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.

tDCS application for postural control in Parkinson's disease: Effects are associated with baseline characteristics.

INTRODUCTION: Transcranial direct current stimulation (tDCS) improves postural response to perturbation in patients with Parkinson's disease (PwPD). However, the influence of baseline characteristics such as clinical/cognitive and postural performance on the response to tDCS remains unclear. OBJECTIVE: To investigate whether baseline level of postural control (performance during sham condition) and clinical/cognitive characteristics are associated with tDCS-related changes in postural responses to external perturbations in PwPD. METHODS: Twenty-four PwPD participated in this study. Clinical assessment included disease severity, disease duration, levodopa equivalent dose and global cognition. Anodal tDCS protocols targeting the primary motor cortex were applied in two separate sessions (at least 2 weeks apart): active (2 mA for 20 min) and sham stimulation. Seven trials with the backward translation of the support base (20 cm/s and 5 cm) were performed after tDCS. Postural outcomes included the recovery time to stable position and onset latency of the medial gastrocnemius (MG). Pearson and Spearman correlation tests were performed. RESULTS: No significant correlations were observed between clinical/cognitive characteristics and tDCS-related changes in postural responses. Negative associations were observed between the baseline level of postural control and tDCS-related changes in postural responses for the recovery time (r = -0.657; p < 0.001) and the MG onset latency (rs = -0.539; p = 0.007). PwPD with worse baseline postural control demonstrated greater improvement after active stimulation. CONCLUSIONS: Findings suggest that tDCS-related effects on postural response to perturbation are related to the baseline level of postural control, but not to clinical characteristics in PwPD. Those with worse baseline postural control responded better to tDCS.

Assessment of Force Production in Parkinson's Disease Subtypes.

Muscle weakness is a secondary motor symptom of Parkinson's disease (PD), especially in the subtype characterized by postural instability and gait difficulty (PIGD). Since the PIGD subtype also presents worse bradykinesia, we hypothesized that it also shows a decreased rate of force development, which is linked to an increased risk of falling in PD. Therefore, we investigated the effects of PD and PD subtypes on a force production profile and correlated the force production outcomes with clinical symptoms for each PD subtype. We assessed three groups of participants: 14 healthy older adults (OA), 10 people with PD composing the PIGD group, and 14 people with PD composing the tremor-dominant group. Three knee extension maximum voluntary isometric contractions were performed in a leg extension machine equipped with a load cell to assess the force production. The outcome measures were: peak force and rate of force development (RFD) at 50 ms (RFD50), 100 ms (RFD100), and 200 ms (RFD200). We observed lower peak force, RFD50, RFD100, and RFD200 in people with PD, regardless of subtypes, compared with the OA group (p < 0.05 for all comparisons). Together, our results indicated that PD affects the capacity to produce maximal and rapid force. Therefore, future interventions should consider rehabilitation programs for people with PD based on muscle power and fast-force production, and consequently reduce the likelihood of people with PD falling from balance-related events, such as from an unsuccessful attempt to avoid a tripping hazard or a poor and slower stepping response.

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.

Cortical Activity Underlying Gait Improvements Achieved With Dopaminergic Medication During Usual Walking and Obstacle Avoidance in Parkinson Disease.

BACKGROUND: Dopaminergic medication improves gait in people with Parkinson disease (PD). However, it remains unclear if dopaminergic medication modulates cortical activity while walking. OBJECTIVE: We investigated the effects of dopaminergic medication on cortical activity during unobstructed walking and obstacle avoidance in people with PD. METHODS: A total of 23 individuals with PD, in both off (PDOFF) and on (PDON) medication states, and 30 healthy older adults (control group [CG]) performed unobstructed walking and obstacle avoidance conditions. Cortical activity was acquired through a combined functional near-infrared spectroscopy electroencephalography (EEG) system, along with gait parameters, through an electronic carpet. Prefrontal cortex (PFC) oxygenated hemoglobin (HbO2) and EEG absolute power from FCz, Cz, and CPz channels were calculated. RESULTS: HbO2 concentration reduced for people with PDOFF during obstacle avoidance compared with unobstructed walking. In contrast, both people with PDON and the CG had increased HbO2 concentration when avoiding obstacles compared with unobstructed walking. Dopaminergic medication increased step length, step velocity, and ß and γ power in the CPz channel, regardless of walking condition. Moreover, dopaminergic-related changes (ie, on-off) in FCz/CPz γ power were associated with dopaminergic-related changes in step length for both walking conditions. CONCLUSIONS: PD compromises the activation of the PFC during obstacle avoidance, and dopaminergic medication facilitates its recruitment. In addition, PD medication increases sensorimotor integration during walking by increasing posterior parietal cortex (CPz) activity. Increased γ power in the CPz and FCz channels is correlated with step length improvements achieved with dopaminergic medication during unobstructed walking and obstacle avoidance in PD.

