Transcranial direct current stimulation suggests not improving postural control during adapted tandem position in people with Parkinson's disease: A pilot study.

BACKGROUND: Balance impairments in people with Parkinson's disease (PD) demonstrated mainly in challenging postural tasks, such as increased body oscillation may be attributed to the deficits in the brain structures functionality involved in postural control (e.g., motor cortex, midbrain, and brainstem). Although promising results, the effect of transcranial direct current stimulation (tDCS) on postural control in people with PD is unclear, especially in objective measures such as the center of pressure (CoP) parameters. Thus, we analyzed the effects of a single session of tDCS on the CoP parameters during the adapted tandem position in people with PD. METHODS: Nineteen people with PD participated in this crossover, randomized, and double-blind study. Anodal tDCS was applied over the primary motor cortex in two conditions of stimulation (2 mA/active and sham) on two different days for 20 min immediately before the postural control evaluation. Participants remained standing in an adapted tandem position for the postural control assessment for 30 s (three trials). CoP parameters were acquired by a force plate. RESULTS: No significant differences were demonstrated between stimulation conditions (p-value range = 0.15-0.89). CONCLUSIONS: Our results suggested that a single session of tDCS with 2 mA does not improve the postural control of people with PD during adapted tandem.

Transcranial direct current stimulation for balance rehabilitation in neurological disorders: A systematic review and meta-analysis.

Postural instability is common in neurological diseases. Although transcranial direct current stimulation (tDCS) seems to be a promising complementary therapy, emerging evidence indicates mixed results and protocols' characteristics. We conducted a systematic review and meta-analysis on PubMed, EMBASE, Scopus, and Web of Science to synthesize key findings of the effectiveness of single and multiple sessions of tDCS alone and combined with other interventions on balance in adults with neurological disorders. Thirty-seven studies were included in the systematic review and 33 in the meta-analysis. The reviewed studies did not personalize the stimulation protocol to individual needs/characteristics. A random-effects meta-analysis indicated that tDCS alone (SMD = -0.44; 95%CI = -0.69/-0.19; p < 0.001) and combined with another intervention (SMD = -0.31; 95%CI = -0.51/-0.11; p = 0.002) improved balance in adults with neurological disorders (small to moderate effect sizes). Balance improvements were evidenced regardless of the number of sessions and targeted area. In summary, tDCS is a promising therapy for balance rehabilitation in adults with neurological disorders. However, further clinical trials should identify factors that influence responsiveness to tDCS for a more tailored approach, which may optimize the clinical use of tDCS.

Cumulative additional information does not improve the neuromuscular control during postural responses to perturbations in postural instability/gait disorders subtype of Parkinson's disease.

BACKGROUND: Postural response impairments in postural instability and gait disorders (PIGD) subtype patients may be attributed to Parkinson's disease (PD)-deterioration in central-set (programing/modulating of central outputs during motor responses). Although additional information improves some PD motor impairments, an unanswered question is whether additional information can benefit postural response in PIGD subtype. OBJECTIVE: To analyze the effect of cumulative additional information on postural responses after perturbation in PIGD and neurologically healthy older adults (CG). METHODS: Perturbations were applied in 16 PIGD and 19 CG by the support-base translation. Participants performed 3 blocks of 5 trials without additional information (B1-B3, Day 1) and 5 trials of each cumulative additional information (C1-C4, Day 2): information about perturbation (C1), visual (C2), verbal (C3), and somatosensory information (C4). Electromyography and center of pressure (CoP) parameters were analyzed by ANOVAs with Group (PIGD × CG) and Block (B1 × B2 × B3) and with Group (PIGD × CG) and Condition (B3 × C1 × C2 × C3 × C4). RESULTS: PIGD decreased the range of CoP in B3 while CG decreased both range of CoP and the integral of antagonist's muscle activity (iEMG) in B2. Also, PIGD decreased the recovery time in C4 while CG increased the iEMG of agonist's muscle in C2 and antagonist's muscle in all conditions except C2. CONCLUSION: Additional information provided before postural control assessment influences the postural response in PIGD and CG differently. PIGD demonstrated inflexibility of central-set in modulating the neuromuscular control regardless of additional information. CG presents a flexible system evidenced by the increase of agonist muscle iEMG when provided visual information.

