in the field of sports biomechanics. Objective: The objective of this study is to investigate the Brazilian scientific production in the field of biomechanics in Paralympic sports during the cycle that preceded and followed the Rio 2016 Paralympic Games. Additionally, the study aims to provide insights for future research endeavors. Methods: The search was conducted on the Lattes Platform, utilizing the filters "Assunto" and "Doutores" and the keywords "Paralímpico" and "Paralympic." In total, 723 authors were identified who published articles related to the topic. Subsequently, the curricula were accessed, and the articles were sorted and identified, resulting in 37 articles that met all inclusion criteria. Results: The results indicate that: a) Brazil witnessed an increase in the number of publications after London 2012; b) The majority of these productions (87%) originate from Public Institutions; c) There was a greater participation of other regions of Brazil in the production of knowledge in the area after Rio 2016; d) Individual modalities such as powerlifting and athletics were the most researched, despite Brazil's reference status in some collective modalities; e) Women remain a minority, both as participants in research and as authors of publications; f) The productions demonstrate high levels of quality; g) The most commonly used research techniques in biomechanics were kinematics and dynamometry. Conclusion: The field of biomechanics in Paralympic sports has significantly benefited from the legacy generated by the Rio 2016 Paralympics. As future challenges for researchers, the following aspects stand out: maintaining the quality of productions, expanding studies to include collective modalities, increasing the participation of other federated entities in the production of knowledge in this field, promoting greater gender equity, and incorporating new research techniques in biomechanics. Level of Evidence II; Review Study.

RESUMEN Introducción: Eventos como los Juegos Paralímpicos dejan una serie de legados en las sociedades anfitrionas. Esto también es aplicable al desarrollo de conocimiento científico asociado, especialmente en el campo de la biomecánica deportiva. Objetivo: El objetivo de este estudio es investigar la producción científica brasileña en el campo de la biomecánica en deportes paralímpicos durante el ciclo que precedió y siguió a los Juegos Paralímpicos de Río 2016. Además, el estudio tiene como propósito brindar ideas para futuros esfuerzos de investigación. Métodos: La búsqueda se realizó en la Plataforma Lattes, utilizando los filtros " Assunto " y "Doutores" y las palabras clave "Paralímpico" y "Paralympic". En total, se identificaron 723 autores que publicaron artículos relacionados con el tema. Posteriormente, se accedió a los currículos y se clasificaron e identificaron los artículos, lo que resultó en 37 artículos que cumplieron con todos los criterios de inclusión. Resultados: Los resultados indican que: a) Brasil experimentó un aumento en el número de publicaciones después de Londres 2012; b) La mayoría de estas producciones (87%) provienen de Instituciones Públicas; c) Después de Río 2016, hubo una mayor participación de otras regiones de Brasil en la producción de conocimiento en el área; d) Las modalidades individuales, como levantamiento de pesas y atletismo, fueron las más investigadas, a pesar del estatus de referencia de Brasil en algunas modalidades colectivas; e) Las mujeres siguen siendo una minoría, tanto como participantes en investigaciones como autoras de publicaciones; f) Las producciones demuestran altos niveles de calidad; g) Las técnicas de investigación más utilizadas en biomecánica fueron la cinemática y la dinamometría. Conclusión: El campo de la biomecánica en deportes paralímpicos ha sido significativamente beneficiado por el legado generado por los Juegos Paralímpicos de Río 2016. Como desafíos futuros para los investigadores, se destacan los siguientes aspectos: mantener la calidad de las producciones, ampliar los estudios para incluir modalidades colectivas, aumentar la participación de otras entidades federadas en la producción del conocimiento en este campo, promover una mayor equidad de género e incorporar nuevas técnicas de investigación en biomecánica. Nivel de Evidencia II; Estudio de Revisión.