Effect of Different Intensities of Transcranial Direct Current Stimulation on Postural Response to External Perturbation in Patients With Parkinson's Disease.

BACKGROUND: Habituation of postural response to perturbations is impaired in people with Parkinson's disease (PD) due to deficits in cortico-basal pathways. Although transcranial direct current stimulation (tDCS) modulate cortico-basal networks, it remains unclear if it can benefit postural control in PD. OBJECTIVE: To analyze the effect of different intensities of anodal tDCS on postural responses and prefrontal cortex (PFC) activity during the habituation to the external perturbation in patients with PD (n = 24). METHODS: Anodal tDCS was applied over the primary motor cortex (M1) with 1 mA, 2 mA, and sham stimulation in 3 different sessions (~2 weeks apart) during 20 minutes immediately before the postural assessment. External perturbation (7 trials) was applied by a support base posterior translation (20 cm/s and 5 cm). Primary outcome measures included lower limb electromyography and center of pressure parameters. Measures of PFC activity are reported as exploratory outcomes. Analyses of variance (Stimulation Condition × Trial) were performed. RESULTS: Habituation of perturbation was evidenced independent of the stimulation conditions. Both active stimulation intensities had shorter recovery time and a trend for lower cortical activity in the stimulated hemisphere when compared to sham condition. Shorter onset latency of the medial gastrocnemius as well as lower cortical activity in the nonstimulated hemisphere were only observed after 2 mA concerning the sham condition. CONCLUSIONS: tDCS over M1 improved the postural response to external perturbation in PD, with better response observed for 2 mA compared with 1 mA. However, tDCS seems to be inefficient in modifying the habituation of perturbation.

Utility of center of pressure measures during obstacle crossing in prediction of fall risk in people with Parkinson's disease.

INTRODUCTION: Postural instability during walking and tripping over obstacles are the main causes of falls in people with Parkinson's disease (PD). Preliminary limited evidence suggests that the length of the prospective follow-up period affects falls prediction in PD, with shorter periods leading to more accurate prediction. Thus, the primary aim of the present study was to test the performance of center of pressure (CoP) variables during obstacle crossing to predict fall risk in people with PD during subsequent periods of four, six, and 12 months. We also compared CoP variables during obstacle crossing between fallers and non-fallers. METHODS: Forty-two individuals with PD, in mild to moderate stages, completed the baseline obstacle crossing assessment and reported falls for 12 months. Participants walked at their self-selected pace and were instructed to cross an obstacle (half knee height) positioned in the middle of an 8-m long pathway. A force platform was used to analyze CoP parameters of the stance phase of the trailing limb (most affected limb). The ability of each outcome measure to predict fall risk at four, six, and 12 months was assessed using receiver operating characteristic curve analyses. RESULTS: Ten individuals (23.8%) were considered fallers at four months, twelve individuals (28.5%) at six months, and twenty-one individuals (50%) at 12 months. CoP amplitude and CoP velocity in the mediolateral direction significantly predicted fall risk at four, six, and 12 months. As judged by the area under the curve, mediolateral CoP velocity showed the best performance at four months, while mediolateral CoP amplitude showed the best performance at six months. Fallers presented greater values of mediolateral CoP velocity and amplitude than non-fallers. CONCLUSION: These findings suggest that mediolateral CoP velocity and amplitude during obstacle crossing might be useful to predict fall risk in people with PD. Therefore, larger studies are encouraged.

The effects of habitual footwear in gait outcomes in people with Parkinson's disease.