Does the impaired postural control in Parkinson's disease affect the habituation to non-sequential external perturbation trials?

BACKGROUND: How people with Parkinson's disease habituate their postural response to unpredictable translation perturbation is not totally understood. We compared the capacity to change the postural responses after unexpected external perturbation and investigated the habituation plateaus of postural responses to non-sequential perturbation trials in people with Parkinson's disease and healthy older adults. METHODS: In people with Parkinson's disease (n = 37) and older adults (n = 20), sudden posterior support-surface translational were applied in 7 out of 17 randomized trials to ensure perturbation unpredictability. Electromyography and center of pressure parameters of postural response were analyzed by ANOVAs (Group vs. Trials). Two simple planned contrasts were performed to determine at which trial the responses first significantly habituate, and by which trials the habituation plateaus. FINDINGS: Older adults demonstrated a first response change in trial 5 and habituation plateaus after trial 4, while for people with Parkinson's disease, the first change occurred in trial 2 and habituation plateau after trial 5 observed by center of pressure range. People with Parkinson's disease demonstrated a greater center of pressure range in trial 1 compared to older adults. Independent of trial, people with Parkinson's disease vs. older adults demonstrated a greater ankle muscle co-activation and recovery time. INTERPRETATION: Despite the greater center of pressure range in the first trial, people with Parkinson's disease can habituate to unpredictable perturbations. This is reflected by little, to no difference in the time-course of adaptation for all but 2 parameters that showed only marginal differences between people with Parkinson's disease and older adults.

Center of pressure responses to unpredictable external perturbations indicate low accuracy in predicting fall risk in people with Parkinson's disease.

Falls are associated with impairment in postural control in people with Parkinson's disease (PwPD). We aimed to predict the fall risk through models combining postural responses with clinical and cognitive measures. Also, we compared the center of pressure (CoP) between PwPD fallers and non-fallers after unpredictable external perturbations. We expected that CoP parameters combined with clinical and cognitive measures would predict fall risk. Seventy-five individuals participated in the study. CoP parameters were measured during postural responses through five trials with unpredictable translations of the support-surface in posterior direction. Range and peak of CoP were analyzed in two periods: early and late responses. Time to peak (negative peak) and recovery time were analyzed regardless of the periods. Models included the CoP parameters in early (model 1), late responses (model 2), and temporal parameters (model 3). Clinical and cognitive measures were entered into all models. Twenty-nine participants fell at least once, and 46 PwPD did not fall during 12 months following the postural assessment. Range of CoP in late responses was associated with fall risk (p = .046). However, although statistically non-significant, this parameter indicated low accuracy in predicting fall risk (area under the curve = 0.58). Fallers presented a higher range of CoP in early responses than non-fallers (p = .033). In conclusion, although an association was observed between fall risk and range of CoP in late responses, this parameter indicated low accuracy in predicting fall risk in PwPD. Also, fallers demonstrate worse postural control during early responses after external perturbations than non-fallers, measured by CoP parameters.

Double obstacles increase gait asymmetry during obstacle crossing in people with Parkinson's disease and healthy older adults: A pilot study.

Gait asymmetry during unobstructed walking in people with Parkinson's disease (PD) has been well documented. However, under complex situations, such as environments with double obstacles, gait asymmetry remains poorly understood in PD. Therefore, the aim of this study was to analyze inter-limb asymmetry while crossing a single obstacle and double obstacles (with different distances between them) in people with PD and healthy older adults. Nineteen people with PD and 19 healthy older people performed three conditions: (i) walking with one obstacle (Single); (ii) walking with two obstacles with a 50 cm distance between them (Double-50); (iii) walking with two obstacles with a 108 cm distance between them (Double-108). The participants performed the obstacle crossing with both lower limbs. Asymmetry Index was calculated. We found that people with PD presented higher leading and trailing toe clearance asymmetry than healthy older people. In addition, participants increased asymmetry in the Double-50 compared to Single condition. It can be concluded that people with PD show higher asymmetry during obstacle crossing compared to healthy older people, independently of the number of obstacles. In addition, a challenging environment induces asymmetry during obstacle crossing in both people with PD and healthy older people.

