Effects of vestibular stimulation on gait stability when walking at different step widths.

Vestibular information modulates muscle activity during gait, presumably to contribute to stability. If this is the case, stronger effects of perturbing vestibular information on local dynamic stability of gait, a measure of the locomotor system's response to small, naturally occurring perturbations, can be expected for narrow-base walking (which needs more control) than for normal walking and smaller effects for wide-base walking (which needs less control). An important mechanism to stabilize gait is to coordinate foot placement to center of mass (CoM) state. Vestibular information most likely contributes to sensing this CoM state. We, therefore, expected that stochastic electrical vestibular stimulation (EVS) would decrease the correlation between foot placement and CoM state during the preceding swing phase. In 14 healthy participants, we measured the kinematics of the trunk (as a proxy of the CoM), and feet, while they walked on a treadmill in six conditions: control (usual step width), narrow-base, and wide-base, each with and without stochastic EVS (peak amplitude of 5 mA; RMS of ~ 1.2 mA; frequency band from 0 to 25 Hz). Stochastic EVS decreased local dynamic stability irrespective of step width. Foot placement correlated stronger with trunk motion during walking with EVS than without in the control condition. However, residual variance in foot placement was increased when walking with EVS, indicating less precise foot placement. Thus, a vestibular error signal leads to a decrease in gait stability and precision of foot placement, but these effects are not consistently modulated by step width.

Stabilization demands of walking modulate the vestibular contributions to gait.

Stable walking relies critically on motor responses to signals of head motion provided by the vestibular system, which are phase-dependent and modulated differently within each muscle. It is unclear, however, whether these vestibular contributions also vary according to the stability of the walking task. Here we investigate how vestibular signals influence muscles relevant for gait stability (medial gastrocnemius, gluteus medius and erector spinae)-as well as their net effect on ground reaction forces-while humans walked normally, with mediolateral stabilization, wide and narrow steps. We estimated local dynamic stability of trunk kinematics together with coherence of electrical vestibular stimulation (EVS) with muscle activity and mediolateral ground reaction forces. Walking with external stabilization increased local dynamic stability and decreased coherence between EVS and all muscles/forces compared to normal walking. Wide-base walking also decreased vestibulomotor coherence, though local dynamic stability did not differ. Conversely, narrow-base walking increased local dynamic stability, but produced muscle-specific increases and decreases in coherence that resulted in a net increase in vestibulomotor coherence with ground reaction forces. Overall, our results show that while vestibular contributions may vary with gait stability, they more critically depend on the stabilization demands (i.e. control effort) needed to maintain a stable walking pattern.

Head orientation and gait stability in young adults, dancers and older adults.

BACKGROUND: Control of body orientation requires head motion detection by the vestibular system and small changes with respect to the gravitational acceleration vector could cause destabilization. RESEARCH QUESTION: We aimed to compare the effects of different head orientations on gait stability in young adults, dancers and older adults. METHODS: Three groups of 10 subjects were evaluated, the first composed of young adults (aged 18-30 years), the second composed of young healthy dancers under high performance dance training (aged 18-30 years), and the third group composed of community-dwelling older adults (aged 65-80 years). Participants walked on a treadmill at their preferred speed in four distinct head orientation conditions for four minutes each: control (neutral orientation); dynamic yaw (following a target over 45° bilaterally); up (15° neck extension), and down (40° neck flexion). Foot and trunk kinematic data were acquired using a 3D motion capture system and the gait pattern was assessed by basic gait parameters (step length, stride width and corresponding variability) and gait stability (local divergence exponents and margins of stability). Main effects of conditions and groups, as well as their interaction effects, were evaluated by repeated-measures analysis of variance. RESULTS: Interactions of group and head orientation were found for both step length and stride width variability; main effects of head orientation were found for all evaluated parameters and main effects of group were found for step length and its variability and local divergence exponents in all directions. SIGNIFICANCE: As expected, the older adults group showed less stable gait (higher local divergence exponent), the shortest step length and greater step length variability. However, contrary to expectation, the dancers were not more stable. The yaw condition was the most challenging for all groups and the down condition seemed to be least challenging.