BACKGROUND: Gait is impaired in individuals with Parkinson's disease (PD). Although the effect of habitual footwear on gait spatiotemporal parameters has already been established in neurologically healthy individuals, its effects on people with PD is unknown. RESEARCH QUESTION: This study aimed to investigate the impact of habitual footwear on the step spatiotemporal parameters in people with PD. METHODS: Sixteen individuals with PD (G-PD) and 15 neurologically healthy individuals (G-HC) were assessed. Participants walked on an 8 m long pressure sensitive walkway at their preferred speed with and without their habitual footwear (3 trials per condition). Footwear included flip-flops, shoes, sneakers and sandals. The average, variability and asymmetry for step length, width, duration, and velocity and the percentage time in the swing and stance phases were calculated. RESULTS: The results showed in both groups a reduced percentage time in the swing phase and an increased step width, duration and length with footwear (F(1,29)>5.64; p<0.02). Additionally, habitual footwear increased step width variability in G-PD and G-HC (F(1,29)=3.97; p=0.06). Interestingly, only G-HC showed a higher step length asymmetry in the footwear condition than in the barefoot condition (p=0.02). Finally, only when habitual footwear was used, G-HC showed a higher step velocity asymmetry than G-PD (p=0.04). SIGNIFICANCE: These results indicate a negative influence of footwear on gait spatiotemporal parameters in both groups. Furthermore, footwear induced differences between groups. These findings indicate that footwear use is an influencing factor in studies comparing people with PD and healthy elderly. Further data are needed before definitive recommendations are made.

RCVibro System: full description of a custom-made vibratory system and its reliability.

BACKGROUND: The use of local muscle vibration is a promising technique to improve motor performance in people with movement impairments. Majority of studies have failed to properly describe the used system and its reliability, making it difficult to transfer this promising technique to clinical practice. OBJECTIVE: To describe technical details of a custom-made vibratory system (RCVibro System), as well as to determine its reliability and functionality. METHODS: The vibration frequency and the electric potential difference/vibration frequency curve of six devices were assessed (at the same day and at different days), allowing us to determine the system reliability. In addition, the RCVibro System functionality was analyzed by the center-of-pressure behavior assessment during the tibialis anterior bilateral stimulation in fifteen young people. RESULTS: The RCVibro System showed a very-high reliability between assessments within the same day (ICC(2,6) ranging from 0.95 to 0.99; p<0.01) and between different days (ICC(2,6) ranging from 0.81 to 0.98; p<0.01). We also observed a forward center-of-pressure displacement (p<0.01) and an increase in the center-of-pressure velocity (p<0.01). CONCLUSION: We conclude that RCVibro System is a highly reliable system. The results demonstrate the potential usage of RCVibro System in clinical and research settings. Further investigation is needed in people with motor and neurological disorders.

Predictors of the functional reach test in people with parkinson's disease / Preditores do desempenho no teste de alcance funcional em pessoas com doença de parkinson

ABSTRACT Postural instability, a fundamental signal/symptom of Parkinson's disease (PD), is characterized by the association between postural alignment, joint range of motion, and muscular rigidity. The aim of the present study was to analyze the relationship between performance in the functional reach test (FRT) and associated factors such as joint range of motion and PD clinical features. Twenty-five people with PD in stages 1 and 1.5 of the Hoehn & Yahr scale participated in the study. The analyzed dependent variables were: FRT performance and scores in the items of clinical evaluation of the Unified Parkinson's Disease Rating Scale: pull-test, motor rigidity, and motor condition were used. The average distance in the FRT was 25.3 cm and the mean anterior-posterior displacement of the center of pressure was 2.69 cm. The ankle range of motion was associated with FRT performance, while postural stability was associated with the anterior-posterior displacement of the center of pressure during the FRT. We conclude that FRT performance in people with PD is determined by the individual level of balance and by the ankle joint amplitude and muscular rigidity and functional alterations due to aging are responsible for FRT performance.

RESUMO A instabilidade postural, um sinal/sintoma cardinal da doença de Parkinson (DP), é caracterizada pela associação entre alinhamento postural, amplitude de movimento e rigidez muscular. O objetivo foi analisar a relação entre o desempenho no teste de alcance funcional (TAF) e fatores relacionados a amplitude de movimento e aspectos clínicos da doença. Participaram 25 pessoas com DP nos estágios 1,0 e 1,5 da Hoehn e Yahr. As variáveis dependentes analisadas foram: desempenho no TAF e as pontuações nos itens da avaliação clínica da UnifiedParkinson'sDisease Rating Scale: teste de retropulsão, rigidez muscular e condição motora. A distância média no TAF foi de 25,3 cm e o deslocamento anteroposterior médio do centro de pressão foi de 2,69 cm. A amplitude de movimento articular do tornozelo está associada ao desempenho no TAF, enquanto a estabilidade postural está associada ao deslocamento anteroposterior do centro de pressão durante o TAF. Conclui-se que o desempenho no TAF em pessoas com DP é determinado pelo nível individual de equilíbrio e pela amplitude articular do tornozelo e a rigidez muscular e alterações funcionais do envelhecimento são responsáveis pelo desempenho no TAF.