Postural adjustments of active youths in perturbation and dual-task conditions / Ajustes posturais de jovens ativos em condições de perturbação e tarefa dupla / Ajustes posturales de jóvenes activos en condiciones de perturbación y doble tarea

ABSTRACT Introduction Cognitive components are necessary to maintain posture during external perturbations. However, few studies have investigated postural control when external perturbations are associated with a concomitant cognitive task (DT). Objectives To analyze the behavior of reactive adjustments after perturbation with different intensities and displacements in active young adults; and to analyze the influence of DT on predictive and reactive adjustments in different perturbation conditions. Methods Twenty-eight physically active young adults stood on an item of equipment that produced displacements of the base. Four experimental conditions were introduced in a single task (ST) and DT (cognitive-report how many times a pre-established number appeared in the audio): 1 (5 cm and 10 cm/s); 2 (5 cm and 25 cm/s); 3 (12 cm and 10 cm/s) and 4 (12 cm and 25 cm/s). Three attempts were carried out for each condition (total=24). Center of pressure (CoP) parameters were analyzed considering the following windows: predictive (-250 to +50 ms), reactive 1 (+50 to +200 ms) and reactive 2 (+200 to +700 ms), in comparison to the start of the CoP activity. One-way ANOVAs were performed to analyze predictive adjustments, while two-way ANOVAs with factor for task (STxDT) and condition (1x2x3x4), with repeated measurements, were performed for the reactive adjustments. Results One-way ANOVA (predictive) indicated that the subjects had higher CoP parameters in ST vs DT. In reactive adjustments 1 and 2, ANOVA indicated greater CoP parameters in condition 2 and 4 when compared to 1 and 3, and in the ST vs DT. The subjects took longer to recover stable position in conditions 1 and 3 than in conditions 2 and 4. Conclusion Perturbation intensity has a greater influence on postural adjustments to maintain balance than on magnitude. Moreover, the association of cognitive tasks with external perturbation decreases CoP oscillation. Therefore, cognitive resources play an important role in postural control after perturbation. Level of evidence III; Study of nonconsecutive patients, with no "gold" standard applied uniformly.

RESUMO Introdução Componentes cognitivos são necessários para manter a postura nas perturbações externas. Porém, poucos estudos investigaram o controle postural quando perturbações externas são associadas à tarefa cognitiva concomitante (TD). Objetivo Analisar o comportamento dos ajustes reativos após perturbação com diferentes intensidades e deslocamentos em adultos jovens ativos; e analisar a influência da TD nos ajustes preditivos e reativos em diferentes condições de perturbação. Métodos Permaneceram em pé sobre um equipamento que provocou deslocamento da base de suporte 28 adultos jovens fisicamente ativos. Quatro condições experimentais foram realizadas em tarefa simples (TS) e TD (cognitiva-reportar quantas vezes um número preestabelecido apareceu no áudio): uma (5cm e 10cm/s); duas (5cm e 25cm/s); três (12cm e 10cm/s) e quatro (12cm e 25cm/s). Foram realizadas três tentativas para cada condição (total=24). Os parâmetros do centro de pressão (CoP) foram analisados em janelamentos: preditivo (-250 a +50ms), reativo 1 (+50 a +200ms) e reativo 2 (+200 a +700ms), em relação ao início da atividade do CoP. ANOVAs one-way foram realizadas para análise dos ajustes preditivos. Já para os ajustes reativos, foram realizadas ANOVAs two-way com fator para tarefa (TS×TD) e condição (1×2×3×4) com medidas repetidas. Resultados ANOVA one-way (preditivo) apontou que os indivíduos apresentaram maiores parâmetros do CoP na TS em relação à TD. Nos reativos 1 e 2, a ANOVA apontou maiores parâmetros do CoP na segunda e na quarta condição quando comparada à primeira e à terceira, e na TS em relação às TD. Apresentaram maior tempo para recuperar a posição estável na primeira e na terceira condição em comparação à segunda e à quarta. Conclusão A intensidade da perturbação influencia mais nos ajustes posturais para manutenção do equilíbrio do que a magnitude. Ainda, as tarefas cognitivas concomitantes à perturbação externa diminuem a oscilação do CoP. Com isso, recursos cognitivos possuem relevância no controle postural após perturbação. Nível de evidência III; Estudos de pacientes não consecutivos, sem padrão de referência "ouro" aplicado uniformemente.