RESUMO Introdução: Eventos como os Jogos Paralímpicos deixam uma série de legados nas sociedades que as sediam. Não seria diferente quando se trata do desenvolvimento do conhecimento científico associado, em especial a biomecânica do esporte. Objetivo: Investigar a produção científica brasileira produzida em biomecânica no esporte paralímpico no ciclo que antecedeu e sucedeu os Jogos Paralímpicos Rio 2016, além de fornecer insights para novos estudos. Métodos: Foram realizadas buscas na Plataforma Lattes, sendo habilitados os filtros "Assunto" e "Doutores", com as palavras-chave "Paralímpico" e "Paralympic". Ao todo, foram encontrados 723 autores que publicaram artigo(s) relacionado(s) com o tema. Após acessar os currículos, os artigos foram triados e identificados, resultando em 37 artigos que preencheram todos os critérios de inclusão. Resultados: Os resultados mostram que a) Após Londres-2012, o Brasil tem aumentado o número de publicações; b) Grande parte das produções (87%) são oriundas de Instituições Públicas, c) Após Rio-2016 houve uma maior participação de outras regiões do Brasil na produção do conhecimento na área, d) Apesar do Brasil ser referência em algumas modalidades coletivas, modalidades individuais como o powerlifting e o atletismo, são as mais pesquisadas, e) Mulheres ainda são minoria, tanto como participantes das pesquisas quanto na autoria das publicações, f) As produções atingem elevados extratos de qualidade, g) As técnicas de pesquisa em biomecânica mais utilizadas foram a cinemática e dinamometria. Conclusão: A biomecânica no esporte paralímpico tem se valido do legado gerado pelas paralimpíadas Rio-2016. Como desafios futuros para os pesquisadores, destacam-se: manutenção da qualidade das produções, ampliação dos estudos para as modalidades coletivas, aumento da participação de outros entes federados na produção do conhecimento na área, promoção de uma maior equidade de gênero e incorporação de novas técnicas de pesquisa em biomecânica. Nível de Evidência II; Estudo de Revisão.

O uso do calçado habitual influencia o controle postural? / The use of normal shoes can influence the postural control?

Embora o uso de um calçado faça parte do dia a dia da maioria das pessoas, ao avaliar o controle postural na postura em pé quieta, muitos estudos consideram uma condição descalço. Assim, as pessoas diariamente convivem com uma condição onde utilizam calçados, e são avaliadas em uma condição diferente. A justificativa muitas vezes é que o calçado pode influenciar a avaliação. Contudo, pode o calçado habitual de fato influenciar o controle postural estimado pela trajetória do centro de pressão? Para responder a esta pergunta, avaliamos 14 adultos jovens com média de idade de 23 ± (4) anos, estatura de 1,63 ± (0,05) m e massa corporal de 59 ± (7) kg. Eles mantiveram a posição em pé, com apoio bipodal, com e sem usar o seu próprio calçado, com olhos abertos e fechados. Uma plataforma de força foi utilizada para aquisição de forças e momentos de reação do solo. Os dados foram utilizados para o cálculo do centro de pressão. Nenhuma das variáveis do centro de pressão (amplitudes, área e velocidade) diferiu entre as condições calçado e descalço, tanto com olhos abertos quanto fechados. Em resumo, o calçado habitual não influenciou as amplitudes, área e velocidade de oscilação do centro de pressão durante a postura em pé quieta....(AU)

Although using shoes is part of the daily context for most people, when postural control is assessed participants are subject to a barefoot condition. The most often reason for this is based in a possible effect of the footwear on the postural control. However, does the habitual footwear influence postural control estimated by center of pressure traces? To address this question we evaluated 14 young adults with mean age of 23 ± (4) years old, height 1.63 ± (0.05) m and body mass 59 ± (7) kg. They stand still with bipedal support using or not their habitual shoe, for trials with eyes open and closed. A force plate was used to record ground reaction forces and moments. Data were used to determination of center of pressure. None of the center of pressure variables (amplitudes, area and velocity) differed between the shod and barefoot conditions regardless of eyes open or closed. In summary, the habitual footwear did not influence postural oscillation during upright standing in young adults....(AU)

Change of Pronation Angle of the Subtalar Joint has Influence on Plantar Pressure Distribution / Alteração do Ângulo de Pronação da Articulação Subtalar tem Influência na Distribuição de Pressão Plantar: Um Estudo Preliminar

Abstract Several studies have investigated the relationship between heel pronation with plantar pressure during gait. With a degree of variability and influence of the footwear, usually excessive pronation is associated with higher mechanical loads. However, larger loads are commonly associated with pronation. his study aims to compare the plantar pressure distribution among individuals with different pronation angles of the subtalar joint angle during gait with controlled speed. he maximum angle of the subtalar joint was determined by capturing images in the frontal plane and the pressure plant peaks were acquired by EMED pressure platform. he pronated group showed pressure plant peaks significantly higher in the lateral heel area (18%; p=0.031), medial heel (17%, p=0.034), lateral midfoot (30%; p=0.032) and medial midfoot (41%; p=0.018) when compared to the control group. Excessive pronation of the subtalar joint caused changes in plantar pressure distribution, and an increase in pressure plant peaks, especially in the heel and midfoot regions. This demonstrates the need for a specific care of this population, mainly because the increased pressure plant peaks is related to pain in the feet and onset of injuries.