Caracterização de pacientes com acidente vascular encefálico em atendimento fisioterapêutico em uma universidade pública / Characterization of patients with encephalic vascular accident in physiotherapeutic care in a public university / Caracterización de pacientes con accidente vascular encefálico en atención fisioterapéutica en una universidad pública

O acidente vascular encefálico (AVE) pode levar a alterações funcionais nas áreas sensitiva, motora, cognitiva e de comunicação. Ocorre através de alterações vasculares do encéfalo, originadas de uma suspensão do fluxo sanguíneo que causa danos celulares irreversíveis, podendo ser dividido em isquêmico ou hemorrágico. O objetivo deste estudo foi identificar o perfil epidemiológico e clínico dos pacientes com acidente vascular encefálico atendidos pela fisioterapia em uma clínica escola de instituição pública na região Centro-Oeste do Brasil. Trata-se de um estudo de corte transversal, descritivo, com abordagem quantitativa. Após aprovação do Comitê de Ética, foram tabulados e analisados os dados dos prontuários, através de um formulário estruturado no programa Excel. Os resultados mostraram que, dos 138 indivíduos, 60,15% eram do sexo masculino, e a idade média foi de 59,53 anos. De acordo com a etiologia, 45,3% sofreram AVE isquêmico; 52,5% possuíam hemiplegia à direita, e 16,55% tiveram múltiplos AVE; 78,98% eram hipertensos; 97,1% utilizavam medicamentos. Em relação ao diagnóstico funcional, a maioria possuía déficit de equilíbrio (39,9%); o objetivo fisioterapêutico mais frequente foi melhorar a amplitude de movimento (96,4%), e a conduta prevalente foi o alongamento (65,9%). Concluiu-se que como a incidência de AVE na população e o desenvolvimento de tecnologias assistivas vêm aumentando a cada dia, menos pacientes morrem por conta do AVE, por isso, faz-se necessário o desenvolvimento de estratégias de prevenção primária, como campanhas educativas, além da prevenção secundária, que por meio da fisioterapia precoce, pode reduzir a proporção de pacientes com incapacidades e melhorar a funcionalidade desses indivíduos.

Stroke can lead to functional changes in the sensory, motor, cognitive and communication areas. It occurs through vascular alterations of the brain originated from a suspension of the blood flow that causes irreversible cellular damages, being able to be divided into ischemic or hemorrhagic. This study aimed to identify the epidemiological and clinical profile of stroke patients cared at physical therapy teams in a public institution school in the Midwest region of Brazil. This is a cross-sectional, descriptive study with a quantitative approach. After approval by the Ethics Committee, the data of the medical records were tabulated and analyzed using a form structured in the Excel program. The results showed that of the 138 individuals, 60.15% were males and the mean age was 59.53 years. According to the etiology, 45.3% suffered from ischemic stroke; 52.5% had right hemiplegia, and 16.55% had multiple strokes; 78.98% were hypertensive; 97.1% used drugs. Regarding the functional diagnosis, most patients had an equilibrium deficit (39.9%); the most frequent physiotherapeutic objective was to improve range of motion (96.4%), and the prevalent conduct was elongation (65.9%). In conclusion, although the incidence of stroke in the population and the development of assistive technologies are increasing each day, fewer patients die due to stroke, therefore, it is necessary to develop primary prevention strategies such as educational campaigns, in addition to of secondary prevention that, through early physiotherapy, can reduce the proportion of patients with disabilities and improve the functionality of these individuals.

El accidente vascular encefálico (AVE) puede llevar a cambios funcionales en las áreas sensitiva, motora, cognitiva y comunicación. Se produce a través de cambios vasculares del encéfalo originado por una suspensión del flujo sanguíneo que causa daños celulares irreversibles, los cuales se dividen en isquémico o hemorrágico. El objetivo de este estudio fue identificar el perfil epidemiológico y clínico de los pacientes con accidente vascular encefálico atendidos por la fisioterapia de institución pública de la región centro-oeste de Brasil. Este es un estudio de corte transversal, descriptivo, cuantitativo. Después de la aprobación del comité de ética, fueron tabulados y analizados los datos de los registros clínicos mediante un formulario en el programa Excel. Los resultados mostraron que, de los 138 individuos, el 60,15% eran del sexo masculino y el promedio de edad fue de 59,53 años. De acuerdo con la etiología, el 45,3% sufrió AVE isquémico; El 52,5% tenía hemiplejía a la derecha, y el 16,55% tuvo múltiples AVE; El 78,98% eran hipertensos; El 97,1% utilizaban medicamentos. En relación al diagnóstico funcional, la mayoría tenía déficit de equilibrio (39,9%); el objetivo fisioterapéutico más frecuente fue mejorar la amplitud de movimiento (96,4%), y la conducta prevalente fue el estiramiento (65,9%). Se concluyó que como la incidencia de AVE en la población y el desarrollo de tecnologías asistidas vienen aumentando cada día, menos pacientes mueren a causa de AVE, por lo que se hace necesario el desarrollo de estrategias de prevención primaria como campañas educativas, además de la prevención secundaria que, por medio de la fisioterapia precoz, puede reducir la proporción de pacientes con discapacidades y mejorar la funcionalidad de estos individuos.