RESUMEN Introducción Los componentes cognitivos son necesarios para mantener la postura en perturbaciones externas. Sin embargo, pocos estudios investigaron el control postural cuando son asociadas perturbaciones a la tarea cognitiva concomitante (TD). Objetivo Analizar el comportamiento de los ajustes reactivos después de una perturbación con diferentes intensidades y desplazamientos en adultos jóvenes activos; y analizar la influencia de la TD en ajustes predictivos y reactivos en diferentes condiciones de perturbación. Métodos Veintiocho adultos jóvenes físicamente activos permanecieron en pie sobre un equipo que provocó desplazamiento de la base de soporte. Cuatro condiciones experimentales fueron realizadas en tareas simples (TS) y TD (cognitiva-reportar cuántas veces un número preestablecido apareció en el audio): una (5 cm y 10 cm/s); dos (5 cm y 25 cm/s); tres (12 cm y 10 cm/s) y cuatro (12 cm y 25 cm/s). Fueron realizadas tres tentativas para cada condición (total=24). Los parámetros del centro de presión (CoP) fueron analizados en ventanas: predictiva (-250 a +50 ms), reactiva 1 (+50 a +200 ms) y reactiva 2 (+200 a +700 ms) en relación al inicio de la actividad del CoP. Fueron realizadas ANOVAs one-way para análisis de los ajustes predictivos. Fueron realizadas ANOVAs two-way con factor para tarea (TSxTD) y condición (1x2x3x4) con medidas repetidas para análisis de los ajustes reactivos. Resultados ANOVA one-way (predictivo) mostró que los individuos presentaron parámetros mayores de CoP en TS con relación a TD. En los reactivos 1 y 2, ANOVA mostró parámetros del CoP en la segunda y cuarta condición cuando comparada a la primera y la tercera, y en la TS con relación a las TD. Presentaron tiempo mayor para recuperar la posición estable en la primera y tercera condición en comparación a la segunda y la cuarta. Conclusión La intensidad de perturbación influencia más en los ajustes posturales para mantenimiento del equilibrio que la magnitud. Además, las tareas cognitivas concomitantes a la perturbación externa disminuyen la oscilación del CoP. Con eso, los recursos cognitivos poseen relevancia en el control postural después de la perturbación. Nivel de evidencia III; Estudios de pacientes no consecutivos, sin estándar de referencia "oro" aplicado uniformemente.

Author Correction: Variability of crossing phase in older people with Parkinson's disease is dependent of obstacle height.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Postural control after unexpected external perturbation: Effects of Parkinson's disease subtype.

Different clinical subtypes of Parkinson's disease (PD) have long been recognized. Recent studies have focused on two PD subtypes: Postural Instability and Gait Difficulty (PIGD) and Tremor Dominant (TD). PIGD patients have greater difficulties in postural control in relation to TD. However, knowledge about the differences in reactive adjustment mechanisms following a perturbation in TD and PIGD is limited. This study aimed to compare reactive postural adjustments under unexpected external perturbation in TD, PIGD, and control group (CG) subjects. Forty-five individuals (15 TD, 15 PIGD, and 15 CG) participated in this study. Postural perturbation was applied by the posterior displacement of the support surface in an unexpected condition. The velocity (15 cm/s) and displacement (5 cm/s) of perturbation were the same for all participants. Center of pressure (CoP) and center of mass (CoM) were analyzed for two reactive windows after the perturbation (0-200 ms and 200-700 ms). The Bonferroni post hoc test indicated a higher range of CoP in the PIGD when compared to the CG (p = 0.021). The PIGD demonstrated greater time to recover the stable posture compared to the TD (p = 0.017) and CG (p = 0.003). Furthermore, the TD showed higher AP-acceleration peak of CoM when compared to the PIGD (p = 0.048) and CG (p = 0.013), and greater AP-acceleration range of CoM in relation to the CG (p = 0.022). These findings suggest that PD patients present worse reactive postural control after perturbation compared to healthy older individuals. CoP and CoM parameters are sensitive to understand and detect the differences in reactive postural mechanisms in PD subtypes.