Resumo Diversos estudos investigaram a relação da pronação da articulação subtalar com a pressão plantar na marcha. Com certo grau de variabilidade e influência do calçado, geralmente uma pronação excessiva está associada a cargas mecânicas mais elevadas. Contudo, popularmente se associa qualquer índice de pronação com aumento das cargas. Neste estudo buscamos comparar a distribuição de pressão plantar entre indivíduos com diferentes comportamentos do ângulo de pronação da articulação subtalar durante a marcha com velocidade controlada. O ângulo máximo de pronação da articulação subtalar foi determinado por meio da aquisição de imagens no plano frontal e os picos de pressão plantar foram adquiridos através da plataforma de pressão EMED. O grupo pronado apresentou picos de pressão plantar significativamente mais elevados na região do calcanhar lateral (18%; p=0,031), do calcanhar medial (17%, p=0,034), do mediopé lateral (30%; p=0,032) e do mediopé medial (41%; p=0,018) quando comparado ao grupo controle. A excessiva pronação da articulação subtalar provocou alterações na distribuição de pressão plantar, com aumento nos picos de pressão plantar, principalmente nas regiões do calcanhar e do mediopé. Isto demonstra a necessidade de um cuidado especifico em relação e este público, principalmente pelo aumento dos picos de pressão plantar estar relacionado com dores nos pés e com o surgimento de lesões.

Kinetic asymmetries between forward and drop jump landing tasks / Assimetrias cinéticas entre saltos para frente e saltos de queda

Abstract Landing asymmetry is a risk factor for knee anterior cruciate ligament injury. The aim of this study was to identify kinetic asymmetries in healthy recreational athletes performing different jump-landing techniques. Twelve recreational athletes engaged in regular training underwent kinetic evaluation using two 3D force plates and were analyzed for: (a) three-dimensional peak forces, (b) time to peak vertical force, and (c) initial phase asymmetries. All data were collected during performance of unilateral and bilateral trials of forward and drop jump tasks. Forward jump-landing tasks elicited greater kinetic asymmetry than drop-landing tasks. Regardless of jump-landing technique, the preferred leg experienced higher forces than the non-preferred leg. The initial landing phase showed more kinetic asymmetries than the later phase when peak vertical forces occur. It was concluded that when screening athletes for kinetic asymmetries that may predispose them to injury, forward jump-landing tasks and the early landing phase might show more kinetic asymmetries than drop jump-landing tasks and the late landing phase, respectively.

Resumo Assimetrias durante a aterrissagem de tarefas de salto são um fator de risco para lesão de ligamento cruzado anterior do joelho. O objetivo deste estudo foi identificar assimetrias cinéticas em atletas recreacionais saudáveis, enquanto realizavam diferentes tarefas de salto e aterrissagem. Doze atletas recreacionais que treinavam regularmente realizaram uma avaliação cinética, em que foram avaliadas as seguintes variáveis: (a) pico das forças de reação do solo (nas três componentes), (b) tempo para o pico de força vertical, e (c) assimetrias na fase inicial da aterrissagem. Os dados foram coletados durante a execução de saltos unilaterais e bilaterais, assim como de saltos para frente e saltos de queda. Saltos para frente demonstraram maiores assimetrias cinéticas comparados com os saltos de queda. Independente do tipo de salto, a perna preferida recebeu maiores cargas se comparada com a perna não preferida. A fase inicial da aterrissagem foi mais sensível na detecção de assimetrias cinéticas do que a fase mais tardia da aterrissagem, quando ocorrem os picos de força. Pode-se concluir que as avaliações para detectar assimetrias cinéticas em atletas, saltos para frente e a fase inicial da aterrissagem parecem ser mais sensíveis para a detecção dessas assimetrias.

Saúde no parque: características de praticantes de caminhada em espaços públicos de lazer / Health in the park: characteristics of people walking in public areas of leisure

A prática regular de caminhada pode tornar a população mais ativa fisicamente. Buscamos relatar as atividades desenvolvidas com praticantes de caminhada em ambientes públicos de lazer em Uruguaiana - RS. Os participantes foram entrevistados, avaliados fisicamente, e divididos em faixas etárias. Resultados sugerem que idosos têm maior frequência e são motivados pela orientação médica. Jovens assumem prazer na realização da prática. Adultos de meia idade são maioria, e se exercitam pela preocupação com a saúde. Alterações posturais observadas sugerem precaução quanto ao tipo e forma de atividade física praticada, mostrando a necessidade de maior orientação profissional em espaços de lazer.