Effects of backpack load and positioning on nonlinear gait features in young adults.

Overloaded backpacks can cause changes in posture and gait dynamic balance. Therefore, the aim of this study was to assess gait regularity and local dynamic stability in young adults as they carried a backpack in different positions, and with different loads. Twenty-one healthy young adults participated in the study, carrying a backpack that was loaded with 10 and 20% of their body weight (BW). The participants walked on a level treadmill at their preferred walking speeds for 4 min under different conditions of backpack load and position (i.e. with backpack positioned back bilaterally, back unilaterally, frontally or without a backpack). Results indicate that backpack load and positioning significantly influence gait stability and regularity, with the exception of the 10% BW bilateral back position. Therefore, the recommended safe load for school-age children and adolescents (10% of BW) should also be considered for young adults. Practitioner summary: Increase in load results in changes in posture, muscle activity and gait parameters, so we investigated the gait adaptations related to regularity and stability. Conditions with high backpack loads significantly influenced gait stability and regularity in a position-dependent manner, except for 10% body weight bilateral back position.

Effects of backpack loads and positions on the variability of gait spatiotemporal parameters in young adults

Abstract Introduction: People carry backpacks of different weight in different positions every day. The effects of backpack wearing under different loads and positions were assessed according to the gait's spatiotemporal parameters and their variability in young adults. Methods Twenty-one subjects performed trials of 4 min in the conditions: control condition with no backpack; bilateral back load consisting of 10% body weight (BW); bilateral back load of 20% BW (B20); unilateral load of 10% BW; unilateral load with 20% BW (U20); bilateral frontal load with 10% BW; bilateral frontal load with 20% BW. Results Step length (SL) and step frequency (SF) show that frontal conditions differed from others as seen in B20. Gait cycle phases showed an increase in the B20 condition for double stance phase and stance phase, swing phase presented reduction in the B20 condition. There were significant main effects in position for SL, SF, and walk ratio, in load only for stride width. The highest variability of spatiotemporal parameters occurred in the U20 condition. All load conditions with 20% BW showed a greater variability when compared to the 10% BW counterpart. Conclusion We concluded that young adults can cope with up to a 15% BW load under a bilateral back position, but in the frontal position not even a 10% BW load was proven to be a safe limit. 20% BW loads should be avoided in any position. These recommendations may assure increased gait stability, decreased trunk forward lean and decreased muscle activation and fatigue reducing back pain occurrence.

Local dynamic stability and gait variability during attentional tasks in young adults.

Cell phone use while walking may be a cognitive distraction and reduce visual and motor attention. Thus, the aim of this study was to verify the effects of attentional dual-tasks while using a cell phone in different conditions. Stability, regularity, and linear variability of trunk kinematics, and gait spatiotemporal parameters in young adults were measured. Twenty young subjects of both genders were asked to walk on a treadmill for 4min under the following conditions: (a) looking forward at a fixed target 2.5m away (walking); (b) talking on a cell phone with unilateral handling (talking); (c) texting messages on a cell phone with unilateral handling (texting); and (d) looking forward at the aforementioned target while listening to music without handling the phone (listening). Local dynamic stability measured in terms of the largest Lyapunov exponent decreased while handling a cell phone (talking and texting). Gait variability and regularity increased when talking on a cell phone, but no variable changed in the listening condition. Under all dual-task conditions, there were significant increases in stride width and its variability. We conclude that young adults who use a cell phone when walking adapt their gait pattern conservatively, which can be because of increased attentional demand during cell phone use.

Linear and Nonlinear Gait Features in Older Adults Walking on Inclined Surfaces at Different Speeds.

This study evaluated linear and nonlinear gait features in healthy older adults walking on inclined surfaces at different speeds. Thirty-seven active older adults (experimental group) and fifty young adults (control group) walked on a treadmill at 100% and ±20% of their preferred walking speed for 4 min under horizontal (0%), upward (UP) (+8%), and downward (DOWN) (-8%) conditions. Linear gait variability was assessed using the average standard deviation of trunk acceleration between strides (VAR). Gait stability was assessed using the margin of stability (MoS). Nonlinear gait features were assessed by using the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS), and sample entropy (SEn), as a measure of regularity. VAR increased for all conditions, but the interaction effects between treadmill inclination and age, and speed and age were higher for young adults. DOWN conditions showed the lowest stability in the medial-lateral MoS, but not in LDS. LDS was smaller in UP conditions. However, there were no effects of age for either MoS or LDS. The values of SEn decreased almost linearly from the DOWN to the UP conditions, with significant interaction effects of age for anterior-posterior SEn. The overall results supported the hypothesis that inclined surfaces modulate nonlinear gait features and alter linear gait variability, particularly in UP conditions, but there were no significant effects of age for active older adults.

