The level and completeness of spinal cord injury (SCI) above the first lumbar vertebra determine the degree of multi-system impairments including altered respiratory function and decreased capacity to maintain upright posture and seated postural stability in humans. Both systems were studied in able-bodied (AB) subjects and individuals with tetraplegia to explore the potential of functional electrical stimulation (FES) as a neuroprosthesis for seated postural control without compromising respiratory function. Data for AB participants (n=10) indicated higher tidal volumes, greater trunk extensor muscle activity, and different values of seated postural stability in upright sitting compared to slouch sitting. In three case studies of individuals with tetraplegia, surface FES was applied to trunk muscles. Changes in tidal volume, respiratory rate, and seated postural stability were case specific. These studies inform the development of a strategy for non-invasive FES as a neuroprosthesis for sitting balance while preserving respiratory function in individuals with SCI.

The level and completeness of spinal cord injury (SCI) above the first lumbar vertebra determine the degree of multi-system impairments including altered respiratory function and decreased capacity to maintain upright posture and seated postural stability in humans. Both systems were studied in able-bodied (AB) subjects and individuals with tetraplegia to explore the potential of functional electrical stimulation (FES) as a neuroprosthesis for seated postural control without compromising respiratory function. Data for AB participants (n=10) indicated higher tidal volumes, greater trunk extensor muscle activity, and different values of seated postural stability in upright sitting compared to slouch sitting. In three case studies of individuals with tetraplegia, surface FES was applied to trunk muscles. Changes in tidal volume, respiratory rate, and seated postural stability were case specific. These studies inform the development of a strategy for non-invasive FES as a neuroprosthesis for sitting balance while preserving respiratory function in individuals with SCI.

Objective: To determine the effects of head position and of different postural control demands on head tremor measures in participants with essential tremor. Methods: Seventeen participants with essential tremor (ET) of the head and 17 control participants took part. Individuals held their heads in varying degrees of rotation, flexion, and extension. Subsequently, individuals sat and stood in different postures, incorporating different foot placements (feet apart and together), surfaces (solid and foam), and vision conditions (eyes open and closed). Neck muscle activity was recorded from three muscles bilaterally (trapezius, sternocleidomastoid, splenius capitis). Three-dimensional head and thorax positions were recorded using an Optotrak system, and head angular velocity with respect to thorax was calculated by differentiating tilt-twist angles. Fourier analysis was used to determine tremor power. Results: ET participants showed sharp peaks at their tremor frequency in spectral plots of kinematic data, whereas CN participants did not. Electromyography data was too noisy for frequency analysis. ET participants displayed increased tremor power in head positions 25° from neutral compared to neutral and positions 50° from neutral. Tremor power increased with increasing difficulty of posture for both participant groups. Removal of vision resulted in decreased tremor power in ET participants; power was significantly decreased in the easier postures, and progressively less so with increasing difficulty of posture. Interestingly, tremor direction was inconsistent in both groups, and two ET participants displayed multiple tremor peaks. Conclusions: The tilt-twist method is a feasible way of measuring head kinematics. Changing stiffness of the neck likely mediates the effect of head position on head tremor power, with the resultant interplay of the central driver and the mechanical resonance driving the amplitude changes. Decreasing stability of posture increases head tremor, likely due to the associated increase in postural sway and stress on the postural control system. Vision appears to exacerbate head tremor through the addition of tremor-related visual noise and an implicit task to stabilize vision; this is possible evidence of a visuomotor deficit. However, stabilizing vision becomes less important with increasing difficulty of posture, resulting in a narrowing gap in tremor power between vision and no vision conditions. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2011-03-31 18:16:59.927