Walking can help people become physically active. We present a report concerning activities developed with walkers in a public space for leisure in Uruguaiana - RS. Participants were interviewed, underwent a simple physical examination and divided into age groups. Elderly are more frequent in weekly activities, motivated by medical personnel. Young people indicated enjoyment when performing walking or running. Middle-aged adults are the majority, and exercise for health concerns. The concerns of users and postural alterations suggest concern regarding the modality and development of the physical activity, denoting that the professional orientation in these leisure spaces should be considered.

Influence of running distance on plantar pressure / Influência da distância de corrida na pressão plantar

Running is a popular sport performed at different places and involving different distances and modalities. Long distance running promotes cumulative loading on joints and soft tissues that could determine important biomechanical alterations. A tool for assessing such loads is the measurement of plantar pressure. Here we compared static plantar pressure before and after 10 km and 21 km running competitions. Twenty trained runners participated in this study. They were assigned to 10 km (n=10) or 21 km (n=10) group according to their competition distance. Static plantar pressure was assessed in the day before competition and quickly after competition finished. Mean plantar pressure was compared between pre and post competition, between groups, legs and foot regions. Static plantar pressure did not differ between feet in either groups. In 10 km runners, higher plantar pressure post competition was observed in the forefoot, while any changes were observed in the 21 km group. Differences in plantar pressure between foot regions were similar between groups. In summary, static assessment of plantar pressure seemed more sensitive to changes in plantar pressure after a 10 km running, but not after 21 km. After 10 km running, forefoot experiences higher plantar pressure.

A corrida é um esporte popular praticado em vários locais e em diversas modalidades e distâncias. Corridas de longa distância promovem cargas cumulativas e repetidas sobre articulações e tecidos moles que podem refletir alterações biomecânicas importantes. Uma ferramenta para avaliar essas cargas é a medida de pressão plantar. Aqui comparamos a pressão plantar estática antes e após uma competição, entre corredores de 10 km e 21 km. Vinte corredores treinados participaram deste estudo. Eles formaram dois grupos, chamados de 10 km (n=10) e 21 km (n=10), conforme a modalidade da sua competição. Todos tiveram a pressão plantar estática avaliada no dia anterior e logo após o término da competição. A pressão plantar média foi comparada entre as condições pré e pós-corrida, entre os grupos, entre os pés e entre as regiões dos pés, pré e após a competição. A pressão plantar estática foi simétrica entre os pés em ambos os grupos. Para corredores de 10 km, maior pressão plantar foi observada no antepé após competição, enquanto nenhuma mudança ocorreu após 21 km. Diferenças entre as regiões do pé foram similares em ambos os grupos. Em conclusão, a avaliação estática parece mais sensível a mudanças após 10 km de corrida, mas não após 21 km. Após 10 km de corrida, o antepé apresenta aumento na pressão plantar.

Relação entre sensibilidade plantar e controle postural em jovens e idosos / Relationship between foot sensibility and postural control in the young and elderly

A diminuição da sensibilidade plantar em idosos acarreta alterações na locomoção e no controle postural que podem aumentar o risco de quedas. Compreender o uso de aferências podais em idosos pode auxiliar na prevenção da perda de mobilidade e quedas. Contudo, a relação entre a sensibilidade de diferentes regiões do pé e alterações no controle postural representa uma lacuna na literatura. Com o propósito de investigar esta lacuna na literatura, o objetivo deste estudo foi avaliar a relação entre a sensibilidade plantar e o controle postural em jovens e idosos. Foram avaliados 42 participantes, organizados em dois grupos de acordo com a faixa etária (jovens ou idosos). Os participantes foram avaliados quanto às características antropométricas, sensibilidade dos pés (usando monofilamentos) e controle postural (usando plataforma de força). Os índices de sensibilidade plantar e de controle postural foram correlacionados e comparados entre os grupos. Os resultados mostraram que idosos tiveram menor sensibilidade dos pés e pior controle postural do que jovens. A amplitude ântero-posterior e a área do centro de pressão de idosos tiveram correlação com a sensibilidade plantar geral, mas não com regiões específicas do pé. Para jovens, a sensibilidade na região do antepé esteve relacionada com o melhor controle postural.

