Decreased automaticity contributes to dual task decrements in older compared to younger adults.

PURPOSE: To contrast older and younger adults' prefrontal cortex (PFC) neural activity (through changes in oxygenated hemoglobin) during single and dual tasks, and to compare decrements in task performance. METHODS: Changes in oxygenated hemoglobin of dorsolateral PFC were monitored using functional near-infrared spectroscopy during single tasks of spelling backwards (cognitive task) and 30 m preferred paced walk; and a dual task combining both. Gait velocity was measured by a pressure sensitive mat. RESULTS: Twenty sex-matched younger (27.6 ± 3.5 years) and 17 older adults (71.2 ± 4.9 years) were recruited. The left PFC oxygenated hemoglobin decreased from start (1st quintile) to the end (5th quintile) of the walking task in younger adults ( - 0.03 ± 0.03 to - 0.72 ± 0.20 µM; p < .05) unlike the non-significant change in older adults (0.03 ± 0.06 to - 0.41 ± 0.32 µM, p > .05). Overall, oxygenation increased bilaterally during dual versus single walk task in older adults (Left PFC: 0.22 ± 0.16 vs. - 0.23 ± 0.21 µM, respectively; Right PFC: 0.17 ± 0.18 vs. - 0.33 ± 0.22 µM, respectively), but only in right PFC in younger adults ( - 0.02 ± 0.15 vs. - 0.47 ± 0.13 µM). Older adults exhibited lower velocity during the dual task compared to younger adults (1.03 ± 0.16 vs. 1.20 ± 0.17 m/s, respectively). Older age was associated with dual task cost on velocity during walking after adjusting for confounding variables. CONCLUSIONS: Age-related cognitive decline in older adults may increase neural activity for cognitive tasks and diminish walking automaticity that may lead to decrements during dual tasking; the greater PFC increases in the oxygenated hemoglobin and lower velocity may be due to increased cognitive load and limited attentional resources.

Changes in Oxyhemoglobin Concentration in the Prefrontal Cortex during Cognitive-Motor Dual Tasks in People with Chronic Obstructive Pulmonary Disease.

Cognitive and motor impairment are well documented in chronic obstructive pulmonary disease (COPD) patients, but their relationship has not been studied. This study evaluated and compared cognitive and motor performance during dual tasks and related dorsolateral prefrontal cortex (PFC) changes in oxygenated hemoglobin (ΔO2Hb), a proxy measure of neural activity, in patients with COPD and age-matched healthy individuals. Participants performed three single tasks: (1) backwards spelling cognitive task; (2) 30 m preferred paced walk; (3) 30 m fast walk, and two dual tasks: (4) preferred paced walk + backwards spelling; (5) fast paced walk + backwards spelling. The ΔO2Hb from left and right dorsolateral PFC were measured using functional near-infrared spectroscopy. Gait velocity was measured using a Zeno walkway. Compared to healthy adults (n = 20), patients with COPD (n = 15) had higher ΔO2Hb during single preferred (-0.344 ± 0.185 vs. 0.325 ± 0.208 µM; p = 0.011) and fast paced walk (-0.249 ± 0.120 vs. 0.486 ± 0.182 µM; p = 0.001) in right PFC. Among healthy adults, ΔO2Hb were higher bilaterally during preferred paced walking dual versus single task (right: 0.096 ± 0.159 vs. -0.344 ± 0.185 µM, p = 0.013; left: 0.114 ± 0.150 vs. -0.257 ± 0.175 µM, p = 0.049) and in right PFC during fast walking dual versus single task (0.102 ± 0.228 vs. -0.249 ± 0.120, p = 0.021). Patients with COPD did not increase O2Hb during dual versus single tasks. Patients with COPD exhibited slower velocity than older adults during all walking tasks. The lack of further increase in O2Hb from single to dual tasks in patients with COPD, may indicate reduced cognitive-motor capacity and contribute to poorer motor performance limiting safe ambulation. Dual tasking rehabilitation may improve neural efficiency to offset these risks.

The effect of mental tracking task on spatiotemporal gait parameters in healthy younger and middle- and older aged participants during dual tasking.

To evaluate the effect of dual tasking that combines walking with a mental tracking task on spatiotemporal gait parameters in younger and older adults. After completing the International Physical Activity Questionnaire (IPAQ), participants performed single tasks: preferred paced walk (PPW); fast paced walk (FPW); single-leg stance (SLS); spelling backwards cognitive task (CT). Thereafter, dual tasks: PPW + CT; FPW + CT; SLS + CT. Spatiotemporal gait parameters and the durations of SLS and SLS + CT were measured. Twenty younger and 20 older adults participated. The IPAQ scores were similar in both groups. Compared to the single task, stride length was shorter, stride time was longer, and stride length and time variability were higher during the PPW and FPW dual tasks in both groups. Older age was associated with shorter stride length during PPW and FPW, and longer stride time during FPW dual compared to single tasks. The older group exhibited shorter times during SLS and SLS + CT compared to younger group. Despite similar self-reported fitness, older age is associated with shorter stride length and longer stride time during FPW dual tasks as well as short times during SLS + CT, which may indicate diminished balance and posture stability.