Les pertes d’équilibre représentent une cause importante de blessure et de mortalité, notamment sur le milieu du travail et chez les personnes âgées. Cette thèse explore les effets du manque de sommeil sur le contrôle postural en fonction de l’âge et s’intéresse à l’influence des ressources attentionnelles, perceptuelles et motrices sur la relation entre le sommeil et le contrôle postural. Des sujets jeunes et âgés ont effectué diverses tâches posturales statiques sur des plates-formes de force après une nuit de sommeil et après 25 heures de privation de sommeil. L’étendue et la vitesse des déplacements du centre de pression ont été mesurées en gardant les yeux ouverts et les yeux fermés sous trois niveaux de charge cognitive. Les résultats montrent que la privation de sommeil a augmenté l’étendue du centre de pression dans les deux groupes d’âge et a augmenté la vitesse du centre de pression chez les sujets âgés. De plus, les effets de la privation de sommeil sur le contrôle postural étaient davantage prononcés lorsque les sujets âgés gardent les yeux fermés. L’augmentation de la charge cognitive sous privation de sommeil a poussé la majorité des sujets jeunes à adopter un contrôle postural plus statique, alors que chez les sujets âgés, les effets de la charge cognitive ne se surajoutaient pas à ceux de la privation de sommeil. Ces observations suggèrent que la privation de sommeil ait des effets déstabilisateurs sur le contrôle postural qui sont plus marqués chez les personnes âgées, surtout lorsque les informations visuelles sont altérées. Il est donc proposé que le manque de sommeil soit un facteur de risque significatif pour les chutes. / Falls are an important cause of injuries and mortality, especially in the work force and in the elderly population. This thesis investigates the effects of sleep loss on postural control according to age and explores the influence of attentional, perceptual and motor resources on the relationship between sleep and postural control. Young and older participants completed various postural tasks on force plates after a night of sleep and after 25 hours of sleep deprivation. Center of pressure range and velocity were measured with eyes open and with eyes closed while participants performed an interference task, a control task, and no cognitive task. Sleep deprivation increased the range of center of pressure in both age groups and center of pressure speed in older participants only. Moreover, in elderly participants, the destabilizing effects of sleep deprivation were more pronounced with eyes closed. The interference task brought younger participants to adopt a more static postural strategy when sleep deprived. However, in older participant, the interference task did not alter postural control beyond the destabilization induced by sleep loss. These observations suggest that sleep loss has greater destabilizing effects on postural control in older than in younger adults, especially when vision is altered. It is therefore proposed that sleep debt may be a significant risk factor for falls.

This dissertation is composed of three manuscripts based on two studies related to training and assessment methods used to evaluate change and overall quality in measures of performance, postural control, and functional movement. Study one evaluated the effect of sand training on athletic performance and postural control. Study two investigated the effect of scoring strata of the deep squat (DS) component of the Functional Movement Screen (FMS) on the weight-bearing lunge test (WBLT), Star Excursion Balance Test (SEBT), and Lateral Flexion Test (LFT) in 101 male and female college students. Study one results included significant overall improvements of the five repetition maximum (5RM) squat (p=0.002), and WBLT (p Study two results indicated that limited dorsiflexion will lead to a reduction in DS performance and asymmetry of performance on the LFT may result in further movement limitations. Subjects scoring a one or two on the deep squat performed significantly lower (p

Une lésion corticale hémisphérique peut entrainer des troubles distincts en fonction du côté de la lésion : troubles du langage pour l'atteinte de l'hémisphère gauche ou difficultés à tenir debout lorsque c'est l'hémisphère droit qui est atteint. Nous avons fait l'hypothèse que l'hémisphère droit serait associé à une intégration des informations proprioceptives plus pertinente dans le but de contrôler notre posture bipodale. Nous avons donc perturbé ces informations par l'utilisation de vibrations tendineuses et observé les réactions posturales induites pour différents groupes (sujets jeunes, âgés et patients hémiparétiques). Nos résultats démontrent l'utilisation préférentielle de ces informations sensorielles par l'hémisphère droit, dans la gestion et l'organisation posturale au niveau spatial et multi-segmentaire. L'utilisation de ces stimulations proprioceptives pourrait être un facteur important dans la prise en charge thérapeutique de certaines populations pathologiques. / A cortical injury leads to some distinct trouble depending on the injured side; speech and language troubles when the left brain is damaged or standing difficulties when the right brain is injured. Our hypothesis was that the right brain hemisphere permitted a more pertinent integration of proprioceptive information to control the upright position. We perturbed the proprioceptive information with tendon vibration and we observed the induced postural reactions for several groups (young and senior adults, stroke patients). Our results show that proprioceptive information is better processed by the right hemisphere, reflected by control and postural organization at spatial and multi-segmental levels. Proprioceptive stimulations may be an important tool for the rehabilitation of several pathological populations.