Variability of crossing phase in older people with Parkinson's disease is dependent of obstacle height.

Our aim was investigating variability in spatiotemporal parameters and kinetics of obstacle avoidance steps of different height obstacles in people with Parkinson's disease (PD) and healthy older people. Twenty-eight participants have included (15 PD - stage disease: 2.1 ± 0.4 pts) and 13 healthy older people (control group). Each subject performed 10 trials of the following tasks: low obstacle, intermediate obstacle and high obstacle. The presentation order was randomized by block for each condition and participant. The spatiotemporal parameters was collected by GAITRite. An optoelectronic system (Optotrak Northern Digital Inc.) with 100 Hz of frequency was used to collect obstacle parameters. The kinect parameters (propulsion impulse and braking impulse) were acquire through two force plates (AccuGait), with a frequency of acquisition 200 Hz. Intersteps variability was calculated throughout mean values, standard deviation and coefficient of variation of two obstacle avoidance steps for each trial. PD group presented greater variability than control group on vertical and horizontal distances to the obstacle. Obstacle height did not change kinect's parameters for both groups. The combination of task complexity (obstacle height) and disease impairments (gait alteration, loss of balance, etc) contributing for greater variability of Parkinson's group. Besides, low obstacle and high obstacle seem to exacerbate variability of distance between obstacle and foot.

Obstacle Avoidance Increases Asymmetry of Crossing Step in Individuals With Parkinson's Disease and Neurologically Healthy Individuals.

The authors' aim was to investigate gait asymmetry of crossing step during obstacle avoidance while walking in people with Parkinson's disease (PD) under and without the effects of dopaminergic medication. Thirteen individuals with PD and 13 neurologically healthy individuals performed 5 trials of unobstructed gait and 10 trials of obstacle crossing during gait (5 trials with each leg) and spatiotemporal parameters were analyzed. Obstacle crossing increased step duration of the crossing step for the most-affected or nondominant limb compared to the crossing step with the least-affected or dominant limb. Individuals with PD without the effects of medication increased step duration for the step with the least-affected limb compared to the step with the most-affected limb during obstacle crossing.

A program of physical activity improves gait impairment in people with Alzheimer's disease

AIM: This study aimed to identify the effects of aging and Alzheimer's disease (AD) on gait parameters after a four-month period and to investigate the effects of a four-month program of physical activity, with emphasis on the cognitive components of gait during single and dual task, in people with AD. METHODS: Twenty-three people with AD, divided into the Training Group (TG; n=12; aged 79.17±7.62 years) and the Control Group (CG; n=11; aged 77.00±5.57 years), and eleven healthy older adults (Healthy Group - HG; aged 75.82±4.83 years) were included in this study. TG participated in a physical activity program for four months. The CG and HG were instructed not to participate in any kind of regular physical activity in this period. The physical activity program includes motor activities and cognitive tasks simultaneously. The participants attended a 1-h session three times a week. The kinematic parameters of gait were analyzed under two conditions, before and after a physical activity program: single and dual task. Deltas for all dependent variables between pre and post training were calculated. The deltas were compared using two-way ANOVAs with group (TG x CG and CG x HG) and task (single x dual task) as factors, with repeated measures for task. RESULTS: After the training period, the TG improved stride length, duration, velocity and cadence compared to the CG. CONCLUSION: Physical activity with emphasis on cognitive components promotes better reallocation of attention while walking in people with AD, improving attentional focus on the gait and thus resulting in a safer locomotive pattern.(AU)

The variability of the steps preceding obstacle avoidance (approach phase) is dependent on the height of the obstacle in people with Parkinson's disease.

