Challenging postural tasks increase asymmetry in patients with parkinson's disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Saccadic and smooth pursuit eye movements attenuate postural sway similarly

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A complexidade de tarefas de controle postural afeta a sensibilidade háptica proporcionada pelo toque leve?

A utilização de pistas hápticas para a estabilização da postura através do toque vem sendo apontada como uma eficiente fonte de informação sensorial que conecta o indivíduo ao meio. Dessa forma, o paradigma do toque leve (i.e., tocar uma superfície com força inferior a 1 Newton) é uma das possibilidades de, através do contato com determinada superfície, atenuar as oscilações do indivíduo. Sendo assim, o objetivo deste estudo foi verificar a eficiência do toque leve em tarefas de alta complexidade ao equilíbrio e, concomitantemente, analisar a relação entre percepção háptica e controle da postura. Para isso, 15 adultos jovens saudáveis participaram deste estudo, permanecendo em pé na posição tandem sobre uma plataforma de força e-nas condições pertinentes-sobre uma trave de equilíbrio. As condições deste estudo variaram entre a utilização ou não do toque, a utilização ou não da visão, e ainda, permanecer em pé sobre uma superfície de altura normal (0 cm) ou uma superfície com elevação (20 cm). Através da análise estatística avaliamos as variáveis amplitude média de oscilação (ântero-posterior e mediolateral), velocidade média (ântero-posterior e medio-lateral) e a trajetória total. Nossos resultados demonstraram, como já era esperado, um aumento significativo da oscilação corporal nas condições sem toque e sem a utilização da visão, e ainda maior quando houve elevação da superfície de apoio dos pés. Entretanto, quando o toque leve foi utilizado nessas mesmas condições houve uma redução significativa da oscilação postural dos indivíduos. Dessa forma, concluímos que mesmo em tarefas de alta instabilidade ao equilíbrio, o toque leve continua auxiliando no controle da postura

Assimetria no controle postural em idosos caidores e não caidores neurologicamente sadios e com doenã de Parkinson em diferentes posições estáticas

Individuals with Parkinson's disease (PD) seem to present asymmetric postural control, and the commitment to postural control that is a big factor of falls in this population. However, the asymmetry in the postural control of fallers and non fallers with PD and neurologically healthy elderly is not too much studied. The objective of the study is to analyze the asymmetry in postural control in different static positions of elderly patients with PD and healthy elderly fallers and non fallers. The study included 70 older adults with PD and 70 neurologically healthy (CG). The groups were matched for age, gender, height, weight and cognitive condition. It was evaluated the clinical, cognitive status and incidence of falls among its participants through weekly prospective follow-up of 4 months. Then, for each group, CG and PD, it was selected 12 elderly fallers and 12 elderly non fallers to evaluate postural control. Participants were evaluated through two force platforms in conditions of bipedal support, unipedal and tandem position. It was realized 3 attempts of 30s for each condition. For unipedal and tandem condition it was made 3 attempts for each lower limb. The parameters of interest of the center of pressure (CoP), were analyzed for each condition and compared by MANOVAs with factor group, fall and asymmetry. Post hoc Tukey tests were used to determine the relationships between them. The results show that CG individuals showed greater velocity and CoP area in relation to PD. It was verified that at the control group that non fallers individuals (CGN) had more displacement and RMS in the average lateral direction in the dominant limb when compared to the less affected limb of non fallers with PD (PDN). Faller individuals in the control group (CGF) had larger area in the non dominant limb when compared to the most affected leg of fallers individuals with PD (PDF). Still, the PDF individuals had higher RMS in anteroposterior feeling....