Bakgrund: Transfemoralt amputerade har nedsatt balans och ökad fallrisk, men väldigt lite forskning är gjord om detta. Inverted pendulum model (IPM) är en balansmodell för icke-amputerade som bygger på ett känt samband mellan Center of Pressure (CoP) och Center of Mass (CoM). Syftet med denna studie är att kinetiskt validera den inverterade pendelmodellen för transfemoralt amputerade. Metod: I studien deltog amputerade (n=5) och en matchande kontrollgrupp (n=5). Man samlade in data genom att deltagarna fick stå stilla på två stycken kraftplattor under tre styckern villkor; öppna ögon, stängda ögon och weight-bearing feedback. Man undersökte sedan korrelationen mellan avståndet från CoM till CoP och CoMacc i både anterioposterior (A/P) riktning samt medio-lateral (M/L) riktning och analyserade datan med trevägsvariansanalys (ANOVA). Resultat: Resultatet visade att det fanns en signifikant interaktionseffekt mellan villkor och position i M/L-riktning. I A/P-riktning fanns det en signifikant interaktionseffekt mellan grupp och position samt villkor och position. Slutsats: Resultatet innebär att IPM är kinetiskt validerat i A/P-riktning sett till hela kroppen men inte på den amputerade sidan. Hur det intakta benet förhåller sig till IPM för amputerade är tvivelaktigt. / Background: It is known that transfemoral prosthesis users lack normal balance control and are more likely to fall. Research on this topic is insufficient. The Inverted Pendulum Model (IPM) is a commonly used biomechanical model for assessment of balance and postural control for healthy individuals based on an assumption that Center of Pressure (CoP) and Center of Mass (CoM) are inter-dependent. The aim of the study is to validate IPM kinetically for transfemoral prosthesis users. Method: Amputees (n=5) and a control group (n=5) participated. During data collection, participants stood on two force plates with eyes open, eyes closed and with weight-bearing feedback. Correlation of the distance CoP-CoM and CoMacc were calculated for anteroposterior and mediolateral directions and evaluated with three-way ANOVA. Result: Results showed significant interaction effects between condition and position plus group and position in anteroposterior direction and condition and group in mediolateral direction. Conclusion: Results indicate kinetic validity of IPM for transfemoral amputees when looking at the whole body but not at the amputated side in the A/P direction. Kinetic validity of IPM for the intact leg is questionable.

Aim: The aim of this study was to determine the impact of therapy by active videogame Nintendo Wii and by Vojta reflex locomotion on a static and dynamic postural control at a group of children with mild cerebral palsy. Methodology: 14 children (from 6 to 18 years old) were randomly divided into two groups. Both groups received both therapies (active videogame therapy and Vojta reflex locomotion) with a 6 months gap, but in an opposite order. Posturographic measures were obtained before the start of the therapy, after therapy and 8 weeks after the end of the therapy. Results: After both therapies, there was a significant increase in the COP sway velocity in the mCTSIB subtest on a firm surface with closed eyes and the COP sway velocity in the mCTSIB subtest was reduced on a foam surface with closed eyes. Further, after both therapies, there was a significant reduction in the time required to perform the turnabout in SQT test. Other tests (LOS, RWS, WA, TW) and subtests did not change significantly. There was not a significant difference between therapies, but in the post- therapy tests, VRL had a greater tendency to maintain its effect 8 weeks after therapy. Conclusion: Both therapies, Vojta reflex locomotion and active videogame Nintendo Wii, have an influence on a postural control of children...