PARKINSON'S DISEASE PATIENTS WITH DOMINANT HEMIBODY AFFECTED BY THE DISEASE RELY MORE ON VISION TO MAINTAIN UPRIGHT POSTURAL CONTROL.

This study assesses the association between disease onset side (dominant or non-dominant) and vision on postural control of Parkinson's disease patients. Patient volunteers composed two groups, according to the onset side affected: Dominant group (n=9; M age=66.1 yr., SD=7.2; 6 women, 3 men) and Non-dominant group (n=9; M age=67.4 yr., SD=6.4; 6 women, 3 men). The groups' postural control was assessed by posturography during quiet upright stance in two conditions, Eyes open and Eyes closed. Two-way analyses of variance (ANOVAs; group×condition) with repeated measures for the second factor assessed the differences associated with affected hemibody and vision on postural control. Analyses indicated that patients with the dominant side affected also presented significantly greater variation in center of pressure than those with the non-dominant side affected, mainly in the Eyes closed condition. The results demonstrate a higher reliance on vision in the dominant side, possibly to compensate somatosensory system impairments. These results also highlight the importance of analyzing the hemibody affected by the disease when postural control is assessed in this population.

Análise cinética e cinemática do levantar e andar em jovens e idosos / Kinetic and kinematic analysis of sit to walk task in young and elderly people / Análisis cinético y cinemático de la acción de levantarse y caminar en jóvenes y personas mayores

ResumoA tarefa de levantar e andar (LEA) é muito usada no dia a dia e há a necessidade de conhecer o comportamento de idosos nesse tipo de ação. Diante disso, o objetivo foi avaliar jovens (GJ) e idosos (GI) na tarefa de LEA. Foram realizadas avaliações cinéticas e cinemáticas e do desempenho da tarefa entre os grupos. Após a análise estatística, foi observada apenas diferença estatística para a variável de máxima força vertical durante a fase perda de contato com o assento ao término do levantar, assim como o tempo de desempenho dessa fase foi menor para o GJ. O envelhecimento causa um impacto significativo na força e contribui, assim, para um maior dispêndio de tempo ao levantar da cadeira. Com isso, maior atenção deve ser dada à fase de transição da LEA.

AbstractThe sit to walk (STW) is a task performed in daily life and is needed to know the older people behavior in this task. Therefore, the aim of this study was to evaluate young (YG) and older people (OG) when performing the STW. Kinetic, kinematic and task performance were assessed by each group. Statistical procedures showed differences only for vertical maximal ground reaction force during the seat off, such as the lower time to perform this phase for YG. The aging lead a significant impact in the strength force in limbs, due to this the elderly spend more time to rising up a chair. Therewith greater attention is necessary in transition phase, mainly by elderly exposure and increased chance of falls.

ResumenLa acción de levantarse y caminar (LYC) es muy frecuente en la vida diaria y es necesario saber cómo la realizan las personas mayores. Por tanto, el objetivo de este estudio ha sido evaluar a personas jóvenes (PJ) y personas mayores (PM) cuando realizan la acción de LYC. Se llevaron a cabo mediciones de tipo cinético, cinemático y del desempeño de esta acción en cada grupo. Los procedimientos estadísticos mostraron diferencias solo en la máxima fuerza vertical de reacción terrestre al levantarse del asiento, así como en el menor tiempo empleado por las PJ para llevar a cabo esta fase. El envejecimiento causa un impacto significativo en la fuerza de las extremidades y por ello las personas mayores necesitan más tiempo para levantarse de una silla. De esta manera, es necesario prestar mayor atención a la fase de transición de la acción de LYC.

Positive effects of auditory cue in locomotor pattern of people with Parkinson's disease (off and on medication) / Efeito positivo da dica auditiva no padrão locomotor de pacientes com doença de Parkinson

Gait disorders are identified in people with Parkinson's disease. The aim of this study was to investigate the effect of auditory cues and medication on kinematic, kinetic and EMG parameters, during different gait phases of people with PD and healthy elderly. Thirty subjects distributed in two groups (Group 1, PD patients off and on medication; Group 2, healthy elderly) participated in this study and were instructed to walk in two experimental conditions: non-cued and cued. Therefore, kinematic, kinetic and electromyography analyses were utilized to investigate the locomotor pattern. Changes in locomotor pattern (greater muscular activity) with auditory cue were observed for PD patients. Regarding the medication, locomotor parameter improvement was observed after levodopa intake in association with the auditory cue. These results confirm the hypothesis about the external cues therapy that could be used as a complement to drug therapy to achieve improvement in the locomotor pattern of PD patients

