Paula Hentschel Lobo da Costa

Comparison of static footprints and pedobarography in obese and non-obese children.

Background: Static footprints have been widely used clinically. However, since this measure provides only indirect information about the medial longitudinal arch height, it is not clear if it can be indicative of dynamic foot function especially in obese children. This study aimed to verify whether static footprints can predict dynamic plantar pressures in obese children. Materials and Methods: Twenty children aged 9 to 11 years, divided into obese and non obese, voluntarily participated in this study. Static footprints and dynamic plantar pressures were analyzed by using a pedograph and the Pedar system (Novel GMbH, Munich, GER), respectively. Results: In general, correlations between static and dynamic measures were observed to be significant for the non obese children, while no significant correlations were found for the obese ones. Conclusion: Since obesity may affect the relationship between static and dynamic measures, footprints should be used with caution when inferring the characteristics of obese childrens feet under dynamic conditions. Clinical Relevance: Footprints and pedobarography should not be used at this time for clinical decision making regarding the feet of obese children.

Repetibilidade de medidas isocinéticas dos músculos adutores e abdutores do quadril

O objetivo deste estudo foi determinar a repetibilidade de medidas isocineticas dos musculos adutores e abdutores do quadril, a fim de verificar a possibilidade de suas aplicacoes clinicas em programas de treinamento e reabilitacao. Participaram do estudo sete voluntarios saudaveis, universitarios, ativos, do sexo masculino, com idade media de 22,8 ± 3,4 anos. Estes individuos foram submetidos a tres avaliacoes, em diferentes dias, para a obtencao do pico de torque concentrico e da media do pico de torque, unilateralmente. Em cada avaliacao foram realizadas cinco contracoes concentricas maximas continuas, em duas velocidades (30 e 90o/s), para os movimentos de aducao e abducao do quadril. Os dados foram obtidos por meio de um dinamometro isocinetico da marca Biodex. A analise estatistica foi realizada por meio de um ANOVA com medidas repetidas e coeficiente de correlacao intra-classe (ICC), considerando o nivel de significância de α ≤ 0,05. Pode-se observar que nao houve diferencas significativas entre as tentativas, considerando-se o pico de torque e a media do pico de torque (p >; 0,05); na analise do ICC entre a segunda e terceira avaliacao, os valores variaram de baixo a excelente (0,20 - 0,79) para a media do pico de torque e de moderado a excelente (0,52 - 0,79) para o pico de torque para ambas as velocidades. Esses resultados apontam para uma medida reprodutivel da performance isocinetica concentrica de musculos adutores e abdutores do quadril.

Footwear and Foam Surface Alter Gait Initiation of Typical Subjects.

Gait initiation is the task commonly used to investigate the anticipatory postural adjustments necessary to begin a new gait cycle from the standing position. In this study, we analyzed whether and how foot-floor interface characteristics influence the gait initiation process. For this purpose, 25 undergraduate students were evaluated while performing a gait initiation task in three experimental conditions: barefoot on a hard surface (barefoot condition), barefoot on a soft surface (foam condition), and shod on a hard surface (shod condition). Two force plates were used to acquire ground reaction forces and moments for each foot separately. A statistical parametric mapping (SPM) analysis was performed in COP time series. We compared the anterior-posterior (AP) and medial-lateral (ML) resultant center of pressure (COP) paths and average velocities, the force peaks under the right and left foot, and the COP integral x force impulse for three different phases: the anticipatory postural adjustment (APA) phase (Phase 1), the swing-foot unloading phase (Phase 2), and the support-foot unloading phase (Phase 3). In Phase 1, significantly smaller ML COP paths and velocities were found for the shod condition compared to the barefoot and foam conditions. Significantly smaller ML COP paths were also found in Phase 2 for the shod condition compared to the barefoot and foam conditions. In Phase 3, increased AP COP velocities were found for the shod condition compared to the barefoot and foam conditions. SPM analysis revealed significant differences for vector COP time series in the shod condition compared to the barefoot and foam conditions. The foam condition limited the impulse-generating capacity of COP shift and produced smaller ML force peaks, resulting in limitations to body-weight transfer from the swing to the support foot. The results suggest that footwear and a soft surface affect COP and impose certain features of gait initiation, especially in the ML direction of Phase 1.

Estudo dinamométrico da marcha de idosas ultrapassando obstáculos

O presente estudo teve como objetivo investigar a marcha durante a negociacao de obstaculos de mulheres idosas fisicamente ativas e sedentarias para identificar as adaptacoes realizadas pelos dois grupos diante de uma tarefa de marcha mais complexa. Participaram do estudo 20 idosas sadias, divididas entre grupo ativo e grupo sedentario. Foi utilizada uma plataforma de forca para avaliar a componente ortogonal vertical das forcas de reacao do solo: forcas maxima e minima, impulso vertical e tempo de apoio. Essas variaveis foram analisadas durante dois protocolos distintos: marcha livre e marcha com obstaculo com alturas de 10%, 20% e 30% do comprimento do membro inferior das voluntarias. O obstaculo foi posicionado previamente e apos a plataforma para que duas funcoes diferentes do mesmo membro inferior fossem investigadas. Os resultados estao apresentados em tres secoes: a primeira avalia os dois grupos (nao houve diferenca significativa), a segunda avalia o efeito da altura do obstaculo (onde a altura de 10% ja se apresenta como um obstaculo desafiante para as idosas sedentarias) e a terceira compara as funcoes de suporte primario e secundario (nao houve diferenca significativa). Conclui-se, para a amostra utilizada, que a atividade fisica auxiliou na negociacao de obstaculos durante a marcha. As idosas sedentarias optaram por uma estrategia mais segura na negociacao de obstaculos, observada pelas menores magnitudes das variaveis dinamometricas juntamente com um maior tempo de apoio.