Gait variability may serve as a sensitive and clinically relevant parameter to quantify adjustments in walking and the changes with aging and neurological disease. Variability of steps preceding obstacle avoidance (approach phase) are important for efficiency in the task, especially in people with Parkinson's disease (PD). However, variability of gait during the approach phase to obstacle avoidance in people with PD has been rarely reported, particularly when ambulating obstacles of different heights. The aim of the present study was to investigate the effects of obstacle height on step-to-step variability (step-to-step variability provides information on the variation between the "equivalent steps" for all trials, and walking variability (indicates the within-step variability of each, providing information about the modulations between the steps performed. of spatial-temporal parameters during the approach phase to obstacle avoidance in people with PD and neurologically healthy older people. Twenty-eight older people; 15 with PD and 13 neurologically healthy individuals (control group), participated in the study. Participants were instructed to walk at their preferred speed until the end of the pathway and to avoid the obstacle when it was present. Each subject performed 10 trials of the following tasks: unobstructed walking, low obstacle avoidance (3cm length, height equal ankle's height, 60 cm wide), intermediate obstacle (3cm length, low plus high obstacle height divided by 2, 60 cm wide) avoidance and high obstacle avoidance (3cm length, knee's height, 60 cm wide). The obstacle was positioned 4m from to the start position. The step-to-step and walking variability of the spatial-temporal parameters (acquiring with GAITRite®) of the four steps before obstacle avoidance were analyzed. MANOVAs were used to compare the data. PD group showed the characteristic gait deficits associated with PD. The obstacle increased the spatial-temporal variability (step-to-step and walking variability) during the approach phase to the obstacle. Specifically, both groups increased i) the step-to- step variability of the step length during low obstacle avoidance when compared to the other conditions; ii) the variability during low obstacle avoidance in the last step before obstacle (n-1) compared to higher obstacle avoidance; iii) variability during higher obstacle avoidance in further steps (n-3 and n-4). In conclusion, the presence of the obstacle during walking increased the variability of spatial-temporal parameters in older people with PD and the control group during the steps preceding obstacle avoidance. In addition motor planning (and motor adaptations) was initiated much earlier in the approach phase for the higher obstacle conditions compared to the low obstacle condition.

Different types of additional somatosensory information do not promote immediate benefits on gait in patients with Parkinson's disease and older adults / Diferentes tipos de informação somatossensorial adicional não promovem benefícios imediatos no andar de pacientes com doença de Parkinson e idosos sadios / Diferentes tipos de información somatosensorial adicional no promueven beneficios inmediatos sobre la marcha en pacientes con enfermedad de Parkinson y los mayores saludables

Plantar cutaneous stimulation has been shown to improve gait in Parkinson's disease (PD), but the effects of different types of insoles have not been tested. We evaluated the immediate effect of different types of insoles on gait in PD patients and healthy older adults. Nineteen PD patients and nineteen healthy older adults performed and performed a walking task at their self-selected speed in three conditions: conventional insole, insole with a raised ridge around the foot perimeter, and insole with half-spheres. Plantar sensation was evaluated before and after the walking protocol. There were no differences between groups for plantar sensation before and after the walking task. PD patients demonstrated reduced stride length and stride velocity. There were no immediate benefits offered by the insoles on gait of either group. The increased plantar cutaneous stimulation does not promote immediate benefits on gait in PD patients and healthy older adults.

A estimulação cutânea plantar beneficia o andar de pacientes com doença de Parkinson (DP), mas os efeitos de diferentes tipos de palmilhas ainda não foram testados. Nós avaliamos o efeito imediato de diferentes tipos de palmilhas no andar de pacientes com DP e idosos saudáveis. Dezenove pacientes com DP e dezenove idosos sadios andaram em três condições: palmilha convencional, palmilha com borda na parte externa da superfície do pé e palmilha com semi-esferas. A sensibilidade plantar foi avaliada antes e após o protocolo do andar. Não foram encontradas diferenças entre os grupos para sensibilidade plantar antes e após a tarefa do andar. Os pacientes apresentaram reduzida velocidade e menor comprimento da passada. Não foram verificados benefícios imediatos das palmilhas no andar para os grupos. O aumento na estimulação cutânea plantar não promoveu benefícios imediatos no andar de pacientes com DP e controles.

La estimulación plantar beneficia el andar e de pacientes con enfermedad de Parkinson-(EP), pero los efectos de diferentes tipos de plantillas no fueron testados. Evaluamos el efecto inmediato de diferentes tipos de plantillas en el andar de pacientes con EP y en mayores saludables. Diecinueve pacientes con EP y diecinueve controles fueron evaluados en el andar en tres condiciones: plantilla convencional, plantilla con borde en la superficie exterior del pie e plantilla con semi-esferas. La sensibilidad plantar fue evaluada antes y después de lo andar. No hubo diferencias entre los grupos para la sensibilidad plantar antes y después de lo andar. Los pacientes mostraron velocidad reducida y menor longitud de la zancada. No hubo beneficios inmediatos de las plantillas en el andar para los grupos. El aumento en la estimulación plantar no promovió beneficios inmediatos en el andar para los grupos.