Mudanças na marcha são identificadas em pacientes com doença de Parkinson (DP). O objetivo deste estudo foi investigar o efeito da dica auditiva e do medicamento nos parâmetros cinemáticas, cinéticos e eletromiograficos durante diferentes fases da marcha em pacientes com DP e idosos sadios. 30 indivíduos distribuídos em dois grupos (Grupo 1, pacientes com DP; Grupo 2, idosos sadios) participaram deste estudo e foram instruídos a realizarem duas tarefas experimentais: marcha com e sem dica auditiva. Análise cinemática, cinética e eletromiográficas foram utilizadas para investigar o padrão locomotor. Mudanças no padrão locomotor (maior ativação muscular) foram observadas para os pacientes com DP. Em relação à medicação, melhoras no padrão locomotor foram observadas após a ingestão da levodopa em associação com a dica auditiva. Estes resultados confirmam a hipótese sobre a terapia com dicas externas, que pode ser utilizada como um complemento à terapia medicamentosa para melhorar o padrão locomotor de pacientes com DP

Efecto de los diferentes programas de ejercicios en las funciones psicológicas y cognitivas de las personas con enfermedad de Parkinson / Efeito de diferentes programas de exercício sobre as funções psicológicas e cognitivas das pessoas com doença de Parkinson / Effect of different exercise programs on the psychological and cognitive functions of people with Parkinson's disease

The purpose of this study was to analyze the effect of different exercise programs on the psychological and cognitive functions in patients with Parkinson's disease (PD). Forty-five patients with PD participated in the study. The participants were randomized in three intervention programs: Group-1 (n=15, cognitive-activities), Group-2 (n=15, multimodal exercise) and Group-3 (n=15, exercises for posture and gait). The clinical, psychological and cognitive functions were assessed before and after 4 months of intervention. Univariate analysis did not reveal significant interactions between groups and time (p>0.05). However, univariate analysis for time revealed differences in stress level and memory. Participants showed less physical stress (p<0.01) and overall stress (p < 0.04) and higher performance in episodic declarative memory (p < 0.001) after exercise. These findings suggest that group work with motor or non-motor activities can improve cognitive and psychological functions of patients with PD.

O objetivo deste estudo foi analisar o efeito de diferentes programas de exercício físico nas funções psicológicas e cognitivas em pacientes com doença de Parkinson (DP). Participaram do estudo 45 pacientes com DP, distribuídos aleatoriamente em três programas de intervenção: Grupo-1 (n=15, atividades cognitivas), Grupo-2 (n=15 exercício multimodal) e Grupo-3 (n=15, exercícios para a postura e a marcha). As funções clínicas, psicológicas e cognitivas foram avaliadas antes e após 4 meses de intervenção. A análise univariada não revelou interação significativa entre grupo e momento (p>0,05). No entanto, a análise univariada para momento revelou diferenças no nível de estresse e memória. Os participantes mostraram redução do estresse físico (p<0,01) e estresse global (p<0,04) e melhora na memória declarativa episódica (p<0,001) após a intervenção. Estes achados sugerem que o trabalho em grupo, com atividades motoras ou não motoras, pode melhorar as funções cognitivas e as condições psicológicas de pacientes com DP.

El objetivo del estudio fue analizar el efecto de diferentes programas de ejercicios en las funciones cognitivas y psicológicas en pacientes con enfermedad de Parkinson (EP). Cuarenta y cinco pacientes con EP que fueron divididos aleatoriamente en tres intervenciones: Grupo-1 (n=15, actividades cognitivas), Grupo-2 (n=15 ejercicio multimodal) y Grupo-3 (n=15, ejercicios para la postura y la marcha). Las funciones clínicas, psicológicas y cognitivas fueron evaluadas antes y después de 4-meses de intervención. Análisis univariante reveló interacción significativa entre el grupo y el tiempo (p>0,05). Obstante, análisis univariada para tiempo reveló diferencias en el nivel de estrés y la memoria. Los participantes mostraron una reducción del estrés físico (p<0,01) y el estrés en general (p<0,04) y mejora de la memoria declarativa episódica (p<0,001) después de la intervención. Estos hallazgos sugieren que el trabajo en grupo, actividades motoras y non-motoras, pueden mejorar las funciones cognitivas y psicológicas de los pacientes con EP.