Orientador: Prof. Dr. Marcos Duarte / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Engenharia Biomédica, 2016. / Alterações associadas ao envelhecimento e algumas doenças podem afetar o controle postural influenciando de maneira negativa a qualidade de vida das pessoas. Há muitos testes que podem ser utilizados para descrever o controle postural do ser humano, entretanto, ainda não há um consenso de quais são os melhores testes a serem empregados durante a avaliação para extrair informações relevantes da condição de equilíbrio do indivíduo. O objetivo deste estudo foi implementar um conjunto de dados público com resultados de avaliações qualitativas e quantitativas relacionadas ao equilíbrio do corpo humano e assim permitir que diferentes centros de pesquisa tenham acesso a dados de referência para comparação e análises em um mesmo conjunto de dados. O controle postural dos sujeitos foi avaliado pela técnica de posturografia utilizando uma plataforma de força e pelo Mini Balance Evaluation Systems Tests. No teste de posturografia, nós avaliamos os sujeitos durante a postura ereta quieta por 60 s em quatro diferentes condições posturais em que a informação visual e de superfície de apoio foram manipuladas: em superfície firme com olhos abertos, em superfície firme com olhos fechados, em superfície macia com olhos abertos, e em superfície macia com olhos fechados. Cada condição postural foi desempenhada três vezes por cada sujeitos e a ordem das condições posturais foi randomizada entre os sujeitos. Em adição, para melhor caracterizar os sujeitos nós empregamos os seguintes testes: Short Falls Efficacy Scale International, Questionário Internacional de Atividade Física ¿ versão curta, e Trail Making Test. Os sujeitos também foram entrevistados para coletar informações referentes às suas características socioculturais, demográficas e de saúde. O conjunto de dados compreende sinais da plataforma de força (dados brutos das forças, dos momentos de força, e dos centros de pressão) de 163 sujeitos e informações sobre os sujeitos, as condições de equilíbrio, e os resultados das demais avaliações. Este estudo está publicado em Santos DA, Duarte M. (2016) A public data set of human balance evaluations. PeerJ Preprints 4:e2162v1 https://doi.org/10.7287/peerj.preprints.2162v1. / Age-related disabilities and certain illnesses affect body balance in humans and can negatively influence their health and quality of life. There is a large variety of tests to describe balance in humans and there is no consensus yet on the best tests and their implementation details in order to extract meaningful information about subject¿s balance condition. The goal of this study was to create a public data set with results of qualitative and quantitative evaluations related to human balance to allow access of a normative reference for data comparison and testing analysis from different centers. Subject¿s balance was evaluated by posturography using a force platform and by the Mini Balance Evaluation Systems Tests. In the posturography test, we evaluated subjects during standing still for 60 s in four different conditions where vision and the standing surface were manipulated: on a rigid surface with eyes open; on a rigid surface with eyes closed; on an unstable surface with eyes open; on an unstable surface with eyes closed. Each condition was performed three times and the order of the conditions was randomized among subjects. In addition, the following tests were employed in order to better characterize each subject: Short Falls Efficacy Scale International; International Physical Activity Questionnaire Short Version; and Trail Making Test. The subjects were also interviewed to collect information about their socio-cultural, demographic, and health characteristics. The data set comprises signals from the force platform (raw data for the force, moments of forces, and centers of pressure) of 163 subjects and information about the subjects and balance conditions and the results of the other evaluations. The results of this study are also published in Santos DA, Duarte M. (2016) A public data set of human balance evaluations. PeerJ Preprints 4:e2162v1 https://doi.org/10.7287/peerj.preprints.2162v1.

