High index of cervical and lumbar pain had been registered in cyclists. Factors as a posture adopted on bicycle, the activity of spine extensor muscles and the action of mechanical load in the spine structures had been put like possible causes of pain. Although related and apparently accepted, few studies investigate these factors. In addition, the non-specific chronic pain is frequently diagnosed in cyclists, because few evidences of abnormalities are investigated when clinic radiologics exams are done. The use of biomechanical methods of investigation, like the estimate of muscular force magnitude of extensors of spine and of joint force in different levels of spine can be contributed to evaluation of injury risk and pain caused by cycling, beyond the assist in strategies of prevention and rehabilitation programs. Therefore, this study had like objective to quantify and compare the active internal forces in the cervical spine during cycling in different postures, through development and application of three dimensional in vivo biomechanical model. The biomechanical model suggested was compound by two rigid segments (upper and lower cervical spine) connected. The upper cervical spine segment include head, C1 and C2. The lower cervical spine segment include cervical vertebraes of C3 to C7. In the upper cervical spine segment are considered two vectors of muscular force: FM1 (rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior e obliquus capitis inferior) and FM2 (semispinalis capitis e splenius capitis). In the lower cervical spine segment are included the vectors FM3 (semispinalis cervicis) and FM4 (splenius cervicis). The resolution of movement equation of Newton-Euler is done through inverse dynamics. The kinematic parameters were obtained using external images of head and cervical spine, acquired by four digital video cameras with sampling frequency of 25 Hz. To estimate the location of rotation centers (C2-3 and C6-7) statics conventional radiologic exams were done. The parameters of mass and center of mass were removed of anthropometric tables of literature. 12 cyclists with at least two years of competitive experience each one participated of the study. The study was approved by Ethics Committee in Researches of Federal University of Rio Grande do Sul and the subjects signed a free and clear consent term. Each participant was assessed using your bicycle attached in a magnetic cycle simulator, in two stages done in the same day. Initially the total body mass of subjects was measured and then 14 anatomic points of interest were identified and marked with a dermatography pen. During the evaluation markers encased with reflective paper and containing lead inside of these markers were fixed in all anatomic points of interest. In the stage I the subjects rode a bicycle during 2 minutes in each posture (upright neutral, rest, intermediate, attack and flexed elbows). The kinematic data were collected during the last 30 seconds of each one. In the stage II static radiologic exams were done in each of 5 analyzed postures (upright neutral, rest, intermediate, attack and flexed elbows) and in maxim flexion and extension of cervical spine. The results indicate that the internal forces active in the structures of cervical spine presented more magnitudes in the postures that involve the cycling practice (rest, intermediate, attack and flexed elbows), when compared to reference posture (upright neutral). Observing just the postures that involve the cycling, the internal forces gradually increased as cyclists transferred the your hands from upper to lower region of handlebar, adopting the rest, intermediate and attack postures, respectively. However, the greater magnitude of internal forces were observed when the cyclists hands involving the brake levers and flexed the elbow joints (flexed elbows posture). Proportionally the greatest increase of internal forces occurred in the upper cervical spine, however the greatest magnitudes of internal forces were reached in the lower cervical spine. The evaluation process demonstrated that the three dimensional biomechanical model of cervical spine was considered able to represent of reliable way the interest system. The results found are coherent, the

Modelo biomecânico tridimensional para análise das forças internas atuantes na coluna cervical superior e inferior durante o ciclismo

The goal of this study is propose a method to calculate the patellofemoral contact force in vivo during a dynamic activity. In order to do that, is intended to operacionalize a protocol to determine the biomechanical parameters of the tibiofemoral and patellofemoral joints using inverse dynamics. To determine such parameters were used dynamic radiographycal images, obtained in the sagital plane, from one individual executing an exercise of knee’s extension in open kinetic chain, without external load. The images obtained were reproduced and digitalized using a capture plate Silicon Graphics 320. Computer routines were developed with the software Matlab® to analyze the data. The results suggest that the use of inverse dynamics as a way to determine the patellofemoral contact force is appropriated. Key-words: contact force, patelofemoral, inverse dynamics

Proposta metodológica para o cálculo da força de contato patelofemoral

ESTUDIO DE LOS CENTROS DE ROTACIÓN INSTANTÁNEOS DE LA RODILLA EN PACIENTES CON PLASTIA DEL LIGAMENTO CRUZADO ANTERIOR Tesis presentada como uno de los requisitos para obtener el título de Magister en Ciencias Médicas, mención en Biomecánica Clínica

OBJETIVO: Operacionalizar um protocolo para a correcao de imagens obtidas por videofluoroscopia a partir de um modelo matematico descrito por Baltzopoulos (1995) e avaliar a magnitude do erro pelos metodos de calibracao linear e nao linear. MATERIAIS E METODOS: As imagens foram obtidas por meio de um videofluoroscopio da marca Axion Siemens Iconos R100 de um individuo realizando exercicio de extensao de joelho. Para a correcao das imagens foi utilizado padrao de calibracao nao-linear. O processamento dos dados foi realizado em placa de captura da marca Silicon Graphics 320 e posteriormente analisado em um "software" Matlab. RESULTADOS: Para demonstrar a aplicabilidade do metodo foi avaliada a deformacao do ligamento patelar. A utilizacao do padrao de calibracao linear produziu um erro maximo de 0,086 mm, enquanto o padrao de calibracao nao linear atingiu um valor maximo de 0,019 mm. Ja com relacao ao erro medio, a calibracao linear atingiu o valor de 0,024 mm, e a nao linear apresentou um valor de 0,007 mm. CONCLUSAO: Os resultados evidenciam a necessidade de utilizacao de um procedimento de calibracao nao linear.

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Método para a correção da distorção de imagens obtidas por videofluoroscopia

This work focuses on understanding what was at stake in the Porto Alegre City Council on January 2-July 12, 2017 regarding (re)production of meanings in sport, recreation and leisure as an intervention field of public-social interest and the collective action 'We’re All SME' (We all support the Porto Alegre Municipal Education Department) as a form of political struggle to maintain the Department. The study was based on an investigative experience of observant participation recorded through notes, field diaries, reports and documents produced. We also used official documents publicly available at Porto Alegre’ City Council and the Municipal Gazette. Driven by theoretical-conceptual issues from Pierre Bourdieu’s work, we developed an analytical-interpretative process that led us to conclude that what was at stake was the meanings of collective action increasingly interconnected in the public scene to demand the maintenance of the Municipal Education Department – rather than the meanings of sport, recreation and leisure as a field of intervention.

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Luis Felipe Silveira

Papers

Método para a correção da distorção de imagens obtidas por videofluoroscopia

Esporte, recreação e lazer nos jogos políticos: reflexões a partir da inserção numa ação coletiva em Porto Alegre