Impairments in the foot sensitivity in the elderly cause changes in locomotion and postural control that may increase fall risk. Understanding the use of foot afference in the elderly may help preventing loss of mobility and fall. However, there are few studies addressing the relation between the sensitivity of different foot regions and postural control. To investigating this lack in literature, the objective of our study was to assess the relationship between foot sensibility and postural control in young and elderly. Forty-two subjects volunteered to this study; they were assigned to a group according to their age (young or elderly). The participants were assessed regarding anthropometry, foot sensibility (using monofilaments) and postural control (using a force plate). The indexes of foot sensibility and postural control were correlated and compared between the groups. Elderly had worst foot sensibility and postural control than young. Center of pressure are and amplitude in antero-posterior direction were correlated with the general foot sensibility, but not with a specific point of the foot in the elderly. For young, the sensitivity in the forefoot region was related to improved postural control.

Effects of a program for trunk strength and stability on pain, low back and pelvis kinematics, and body balance: a pilot study.

The purpose of this pilot study was to investigate the effects of trunk strength and stability training on body balance and low back and pelvis kinematics during gait in females. Six subjects volunteered to do 20 sessions of training. Data collection involved a qualitative pain grade test, low back stabilization tests, low back and pelvis kinematics, and body balance assessment. Results indicate the absence or decrease in the low back pain, and also an increase in the stabilization and strength of low back and pelvis complex. The 3-D kinematics showed statistically significant differences (p<0.05) when compared pre- to post-training. The body balance was improved as well as the range of motion (ROM) was improved for trunk rotation, pelvis inclination and low back flexion. The results suggest the influence of trunk strength and stability on low back and pelvis pain and kinematics as well as on body balance. Further studies with a larger sample and/or a control group must be conducted in an attempt to confirm this hypothesis.

Efeito da altura do selim na cinemática da lombar de ciclistas / Effect of saddle height on the kinematics of lumbar spine of cyclists

O objetivo deste estudo foi analisar a influência da altura do selim sobre a cinemática da coluna lombar durante o ciclismo. Foram avaliados oito ciclistas recreacionais, na situação usual (auto ajustada) e na situação de selim ajustado, com carga de 150 W, utilizando-se avaliação cinemática bidimensional em um ciclosimulador. Foram mensurados os ângulos de flexão, inclinação lateral e rotação da coluna lombar. A flexão da lombar foi maior na situação de selim ajustado, enquanto que a inclinação e a rotação da lombar foram maiores na situação de ajuste usual. Quanto ao comportamento ao longo do ciclo de pedalada, ocorreram dois ciclos de flexão-extensão durante um ciclo completo do pé-de-vela, e apenas um ciclo de inclinação lateral ou de rotação. As maiores diferenças acorreram no início, meio e fim do ciclo. O ajuste equivocado do selim não acarreta alterações na cinemática da coluna lombar.

The aim of this study was to analyze the influence of saddle height on the kinematics of the lumbar spine during cycling. Eight recreational cyclists were assessed in an usual situation (self-selected) and the situation of saddle properly adjusted while pedaling with a load set at 150 W. Using two-dimensional kinematic the angles of flexion, lateral inclination and rotation of the lumbar spine were computed. The flexion was greater in the adjusted position whereas the highest average tilt and rotation angles occurred in the usual position. There were two cycles of flexion-extension observed during a complete pedaling cycle, and only one cycle of lateral inclination and rotation. The major differences were observed at early, middle and end of the pedaling cycle. The mismanagement of the saddle did not involve significant changes in the kinematics of the lumbar spine for the conditions tested.

Preference and torque asymmetry for elbow joint / Preferência e assimetria de torque na articulação do cotovelo

Extensively unilateral recruitment for daily activities may determine performance asymmetries in favor of the preferred side eliciting functional adaptation. Our study evaluated asymmetries in elbow torque output between preferred and non-preferred limbs. Eighteen subjects performed maximal elbow flexor and extensor isometric contractions at five different elbow joint angles (0º, 30º, 60º, 90º, 120º) and five different angular velocities (60, 120, 180, 240, 300º.s-1) on an isokinetic dynamometer. Higher flexor torque in favor of preferred arm was observed at 90º of flexion (p<0.05), which also corresponded to the highest torque produced (p<0.05). The fact that joint angle influenced torque asymmetries, whereas angular velocity did not, suggest that the observed asymmetry is likely related to preferential recruitment of elbow flexors at a 90º joint angle for daily tasks requiring high levels of force production. Muscle functional adaptation to frequent stimuli at this joint angle in healthy subjects may explain these results.