Efeitos do exercicio agudo sobre biomarcadores sericos de ratos diabeticos / The effects of acute exercise on serum biomarkers in diabetics rats / Efectos del ejercicio agudo sobre biomarcadores de suero em ratones diabeticos

INTRODUÇÃO: As respostas ao exercício agudo dos biomarcadores, como a fosfatase alcalina (FA) e a creatina quinase (CK) séricas têm sido pouco investigadas em ratos diabéticos. OBJETIVOS: Verificar os efeitos do exercício físico aeróbio agudo sobre as concentrações de CK e FA, bem como, avaliar o estado hídrico em ratos diabéticos experimentais. MATERIAIS E MÉTODOS Foram utilizados ratos Wistar machos, adultos jovens, distribuídos em dois grupos: diabéticos (DA) e controles (CA). O diabetes foi induzido por meio da administração de aloxana monoidratado Sigma(r) (32 mg/kg de peso corporal). Duas semanas após confirmação do diabetes, ambos os grupos foram submetidos a uma sessão aguda de natação por 30 min, com carga aeróbia (4,5 % do peso corporal). Foram avaliados: glicose, hematócrito, CK, FA, albumina e a cinética de lactato durante o exercício por meio de coletas 25 µL de sangue da cauda dos animais, nos minutos 0, 10, 20 e 30 de exercício. RESULTADOS: ANOVA de dois fatores para medidas repetidas e o teste post hoc de Tukey apontaram diminuição significativa dos valores de glicemia após o exercício para o grupo DA, aumento significativo de CK pós-exercício para o grupo DA, aumento significativo de hematócrito para ambos os grupos após exercício e manutenção da FA após exercício para o grupo DA. CONCLUSÃO: O exercício agudo aeróbio foi eficiente no controle dos níveis glicêmicos de ratos diabéticos. Entretanto, deve ser aplicado com cautela, pois induziu altos valores de CK, sugerindo possíveis lesões teciduais. .

INTRODUCTION: The responses to acute exercise on biomarkers, such as alkaline phosphatase (ALP) and creatine kinase (CK) serum levels have been little investigated in diabetic rats. OBJECTIVES: To investigate the effects of acute aerobic exercise on the concentrations of CK and ALP as well as evaluating the hydration status in diabetic rats. MATERIALS AND METHODS: Were used male Wistar rats, young adults, divided into two groups: diabetic (DA) and controls (CA). The diabetes was induced in the rats by administration of alloxan monohydrate Sigma(r) (32 mg/kg body weight). Two weeks after confirmation of diabetes, both groups were subjected to an acute swim session for 30 min, with aerobic load (4.5% body weight). Glucose, hematocrit, CK, ALP, albumin and lactate kinetics during exercise were evaluated by collecting 25µL of blood from the tail of the animals in minutes 0, 10, 20 and 30 of exercise. RESULTS: Two-way ANOVA for repeated measures and post hoc Tukey test showed significant decrease of glycemia after exercise for the DA group, significant increase in CK after exercise for the DA group, significant increase in hematocrit for both groups after exercise and maintenance of ALP after exercise for the DA group. CONCLUSION: The acute aerobic exercise was effective in controlling glucose levels in diabetic rats. However, it should be applied with caution, because it induced high CK values, suggesting possible tissue damage. .