Empeoramiento de la enfermedad de Parkinson y componentes de subtipo motor influencia la condición física / Agravo da doença de Parkinson e subtipo motor influencia componentes da capacidade física / Parkinson's disease severity and motor subtype influence physical capacity components

The severity of Parkinson's disease (PD) and PD's motor subtypes influence the components of physical capacity. The aim of this study was to investigate the impact of both PD severity and motor subtype in the performance of these components. Thirty-six PD patients were assigned into four groups: Tremor (TD) initial and TD mild, akinetic-rigid (AR) initial, and AR mild. Patients' strength, balance, coordination, mobility and aerobic capacity were evaluated and groups were compared using a two-way ANOVA (severity and subtype as factors). AR presents a poorer performance than TD in almost all tests. Also this performance was worsened with the advance of the disease in AR, contrary to TD. We conclude that AR and TD subgroups are different about their performance on physical capacity components, moreover, this performance worsens with the advance of the disease of the AR group, but not for TD.

A doença de Parkinson (DP) é caracterizada por diferentes subtipos motores e supõe-se que o desempenho dos componentes da capacidade física é influenciado por esses subtipos. O objetivo desse estudo foi investigar o impacto que a severidade e o subtipo da DP podem trazer sobre o desempenho dos componentes da capacidade física. Trinta e seis pacientes com DP foram distribuídos em quarto grupos: com dominância de tremor (TD) inicial e TD intermediário ou acinesia (AR) inicial e AR intermediário. A força, equilíbrio, coordenação, mobilidade e capacidade aeróbia foram avaliados. AR apresentou um pior desempenho que TD em nos testes. Esse desempenho foi pior com o aumento da severidade da doença em AR, mas não em TD. Conclui-se que os grupos AR e TD são diferentes em relação ao desempenho dos componentes da capacidade física, mas principalmente, esse desempenho piora com o avanço da doença em AR, mas não em TD.

La enfermedad de Parkinson (EP) se caracteriza por subtipos motor, y se supone que el rendimiento de los componentes físicos de capacidad es influenciada por aquellos subtipos. El objetivo de este estudio fue investigar el impacto tanto de la severidade y subtipo de la PD en el rendimiento de estos componentes. Treinta y seis pacientes con EP se distribuyeron en: Temblor (TD) inicial y TD suave, acinesia (AR) inicial y AR suave. Fuerza, equilibrio, coordinación, la movilidad y la capacidad aeróbica fueron evaluados. AR presenta un desempeño más pobre que TD en las pruebas. También este comportamiento se agravó con el avance de la enfermedad en AR, diferente que en TD. Como conclusión AR y TD son diferentes en respecto a su rendimiento en los componentes físicos de capacidad, pero sobre todo, esto empeora con el aumento de avance de la enfermedad en el grupo de AR, pero no en TD.

Parâmetros na marcha na paralisia supranuclear progressiva: um estudo de caso / Gait parameters in progressive supranuclear palsy: a case study

INTRODUÇÃO: Comprometimentos na marcha de pacientes com paralisia supranuclear progressiva (PSP) podem aumentar o risco de quedas durante o andar, especialmente em ambientes complexos. OBJETIVO: Descrever o comportamento locomotor de uma paciente com PSP, nas condições de marcha livre e marcha adaptativa. MATERIAIS E MÉTODOS: Estudo de caso de uma paciente com PSP (71 anos). Para análise cinemática, nas condições de marcha livre, com obstáculo baixo e alto, uma câmera digital registrou uma passada completa da paciente. RESULTADOS: Com o aumento da complexidade do ambiente (marcha livre, obstáculo baixo e alto, respectivamente), foi observada diminuição do comprimento do passo (0,37 ± 0,07; 0,30 ± 0,07; 0,26 ± 0,06 m), do comprimento da passada (0,71 ± 0,11; 0,58 ± 0,15; 0,47 ± 0,07 m) e da velocidade da passada (0,55 ± 0,14; 0,43 ± 0,11; 0,36 ± 0,11 m/s). Aumento progressivo ocorreu na duração do duplo suporte da passada livre (29,47%) para a passada antes do obstáculo alto (41,11%). Observou-se, ainda, ligeira diminuição na distância vertical pé/obstáculo alto (membro/abordagem: 7,18 ± 1,88; e membro/suporte: 8,84 ± 2,57 cm) em relação ao obstáculo baixo (membro de abordagem: 8,86 ± 1,88; e membro de suporte: 11,67 ± 2,09 cm). CONCLUSÃO: A PSP afetou de forma evidente a marcha da paciente. Inflexibilidade para a adaptação da marcha às demandas do ambiente foi observada durante a aproximação e a transposição dos obstáculos, o que pode aumentar o risco de tropeços e quedas.