O frequente recrutamento unilateral de membros superiores pode determinar assimetrias de desempenho em favor do lado preferido, resultando em adaptação funcional. Assimetrias no torque gerado pelos músculos do cotovelo entre o membro preferido e não-preferido foram avaliadas. Dezoito sujeitos realizaram contrações máximas de flexo-extensão do cotovelo em cinco ângulos articulares (0º, 30º, 60º, 90º, 120º) e cinco velocidades angulares (60, 120, 180, 240, 300º.s-1) em um dinamômetro isocinético. Torque flexor mais elevado em favor do lado preferido foi encontrado no ângulo de 90º (p<0,05), que também correspondeu ao ângulo de maior torque (p<0,05). O fato de o ângulo articular determinar assimetrias no torque (enquanto a velocidade angular não) sugere que o recrutamento preferencial dos flexores do cotovelo em um ângulo de 90º nas tarefas da vida diária que requerem força elevada é responsável pela assimetria. Adaptação funcional a estímulos frequentes nesse ângulo articular pode explicar esses resultados em sujeitos saudáveis.

Influência da pedalada com os joelhos tangenciando o quadro da bicicleta sobre a ativação dos músculos do membro inferior / Effects of cycling with the knees close to the bicycle frame on the lower limb muscle activation

A mudança da posição do corpo sobre a bicicleta tem sido relacionada a alterações na ativação dos músculos do membro inferior. Desta forma, o objetivo do presente estudo foi comparar a ativação dos músculos "Tibialis Anterior", "Gastrocnemius Medialis", "Biceps Femoris", "Rectus Femoris", "Vastus Lateralis", "Adductor Longus" e "Gluteus Maximus" nas seguintes situações: 1) posição de referência (posição preferida); 2) posição de adução (joelhos tangenciando o quadro da bicicleta); 3) posição de abdução (joelhos afastados do quadro da bicicleta). Seis atletas com experiência competitiva em ciclismo foram avaliados por meio da eletromiografia de superfície (EMG). Todos pedalaram em suas próprias bicicletas montadas em um ciclosimulador, com carga de trabalho normalizada pelo VO2 de forma que a taxa de troca respiratória se mantivesse entre 0,8 e 1,0. A ativação muscular foi analisada por meio da comparação da média do envelope RMS e do período de ativação para cada um dos músculos, nas três posições avaliadas. Não foram observadas diferenças significativas para a média do envelope RMS e para o período de ativação dos músculos nas três posições avaliadas, à exceção do "Adductor Longus". Observou-se maior ativação (36 ± 6 por cento) deste músculo na posição de adução comparado a posição de abdução (25 ± 11 por cento) para um valor de significância de p = 0,02, sem diferenças em relação a posição de referência (27 ± 7 por cento). Estes resultados sugerem que não ocorrem alterações substanciais na ativação dos principais músculos do membro inferior quando a posição dos joelhos no plano frontal é alterada e a carga de trabalho é mantida, à exceção do aumento da participação do "Adductor Longus".

Cyclist's body position on the bike has been related to changes in muscle activation. Therefore, the aim of the present study was to compare the activation of Tibialis Anterior, Gastrocnemius Medialis, Biceps Femoris, Rectus Femoris, Vastus Lateralis, Adductor Longus e Gluteus Maximus muscles in three conditions: 1) reference position (preferred position); 2) adduction position (knees almost touching the bicycle frame); 3) abduction position (knees away from the bicycle frame). Six athletes with competitive experience in cycling were evaluated using surface electromyography. They pedalled using their own bicycles mounted on a wind-trainer, with a workload relative to the second ventilatory threshold. Muscle activation was defined by the mean value of the RMS envelope and by the activation period for the three evaluated positions. There were no significant differences in muscles' RMS or activation period between the three positions, except for the Adductor Longus muscle. In adduction position, this muscle was more activated (36 ± 6 percent), compared to the abduction position (25 ± 11 percent) for a significance level of p = 0.02, without significant differences for the reference position (27 ± 7 percent). These results indicate that there is no substantial difference in the activation of the most important muscles of the lower limb when the position of the knee is changed in the frontal plane for the same workload level, with the Adductor Longus as an exception.