Gait stability, variability and complexity on inclined surfaces.

This study evaluated the gait stability, variability, and complexity of healthy young adults on inclined surfaces. A total of 49 individuals walked on a treadmill at their preferred speed for 4min at inclinations of 6%, 8%, and 10% in upward (UP) and downward (DOWN) conditions, and in horizontal (0%) condition. Gait variability was assessed using average standard deviation trunk acceleration between strides (VAR), gait stability was assessed using margin of stability (MoS) and maximum Lyapunov exponent (λs), and gait complexity was assessed using sample entropy (SEn). Trunk variability (VAR) increased in the medial-lateral (ML), anterior-posterior, and vertical directions for all inclined conditions. The SEn values indicated that movement complexity decreased almost linearly from DOWN to UP conditions, reflecting changes in gait pattern with longer and slower steps as inclination increased. The DOWN conditions were associated with the highest variability and lowest stability in the MoS ML, but not in λs. Stability was lower in UP conditions, which exhibited the largest λs values. The overall results support the hypothesis that inclined surfaces decrease gait stability and alter gait variability, particularly in UP conditions.

Análise da ativação neuromuscular do vasto medial oblíquo e vasto lateral com o uso da bandagem funcional / Analysis of neuromuscular activation of the vastus medialis obliquus and vastus lateralis with the use of functional taping

Alterações musculares e anatômicas são em sua maioria responsáveis pela síndrome patelofemoral (SDPF). Sabendo que a musculatura do quadríceps é de grande importância na estabilização da patela, questiona-se como o músculo Vasto Medial Oblíquo (VMO) influencia na estabilizaçãopatelar evitando a SDPF. Muitos pesquisadores tem investigado o uso da bandagem funcional como meio de ativação muscular. Objetivo: O presente estudo teve como objetivo analisar o uso da bandagem como meio de ativação do VMO no exercício de agachamento. Método: A atividade dos músculos VMO e Vasto lateral (VL) foi avaliada através de eletromiografia durante o agachamento com adução e o agachamento com o uso de bandagem. A amostra composta por 39 indivíduos foi dividida em quatro grupos: indivíduos do sexo masculino sedentários e atletas, eindivíduos do sexo feminino sedentárias e atletas. Resultados: Embora tenha sido encontrada uma maior ativação do VMO em relação ao VL, com a presente metodologia e variáveis estudadas, não foi possível demonstrar diferença estatística entre os grupos nos agachamentos com e sem o uso da bandagem. No entanto, é importante ressaltar que a ausência de diferença na ativação do VMO durante o agachamento com adução e com bandagem sugerem um efeito positivo e facilitador da bandagem na ativação muscular. Este resultado é muito importante no tratamento de lesões agudas onde o movimento ativo está limitado. Conclusão: Sugere-se a execução de novos estudos aonde outros parâmetros da eletromiografia e estimulação reflexa sejam abordados, a fim de investigar o real papel da bandagem funcional na ativação muscular.

Muscular and anatomical changes are mostly responsible for patella femoral syndrome (PFPS). Knowing that the quadriceps muscles are very important in stabilizing the patella, studies have questioned the influence of the Vastus Medialis Obliquus (VMO) in the patellar stabilization avoiding the PFPS. Many researchers have investigated the use of taping as a means of muscleactivation. Objective: The present study aimed to analyze the use of functional taping to activate the VMO during the squat exercise. Method: The activity of the VMO and Vastus Lateralis (VL) was assessed by electromyography during squats and squats with adduction using functional taping. The sample, composed of 39 individuals, was divided into four groups: males and females, both separated into sedentary and athletic types. Results: Although greater activation of the VMO has been found in comparison with the VL, with the applied methodology and variables, we could not demonstrate a statistical difference between groups in squats with and without the use of functional taping. However, it is important to emphasize that the lack of difference in the activation of VMO during squats with adduction and taping suggests a positive effect of the taping in muscleactivation. This result is very important in the treatment of acute injuries where active movement is limited. Conclusion: Future studies should be done with other electromyography parameters and reflex activation in order to investigate the actual role of functional taping in muscle activation.