INTRODUCTION: Gait impairments in patients with progressive supranuclear palsy (PSP) can lead to increased risk of trips and falls while walking, especially in complex environments. OBJECTIVE: To describe the locomotor behavior of a woman with PSP during free and adaptive walking. MATERIALS AND METHODS: A case study of a PSP patient (71 years old). For kinematic data collection during free and adaptive walking (low and high obstacle crossing), a digital camcorder captured an entire gait cycle of the patient. RESULTS: Decrease in step length (0.37 ± 0.07; 0.30 ± 0.07; 0.26 ± 0.06 m), stride length (0.71 ± 0.11; 0.58 ± 0 15; 0.47 ± 0.07 m), and stride velocity values (0.55 ± 0.14, 0.43 ± 0.11, 0.36 ± 0.11 m/s) was observed with the increasing of complexity (free walking, low obstacle crossing, and high obstacle crossing, respectively). The patient showed greater duration of double support phase in the high obstacle condition (41.11%) than in the free walking condition (29.47%). Also, toe clearance distance was slightly shorter in high obstacle condition (leading limb: 7.18 ± 1.88 and trailing limb: 8.84 ± 2.57 cm) than in the low obstacle condition (leading limb: 8.86 ± 1.88 and trailing limb: 11.67 ± 2.09 cm). CONCLUSION: PSP clearly impairs the patient's gait. The patient showed inflexibility to adapt to environmental demands during both approaching and crossing obstacle. This behavior could increase the risk of trips and falls.

Proprioceptive neuromuscular facilitation does not increase blood pressure of healthy elderly women.

Proprioceptive neuromuscular facilitation (PNF) is an attractive method to increase strength and proprioception of elderly individuals. However, a major clinical concern about the prescription of PNF is the belief that it can cause a cardiovascular overload, because it involves close-to-maximal loads and isometric contractions. Yet the acute effect of a PNF training session on cardiovascular response in elderly individuals is still unknown. Hence, the objective of this study was to evaluate the effect of PNF on diastolic and systolic blood pressure of healthy elderly people. Fifteen older women (mean age 72.40±6.82 years) performed three sets (five repetitions each) of three different PNF techniques (rhythmic initiation, dynamic reversion, and isotonic combination), executing a single movement pattern. Diastolic and systolic blood pressure (DBP and SBP) were evaluated by means of a manual sphygmomanometer immediately before and during the last two repetitions (last set) of each technique. A two-way ANOVA test (time and technique) was performed to investigate the PNF effect on blood pressure. No time (preexercise to postexercise) (p=0.33 for DBP; p=0.06 for SBP) or PNF technique (p=0.75; p=0.81) effect were observed. In conclusion, we can state that the execution of these PNF techniques is safe for the cardiovascular system of healthy elderly women, because no blood pressure increases were found.

Muscular coactivation (CA) around the knee reduces power production in elderly women.

The main objective of this paper was to study the influence of muscular CA around the knee on the rate of force development (RFD) in older women. After personal invitation, 12 older women, participated in the study. Volunteers performed maximal voluntary isometric knee extension and flexion contractions (MVC) where the RFD was determined (considering the first 50, 100 and 200 ms after the force production onset; also, the time necessary to achieve 30% and 50% MVC was considered). Electromyography data from quadriceps and hamstrings were used to determine different CA indexes (CAIs). A correlation test was applied between CAI and RFD; different methods to determine CAI were also compared (Wilcoxon test). The CAI determination methods were not different one from another (p>0.05) and were significantly correlated with RFD (p<0.05) in special, when time to achieve 30% MVC and 50% MVC were considered (|r|=0.89 and r(2)=0.79; |r|=0.93 and r(2)=0.86; p<0.0001). These results clearly state the CA influence over the capacity to produce force in a short period of time in elderly women, what can increase falling risk, since it is essential to recover to gait disturbances and to unbalance.