INTRODUCCIÓN: Las respuestas al ejercicio agudo de los biomarcadores, como la fosfatasa alcalina (FA) y la creatina quinasa (CK) séricas han sido poco investigadas en ratones diabéticos. OBJETIVOS: Verificar los efectos del ejercicio físico aeróbico agudo sobre las concentraciones de CK y FA, bien como evaluar el estado hídrico en ratones diabéticos experimentales. MATERIALES Y MÉTODOS: Fueron utilizados ratones Wistar machos, adultos jóvenes, distribuidos en dos grupos: diabéticos (DA) y controles (CA). La diabetes fue inducida por medio de la administración de aloxana monohidratado Sigma(r) (32 mg/kg de peso corporal). Dos semanas después de la confirmación de la diabetes, ambos grupos fueron sometidos a una sesión aguda de natación por 30 minutos, con carga aeróbica (4,5% del peso corporal). Fueron evaluados: Glucosa, hematocrito, CK, FA, albumina y La cinética de lactato durante el ejercicio por medio de colectas de 25 µL de sangre de la cola de los animales, en los minutos 0, 10, 20 y 30 de ejercicio. RESULTADOS: ANOVA de dos factores para medidas repetidas y el test post hoc de Tukey apuntaron disminución significativa de los valores de glicemia después del ejercicio para el grupo DA, aumento significativo de CK después del ejercicio para el grupo DA, aumento significativo de hematocrito para ambos grupos después del ejercicio y mantenimiento de la FA después del ejercicio para el grupo DA. CONCLUSIÓN: El ejercicio agudo aeróbico fue eficiente en el control de los niveles glicémicos de ratones diabéticos. Entretanto, debe ser aplicado con cautela, pues indujo altos valores de CK, sugiriendo posibles lesiones tisulares. .

Systematic review of the effects of fatigue on spatiotemporal gait parameters.

PURPOSE: This systematic review aimed to assess changes on spatiotemporal gait parameters due to fatigue. MATERIAL AND METHOD: A search was carried out in literature published from 1950 to December 2010 and retrieved 771 articles using terms referring to walking and fatigue in the title, abstract or keywords. Two researchers assessed the selection and quality of each article independently. RESULTS: Seven studies were selected for this systematic review, two of which reported on the same data set. Several spatiotemporal parameters were reported to change with fatigue, but the few variables studied in multiple studies, gait speed and stride or step length and stride time, were affected only in single studies. Fatigue appears to modulate spatiotemporal gait parameters, but the effects of fatigue appear to be dependent on the muscles that were fatigued, and age that appears to be a moderator of the effects of fatigue on gait.

Revisão sistemática do efeito do envelhecimento no andar livre e adaptativo / Systematic review of the effect of aging on the free and adaptive gait

O envelhecimento parece comprometer o andar dos indivíduos. Entretanto, ainda não é claro quais são os efeitos do envelhecimento no andar. O objetivo deste estudo foi determinar as mudanças nos parâmetros cinemáticos, cinéticos e eletromiográficos do andar livre e adaptativo, em velocidade preferida, causadas pelo envelhecimento. A estratégia de busca inicial foi realizada para identificar os artigos que analisaram o andar livre e adaptativo. Foram utilizadas as bases de dados eletrônicas MEDLINE, PubMed, EMBASE, CINAHL, Sports Discus, DARE, PsychInfo, ERIC, AusportMed, AMI, Cochrane e PEDro. Vinte e três artigos foram revisados na íntegra. Idosos são mais lentos, têm menor comprimento do passo e maior duração de duplo suporte do que adultos jovens durante o andar livre e adaptativo. Ainda, eles apresentaram maiores demandas musculares, ocorrendo redistribuição da potência e do torque articular e aplicação de menor força na fase de propulsão e de absorção da massa corporal. Concluiu-se que idosos modificam os parâmetros cinemáticos, cinéticos e eletromiográficos do andar livre e adaptativo quando comparados a adultos jovens.

Aging seems to impair the walking. However, it is not clear the effects of aging on walking. The aim of this study was to determine changes in kinematic, kinetic and electromyographic parameters of the free and adaptive gait, in preferred velocity, caused by aging. The initial search strategy was performed to identify all articles that examined the free and adaptive gait. The electronic databases analyzed were: MEDLINE, PubMed, EMBASE, CINAHL, Sports Discus, DARE, PsychInfo, ERIC, AusportMed, AMI, Cochrane and PEDro. Twenty-three articles were reviewed in full. Elderly are slower, with shorter step length and longer double support duration than young adults during free and adaptive gait. Even, they showed higher muscular demands, with redistribution of joint power and torque and decreased force in the propulsion and absorption phases. It was concluded that elderly present altered kinematic, kinetic and electromyographic parameters of free and adaptive gait compared to young adults.