Submitted by JULIANA LAHR null (ju_lahr@hotmail.com) on 2016-01-08T17:34:37Z No. of bitstreams: 1 Lahr, Juliana_dissertação.pdf: 4300978 bytes, checksum: c8f51cad4332528f3754c1d768464c48 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-01-11T18:03:07Z (GMT) No. of bitstreams: 1 lahr_j_me_rcla.pdf: 4300978 bytes, checksum: c8f51cad4332528f3754c1d768464c48 (MD5) / Made available in DSpace on 2016-01-11T18:03:07Z (GMT). No. of bitstreams: 1 lahr_j_me_rcla.pdf: 4300978 bytes, checksum: c8f51cad4332528f3754c1d768464c48 (MD5) Previous issue date: 2015-12-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Background: Parkinson’s disease (PD) presents asymmetric early motor symptoms, and those symptoms affect the processing and the integration of proprioceptive information. Due to that, the upper limb motor control is impaired even on single task (isolated manual task) and dual task (manual task and posture control). Because these sort of tasks are performed during activities of daily living, the role of asymmetry on those task must be clarified to elucidate the effects of disease on PD functionality and thus guide the therapists choose more effective interventions. Among strategies of intervention on PD motor impairments, two strategies that deserve special attention are the instruction of external focus of attention and mirror therapy (MT). Both interventions might be potentially effective to facilitate motor learning. Aims: to assess the role of PD asymmetry on upper limbs motor control and postural control in conditions of single versus dual task; and tasks with attentional focus with instructions versus external focus as well as to verify the effect of MT on upper limbs motor control more affected on postural control of PD patients. Methods: Twenty PD patients were submitted to assessments on: Upper Limb motor control (kinematic analysis) and postural control (kinetics analysis), in single and dual task conditions, with and without external focus of attention. Posteriorly, the subjects were distributed in two different groups: GI1 and GI2. The MT protocol consisted in a unilateral home therapy on less affected upper limb, performed 30 minutes a day, five days a week, during 6 consecutives weeks. To assist the subjects of GI1, they performed this protocol using a visual feedback (mirror therapy). Both groups were assessed before and after therapy protocol. Results: performance was not different between upper limbs and single and dual tasks, both in single and in dual task. After protocol period, both groups showed improvements on kinematic outcomes (manual dexterity, movement frequency of the hand, hesitation and task performance time improvements, independent of the sort of focus of attention that was used). Conclusion: Manual task is not affected by PD asymmetry on single and dual task. The external focus of attention was not effective to improve the task performance in PD patients, and it is not recommended to be performed during dynamic tasks. The therapy protocol with or without visual feedback promotes extended benefits on execution and planning of manual task of more affected upper limb independently of focus of attention, but it is not able to decrease the functional and motor impairments neither improve postural control. Therefore MT seems to be equally effective on manual tasks benefits, however more studies are necessary to confirm this efficacy. / Introdução: a doença de Parkinson (DP) tem o início assimétrico dos sintomas motores e afeta o processamento e a integração das informações proprioceptivas, comprometendo o controle motor dos membros superiores tanto em tarefa singular (tarefa manual isolada) quanto em tarefa dupla (tarefa manual e controle postural). Por estas tarefas serem frequentemente exigidas nas atividades de vida diária, esclarecimentos quanto ao papel da assimetria da doença nessas tarefas podem elucidar sobre os efeitos da doença na funcionalidade dos pacientes e nortear a decisão sobre estratégias de intervenção mais pertinentes. Dentre as estratégias de intervenção para esses comprometimentos encontram-se a instrução de foco de ação externo e a terapia do espelho (TE). Ambas as intervenções podem ser potencialmente eficazes na DP por facilitar a aprendizagem motora. Objetivos: avaliar o papel da assimetria da doença no controle dos membros superiores e do controle postural nas condições de tarefa singular versus dupla e de tarefa com instrução de foco de atenção livre versus foco externo, assim como verificar o efeito da TE no controle motor do membro superior afetado e no controle postural de pacientes com DP. Método: 20 pacientes foram avaliados quanto ao controle dos membros superiores (análise cinemática) e ao controle postural (análise cinética), nas condições de tarefa singular e dupla, foco de atenção livre e externo. Posteriormente, os pacientes foram distribuídos nos grupos GI1 e GI2 e realizaram a intervenção que consistiu de treino unilateral do membro superior menos afetado, com duração de 30 minutos diários, 5 dias consecutivos na semana, durante 6 semanas, em domicílio. Na intervenção somente o GI1 utilizou o feedback visual - TE. Os grupos foram avaliados pré- e pós-intervenção. Resultados: o desempenho não diferiu entre os membros superiores e entre as condições de tarefa singular e dupla. O foco de atenção externo reduziu o desempenho da tarefa manual, tanto na tarefa singular quanto na dupla. Após o período de intervenção, ambos os grupos melhoraram o desempenho nas variáveis cinemáticas – aumentaram a destreza manual e a frequência de movimento da mão, diminuíram a hesitação na realização do movimento e o tempo para realizar a tarefa, independente do foco de atenção empregado. Conclusão: a assimetria da doença não interfere no desempenho da tarefa manual nas condições de tarefa singular e dupla. O foco de atenção externo não foi eficaz em melhorar o desempenho da tarefa manual em pacientes com DP, não devendo ser utilizado em tarefas dinâmicas. A intervenção, com ou sem feedback visual, melhora a execução e o planejamento da tarefa manual do membro superior afetado independente do foco atencional empregado, mas não é capaz de reduzir o comprometimento funcional e motor, nem de melhorar o desempenho do controle postural. Portanto, a TE parece ser igualmente eficaz na melhora do desempenho da tarefa manual, porém, mais estudos são necessários para afirmar sua efetividade. / CNPq: 157894/2013-4