Levantamento manual de carga repetitivo de curta duração com e sem o uso de cinto pélvico: efeito sobre a atividade EMG normalizada por diferentes indicadores / Effect of a pelvic belt on EMG activity during manual load lifting

A capacidade de levantamento e abaixamento manual de carga (LAMC) continua preocupando as indústrias e o uso da eletromiografia (EMG) se apresenta como uma alternativa no estudo da musculatura envolvida nessa atividade. Entretanto, a reprodutibilidade destas medidas torna-se primordial. Assim, esse estudo teve como objetivo principal analisar a influência do uso do cinto pélvico sobre a atividade EMG dos músculos eretores da espinha (ER) e reto femoral (RF), durante LAMC e durante a contração isométrica voluntária máxima (CIVM) de extensão do tronco, realizada antes (PRÉ) e após essa atividade, assim como analisar a variabilidade (CV) do sinal EMG quando normalizadas por três métodos: pelo pico (PICO) e pela média (MED) da atividade EMG e pelo sinal obtido durante a CIVM. Para isso, 8 voluntários realizaram LAMC de 15% e 25% peso corporal (PC), com e sem o uso do cinto pélvico por 1min. Obtiveram-se os valores do Coeficiente da Variação (CV) do sinal EMG do ER e RF durante os LAMCs. Durante as CIMVs, obtiveram-se os valores de tração na célula de carga e as variáveis eletromigráficas RMS, Frequência Média, Frequência Mediana e Potência Total do músculo ER. Os resultados demonstram menores valores de CV quando o sinal EMG foi obtido pelo PICO, sendo, portanto, esse método preferível por apresentar menor variabilidade. Durante as CIVMs, somente a força de tração na célula de carga se apresentou menor após o LAMC de 25%PC sem o uso do cinto pélvico (p=0,035), sugerindo rápida recuperação dos ER após o LAMC por 1 minuto.

Manual lifting (ML) capacity is still a matter of concern for industry administrators and electromyography (EMG) seems to be a good alternative for the evaluation of muscles involved in this task. However, the reliability of these measures is very important. Thus, the objective of this study was to evaluate the influence of a pelvic belt on EMG activity of the erector spinus (ES) and rectus femoralis (RF) muscles during ML and during maximal voluntary contractions (MVC) of trunk extension performed before (baseline) and after ML. In addition, the variabilityin the EMG signal normalized by the following three different methods was evaluated: peak EMG activity, mean EMG activity, and EMG activity obtained during MVC. Eight volunteers performed ML of 15% and 25% of their body weight for 1 minute in the presence or absence of a pelvic belt. The coefficient of variation (CV) of the EMG signal obtained for the ES and RF muscles was calculated during ML. Load cell traction values and the electromyographic variables RMS, median frequency, mean power frequency and total power of the ES muscle were obtained during MVC. The results showed lower CV (smaller variability) when the EMG signal was normalized by peak activity, with this method thus being preferable. During MVC, only the load cell traction value differed from baseline after ML of 25% body weight without the pelvic belt (p=0.035), a finding suggesting rapid recovery of ES muscle after ML for 1 minute.

Physiological and neuromuscular profile during a bodypump session: acute responses during a high-resistance training session.

The main purposes of this study were 1) to describe and to compare blood lactate ([La]), heart rate (HR), and electromyographic (EMG) parameters during high-repetition training sessions (HRTSs), 2) to analyze the influence of physical fitness levels in these parameters, and, 3) to analyze the relationship between metabolic ([La]) and neuromuscular (EMG) responses during the HRTS. Fifteen healthy untrained women (21.7 +/- 2.1 years) performed an HRTS called Bodypump for 1 hour, which incorporated the use of variable free weights and high repetitions in a group setting. This session involved 10 music selections (M1-M10) containing resistive exercises for different muscle groups. After music selections 2 (M2), 4 (M4), 6 (M6), 7 (M7), and 9 (M9), [La], HR, and EMG (vastus medialis [VM], vastus lateralis [VL], iliocostalis lumborum [IC], and longissimus thoracis <) were determined. The [La] (M2, 4.00 +/- 1.45 mM; M7, 5.02 +/- 1.73 mM) and HR (M2, 153.64 +/- 18.89 bpm; M7, 16.14 +/- 20.14 bpm) obtained at M2 and M7 were similar but were significantly higher than the other moments of the session. However, EMG (root mean square [RMS]) at M2 (VL, VM, and LT) was lower than at M7. There was no significant correlation of strength and aerobic physical fitness with [La], RMS. In the same way, there was no significant correlation of [La] with RMS at M2 and M7. On the basis of our data, we can conclude that metabolic, cardiovascular, and EMG variables present different and independent behavior during an HRTS. Accordingly, for neuromuscular conditions during HRTS, it seems to be enough to induce improvement in the muscular strength of inferior limbs in untrained subjects.