Use of a backpack alters gait initiation of high school students

We assessed how backpack carriage influences the gait initiation (GI) process in high school students, who extensively use backpacks. GI involves different dynamics from gait itself, while the excessive use of backpacks can result in adverse effects. 117 high school students were evaluated in three experimental conditions: no backpack (NB), bilateral backpack (BB), and unilateral backpack (UB). Two force plates were used to acquire ground reaction forces (GRFs) and moments for each foot separately. Center of pressure (COP) scalar variables were extracted, and statistical parametric mapping analysis was performed over the entire COP/GRFs time series. GI anticipatory postural adjustments (APAs) were reduced and were faster in backpack conditions; medial-lateral COP excursion was smaller in this phase. The uneven distribution of the extra load in the UB condition led to a larger medial-lateral COP shift in the support-foot unloading phase, with a corresponding vertical GRF change that suggests a more pronounced unloading swing foot/loading support foot mechanism. The anterior-posterior GRFs were altered, but the COP was not. A possible explanation for these results may be the forward trunk lean and the center of mass proximity of the base of support boundary, which induced smaller and faster APA, increased swing foot/support foot weight transfer, and increased load transfer to the first step.

Effects of four days hiking on postural control.

Hiking is a demanding form of exercise that may cause delayed responses of the postural muscles and a loss of somatosensory information, particularly when repeatedly performed for several days. These effects may negatively influence the postural control of hikers. Therefore, the aim of this study was to investigate the effects of a four-day hike on postural control. Twenty-six adults of both sexes travelled 262 kilometers, stopping for lunch and resting in the early evening each day. Force platforms were used to collect center of pressure (COP) data at 100 Hz for 70 seconds before hiking started and immediately after arriving at the rest station each day. The COP time course data were analyzed according to global stabilometric descriptors, spectral analysis and structural descriptors using sway density curve (SDC) and stabilometric diffusion analysis (SDA). Significant increases were found for global variables in both the anterior-posterior and medial-lateral directions (COP sway area, COP total sway path, COP mean velocity, COP root mean square value and COP range). In the spectral analysis, only the 80% power frequency (F80) in the anterior-posterior direction showed a significant increase, reflecting the increase of the sway frequencies. The SDC revealed a significant increase in the mean distance between peaks (MD) and a significant decrease in the mean peak amplitudes (MP), suggesting that a larger torque amplitude is required for stabilization and that the postural stability is reduced. The SDA revealed a decrease in the long-term slope (Hl) and increases in the short-term (Ks) and the long-term (Kl) intercepts. We considered the likelihood that the presence of local and general fatigue, pain and related neuromuscular adaptations and somatosensory deficits may have contributed to these postural responses. Together, these results demonstrated that four days of hiking increased sway frequencies and deteriorated postural control in the standing position.

Gait Initiation in Older People: Concepts, Clinical Implications and Methodology

Anticipatory postural adjustments are necessary neuromuscular strategies to begin a new gait cycle and to safely take the first step forward. For this purpose, postural transients about to occur with imminent forward motion must be controlled. Impairments in this process must be understood in order to reveal pathophysiological mechanisms underlying dynamic balance problems in the older population. The aim of this chapter is twofold: to firstly explain the typical mechanism of gait initiation (GI), some aspects that affect its pattern and benefits of training interventions for the elderly population and, secondly, to describe computational methods to assess and quantify this mechanism based on force plate measurements.

A biomecânica e a produção do conhecimento em fisioterapia: levantamento baseado nos anais do congresso brasileiro de biomecânica

O aumento gradual da participacao da comunidade academica da Fisioterapia nas edicoes do Congresso Brasileiro de Biomecânica (CBB) e notorio. Os Anais do CBB passaram a ser importantes veiculos para a divulgacao cientifica em Fisioterapia no Brasil; porem, a caracterizacao dessa producao ainda nao foi feita. O objetivo do presente estudo foi realizar um levantamento bibliografico dos estudos em Fisioterapia publicados nas edicoes dos Anais do CBB, desde a primeira edicao em 1992 (Anais do IV CBB) ate a edicao publicada em 2009 (Anais do XIII CBB), a fim de identificar quais especialidades da Fisioterapia tem aplicado o conhecimento em Biomecânica no contexto clinico e/ou cientifico, alem de caracterizar o tipo de pesquisa que se tem desenvolvido. Seis revisores independentes levantaram os estudos pertencentes a area da Fisioterapia e coletaram informacoes de maneira padronizada atraves de questionarios. Os resultados evidenciaram um grande crescimento da participacao das diferentes areas da Fisioterapia ao longo das dez edicoes do CBB. Embora os dados sejam positivos em relacao a ampliacao das pesquisas em Biomecânica, verificou-se uma carencia da utilizacao dos recursos biomecânicos para avaliar efeitos de intervencoes em pacientes. Dessa forma, recomenda-se que mais estudos sejam conduzidos em contextos clinicos e com acompanhamento longitudinal, de modo a ampliar a aplicacao pratica das ferramentas biomecânicas no campo da intervencao, bem como aperfeicoar a avaliacao em Fisioterapia.