Efeito de tarefa dupla no controle postural de adultos idosos: acoplamento sensório-motor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos de uma tarefa dupla e demandas da tarefa no controle postural de adultos jovens

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reflex postural control of patients with cerebral palsy for odontological assistance

Cerebral palsy (CP) describes a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain.A child with cerebral palsy may have impairments in motor control, which contributes to loss of functional abilities in posture and mobility. The severity of the impairment on the neuromuscular system determines the variations of functional mobility in children with cerebral palsy. The control of the patient, during the dental treatment, is of fundamental importance because these patients present some pathological reflexes which interfere in the odontological assistance

Efeitos da vibração, do plano de oscilação e de uma sessão de uso da haste vibratória sobre o controle postural de mulheres idosas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência de movimentos oculares sacádicos no equilíbrio postural de idosos praticantes de vôlei adaptado e idosos sedentários

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Estabilização postural do olhar: efeitos da distância do objeto

The aim of the present study was to analyze the effects of looking at targets located at different distances on body oscillation during tasks of distinct difficulties. In Experiment 1, ten participants in quiet stance fixated targets in three conditions: No object-far (fixation on far-target without near-target), Object-near (fixation on near target with fartarget), and Object-far (fixation on far-target with near-target). Mean oscillations of trunk in anterior-posterior axis were smallest in the Object-near condition; the No object-far and Object-far conditions were similar. In Experiment 2, seven participants in kiba-dachi, a karate stance, were submitted to three conditions: Blindfolded, No object-far, and Object-near. Mean oscillations of head and trunk in anterior-posterior axis were smaller in the Object-near as compared to blindfolded condition; trunk oscillated more during No object-far than Object-near condition. The results support the notion that a simple posture is not automatically regulated by the optical flow, but different amounts of visual instability may be tolerated according to the fixation distance, regardless the presence of non-fixated objects; the control of a more difficult posture may also accommodate the effects of fixation distance.

Effects of saccadic eye movements on postural control in older adults

Saccadic eye movements have been shown to affect posture by decreasing the magnitude of body sway in young adults. However, there is no evidence of how the search for visual information that occurs during eye movements affects postural control in older adults. The purpose of the present study was to determine the influence of saccadic eye movements on postural control in older adults while they stood on 2 different bases of support. Twelve older adults stood upright in 70-s trials under 2 stance conditions (wide and narrow) and 3 gaze conditions (fixation, saccadic eye movements at 0.5 Hz, and saccadic eye movements at 1.1 Hz). Head and trunk sway amplitude and mean sway frequency were measured in both the anterior/posterior (AP) and medial/lateral (ML) directions. The results showed that the amplitude of body sway was reduced during saccades compared with fixation, as previously observed in young adults. However, older adults exhibited similar sway amplitude and frequency in the AP direction under the wide and narrow stance conditions, which is different from observations in young adults, who display larger sway in a narrow stance compared with a wide stance while performing saccades. These results suggest that although older adults are affected by saccadic eye movements by a decrease in the amplitude of body sway, as observed in young adults, they present a more rigid postural control strategy that does not allow larger sway during a more challenging stance condition.

Visual conditions and postural directions affect postural sway variability in patients with Parkinson’s disease

Postural sway variability was evaluated in Parkinson’s disease (PD) patients at different stages of disease. Twenty PD patients were grouped into two groups (unilateral, 14; bilateral, 6) according to disease severity. The results showed no significant differences in postural sway variability between the groups (p ≥ 0.05). Postural sway variability was higher in the antero-posterior direction and with the eyes closed. Significant differences between the unilateral and bilateral groups were observed in clinical tests (UPDRS, Berg Balance Scale, and retropulsion test; p ≤ 0.05, all). Postural sway variability was unaffected by disease severity, indicating that neurological mechanisms for postural control still function at advanced stages of disease. Postural sway instability appears to occur in the antero-posterior direction to compensate for the stooped posture. The eyes-closed condition during upright stance appears to be challenging for PD patients because of the associated sensory integration deficit. Finally, objective measures such as postural sway variability may be more reliable than clinical tests to evaluate changes in balance control in PD patients.