Estudo comparativo da atividade do sistema nervoso autônomo através da variabilidade da frequencia cardíaca em trabalhadores noturnos e diurnos / Comparartive study of the independent nervous system activity through the heart rate variability in nocturnal and diurnal workers

O estudo tem como objetivo comparar as alterações físicas entre os trabalhadores diurnos e noturnos. A alteração avaliada foi a variabilidade da frequência cardíaca através do Nerve Express. Também avaliamos a qualidade de vida dos indivíduos através de questionários respondidos antes dos testes. Mensuramos o quanto a ausência do sono noturno influencia na qualidade de vida das pessoas. Percebemos que os indivíduos trabalhadores do período noturno apresentaram melhores resultados quando avaliados em relação à variabilidade da frequência cardíaca, apesar de nos questionários demonstrarem uma maior insatisfação com a qualdiade do sono. Já quando questionados em relação à qualidade de vida ambos os grupos demonstram em sua maioria estarem satisfeitos. Acreditamos que os resultados possuem relação direta com o fato de não possuírem a presença direta de seus superiores.

The study has as objective to compare the physical alterations between the diurnal and nocturnal workers. the alteration evaluated ws the heart variability through nerve express. We also evaluated the quality of life of the individuals through questionnaires answered before the tests. We were able to measure how much the absence of nocturnal sleep influences in the quality of life of life of the people. We realized that the industrious individuals of the nocturnal period presented better results when evaluated regarding the heart variability, despite of in the questionnaires they showed a bigger dissatisfaction with the quality of the sleep. When they were questioned regarding the quality of life, both groups showed, in their majority is satisfied. We believe that the results have straight relation with the fact of the nocturnal workers work in a rhythm less accelerated than the diurnal one, by be not commercial schedule and of not have the straight presence of his superiors.

Software para extração de dados e análise estabilométrica / Software for data extration and stabilometric analysis

Vários sistemas baseados em plataformas de força são utilizados para medição e análise do equilíbrio. Estes sistemas geram uma grande quantidade de dados provenientes dos sensores dos equipamentos que os compõem. Devido aos formatos utilizados para gravação dos resultados obtidos no Footwork e a quantidade de dados gerados em ambos os sistemas, existe a dificuldade de utilização destes dados fora do sistema que os originou. Este estudo teve como objetivo, desenvolver um software para auxiliar na análise mais apurada dos dados de dois sistemas utilizados no Brasil, a fim de automatizar a extração das informações destes sistemas e realizar os cálculos necessários para a avaliação da estabilometria. O software foi concluído com êxito e os resultados obtidos foram excelentes, tornando o trabalho de análise de dados muito mais rápido e preciso.

Several systems based on force plate are used for equilibrium measurement and analysis. These systems generate a huge quantity of date received from the sensors of the pieces of equipment that compose the systems. Due to the formats used for saving the results obtained on the Footwork, and the quantity of data generated in both systems, it is difficult to use these data outside the system that generates them. The objective of this study was the development of software that helps to do a more accurate analysis of data from two systems used in Brazil, in order to make an automatic data retrieval from these systems and perform the calculations necessary for stabilometry analysis. The software was successfully concluded and provided excellent results, redering the data analysis work faster and more accurate.

Pressão plantar dos jogadores de futebol profissional da Associação Atlética Caldense / Plantar pressure of the professional soccer players of the Associação Atlética Caldense

O futebol é uma das modalidades mais praticadas no mundo e a cada dia vem aumentando significativamente seu número de adeptos. O presente estudo tem como objetivo avaliar a distribuição da pressão plantar dos jogadores de futebol profissional da Associação Atlética Caldense, por meio da baropodometria computadorizada e comparar a caracterização da distribuição com a faixa etária e tempo de prática desportiva dos atletas. Foi utilizada uma amostra de vinte e seis jogadores com idade entre 16 a 31 anos, e todos estes em períodos de treinamento e campeonato. A pressão plantar foi analisada em regiões de antepé, mediopé e retropé, onde os resultados obtidos sugerem que a tendência da distribuição de pressão plantar dos atletas de futebol profissional é maior em antepé e não está relacionada com a idade e tempo de prática.

The soccer is one of sportive modalities more played in the world and each day it's adepts is growing significantly. This study has as objective assessment the plantar pressure distribution of professional soccer players of Associação Atlética Caldense, by computerized baropodometry and compare it's characterization with the age and sport practical time. It was used a twenty six players with age between 16 and 31 years, and all of them were in training and champion periods. The pressure plantar was analyzed between the foward, median e back foot, where the results suggest an forward pressure plantar tendence of professional soccer players and this tendency is not related to age and sport practical time.