Efeitos da informação comportamental na dinâmica intrínseca do controle postural

Esse estudo teve como objetivo examinar possíveis alterações na dinâmica intrínseca de crianças e adultos decorrentes de informações externas na realização de uma tarefa de manutenção da postura ereta. Participaram do estudo dez crianças de 8 anos de idade e dez adultos jovens de ambos os gêneros. Eles permaneceram na posição ereta dentro de uma sala móvel que foi movimentada continuamente para frente e para trás. Os participantes recebiam informação sobre o movimento da sala e eram solicitados a não oscilar ou a oscilar junto com o movimento da mesma. Os resultados mostraram que a manipulação da informação visual induziu oscilação corporal correspondente (dinâmica intrínseca) em crianças e adultos. Informação sobre o movimento da sala e solicitação de uma ação (informação comportamental) alteraram o relacionamento entre informação visual e oscilação corporal. Crianças apresentaram mais dificuldades em alterar a dinâmica intrínseca do que adultos, indicando que elas são mais dependentes da dinâmica intrínseca do que adultos. Esses resultados trazem implicações importantes para a situação de ensino-aprendizagem, pois indica que aprendizagem envolvendo crianças deve ser estruturada propiciando condições mais favoráveis para alterações na dinâmica intrínseca para que os objetivos da mesma sejam alcançados.

Imperceptible electrical noise attenuates isometric plantar flexion force fluctuations with correlated reductions in postural sway

Optimal levels of noise stimulation have been shown to enhance the detection and transmission of neural signals thereby improving the performance of sensory and motor systems. The first series of experiments in the present study aimed to investigate whether subsensory electrical noise stimulation applied over the triceps surae (TS) in seated subjects decreases torque variability during a force-matching task of isometric plantar flexion and whether the same electrical noise stimulation decreases postural sway during quiet stance. Correlation tests were applied to investigate whether the noise-induced postural sway decrease is linearly predicted by the noise-induced torque variability decrease. A second series of experiments was conducted to investigate whether there are differences in torque variability between conditions in which the subsensory electrical noise is applied only to the TS, only to the tibialis anterior (TA) and to both TS and TA, during the force-matching task with seated subjects. Noise stimulation applied over the TS muscles caused a significant reduction in force variability during the maintained isometric force paradigm and also decreased postural oscillations during quiet stance. Moreover, there was a significant correlation between the reduction in force fluctuation and the decrease in postural sway with the electrical noise stimulation. This last result indicates that changes in plantar flexion force variability in response to a given subsensory random stimulation of the TS may provide an estimate of the variations in postural sway caused by the same subsensory stimulation of the TS. We suggest that the decreases in force variability and postural sway found here are due to stochastic resonance that causes an improved transmission of proprioceptive information. In the second series of experiments, the reduction in force variability found when noise was applied to the TA muscle alone did not reach statistical significance, suggesting that TS proprioception gives a better feedback to reduce force fluctuation in isometric plantar flexion conditions.

Effectiveness of an exercise program on postural control in frail older adults

Background: Exercise programs have proved to be helpful for frail older adults. This study aimed to investigate the effects of an exercise program with a focus on postural control exercises in frail older adults. Method: Twenty-six older adults (76.7 +/- 4.9 years) deemed clinically stable, chosen from the Falls Unit, University Hospital Mutua Terrassa, Barcelona, Spain, participated in this single-group study. Volunteers' postural control was evaluated using the Timed Up and Go test (TUG) and the Guralnik test battery, and their static and dynamic posturography were evaluated using the Synapsys Posturography System (R). These evaluations were performed before and after the intervention program, which included an educational session and two weekly 1-hour sessions over an 8-week period of stretching exercises, proprioception, balance, and motor coordination. Data were analyzed using the Student's t-test or the Wilcoxon test, with a significance level of 5%. Results: The TUG and Guralnik tests did not show significant differences. Concerning static posturography, there was improvement in the base of support (P = 0.006), anteroposterior displacement with eyes open (P = 0.02) and closed (P = 0.03), and the total amplitude of the center of pressure with eyes closed (P = 0.02). Regarding dynamic posturography, a decrease of the oscillation speed in the anteroposterior direction (P = 0.01) was observed in individuals with their eyes open. Conclusion: The program used in this study was safe and was able to promote some improvement in postural control, especially in the anteroposterior direction and in the base of support. However, it is noteworthy that further improvements could be obtained from a program of longer duration and greater frequency.