Oxyhemoglobin changes in the prefrontal cortex in response to cognitive tasks: a systematic review.

PURPOSE OF THE STUDY: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design. MATERIAL AND METHODS: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility. RESULTS: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO2Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as "Working Memory" and "Verbal Fluency Tasks". CONCLUSIONS: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.

Balance and coordination training, but not endurance training, enhances synaptophysin and neurotrophin-3 immunoreactivity in the lumbar spinal cord after sciatic nerve crush.

INTRODUCTION: Numerous rehabilitation treatments have been shown to be useful for peripheral and central restoration after (PNI). METHODS: After sciatic nerve crush, we investigated 4 weeks of endurance training (ET) and balance and coordination training (BCT) with sciatic function index, hind-paw stride length, and spinal cord dorsal horn synaptophysin and neurotrophin-3 immunoreactivity. RESULTS: Our results demonstrated no significant differences between the non-trained (NT), ET, and BCT groups in sciatic functional index, and in stride-length analysis, but the ET showed higher values compared with the NT group. Synaptophysin immunoreactivity was higher in the BCT group compared with the NT group, and neurotrophin-3 immunoreactivity in the BCT group was greater compared with the other groups. CONCLUSION: BCT can positively affect spinal cord plasticity after a (PNI), and these modifications are important in the rehabilitation process.

Balance and coordination training and endurance training after nerve injury.

INTRODUCTION: Different rehabilitation treatments have proven useful in accelerating regeneration. METHODS: After sciatic nerve crush in rats, we tested balance and coordination training (BCT) and endurance training (ET) through sensorimotor tests and analyzed nerve and muscle morphology. RESULTS: After BCT and ET, rats performed better in sensorimotor tests than did non-trained animals. However, only BCT maintained sensorimotor function during training. Furthermore, BCT and ET produced significantly larger muscle area than in non-trained animals. CONCLUSIONS: These findings indicate that BCT and ET, when initiated in the early phase after sciatic nerve injury, improve morphological properties of the soleus muscle and sciatic nerve, but only the task-oriented BCT maintained sensorimotor function. The success of rehabilitative strategies appears to be highly task-specific, and strategies that stimulate sensory pathways are the most effective in improving balance and/or coordination parameters.

Evaluation of muscular and functional inter-limb asymmetries during mid-season in young male soccer athletes.

BACKGROUND: To identify inter-limb asymmetries through the knee's muscular and lower limb functional performance in young male soccer athletes. METHODS: Twenty male soccer athletes aged 17 to 19 from an under-20 team performed isokinetic tests at 60°/s., 120°/s., 180°/s., and 240°/s. To assess the knee extensors and flexors muscles and functional tests (hop tests and Y-balance test). RESULTS: There were no significant differences between the dominant limb (DL) and non-dominant limb (NDL) in the knee extensors and flexors peak torque and hamstrings (H)/quadriceps(Q) conventional ratio. Moreover, no angular velocities observed inter-limb asymmetries seen by values higher than 10% in the isokinetic parameters. However, the H/Q conventional ratio shows borderline values in low angular velocities (60°/s. and 120°/s.). No significant changes were observed in the functional test performance between the DL and NDL. Furthermore, we did not see inter-limb asymmetries in both hop and Y-balance tests. On the contrary, the anterior distance reached was lower than found in the literature, and the composite score of the Y-balance test demonstrated values below the normative (>94%). CONCLUSION: The data demonstrated that soccer athletes have muscular and functional inter-limb symmetry. However, they tend to have knee muscle imbalance in low velocities and dynamic balance deficits that might increase the risk of musculoskeletal injury.

Loss of Neural Automaticity Contributes to Slower Walking in COPD Patients.

The physical impairments (e.g., slower walking speed) in patients with chronic obstructive pulmonary disease (COPD) have been attributed to peripheral characteristics (e.g., muscle atrophy). However, cognitive impairment may compromise motor control including walking automaticity. The objective of this study was to investigate PFC neural activity, evaluated using changes in oxygenated hemoglobin (ΔO2Hb), during preferred paced walking (PPW) in COPD patients and age-matched controls. The ΔO2Hb from the left and right dorsolateral PFC was measured using functional near-infrared spectroscopy. Fifteen COPD patients (age: 71 ± 8) and twenty age-matched controls (69 ± 7 years) participated. Two-way mixed ANOVA demonstrated that O2Hb in both groups decreased during PPW from the start (quintile 1; Q1) to the end (quintile 5; Q5) in the left dorsolateral and medial PFC. Q1 was comprised of the data during the first 20% of the task, while Q5 included data collected in the last 20% of the task duration. PPW duration ranged between 30.0 and 61.4 s in the control group and between 28.6 and 73.0 s in COPD patients. COPD patients demonstrated a higher O2Hb in Q5 compared to the negative O2Hb in controls in the right medial and dorsolateral PFC during PPW. PPW velocity was lower in COPD patients compared to controls (1.02 ± 0.22 vs. 1.22 ± 0.14 m/s, p = 0.005). Healthy older controls exhibited automaticity during walking unlike patients with COPD. The lesser decrease in O2Hb in COPD patients may be attributed to increased executive demands or affect-related cues (e.g., pain or dyspnea) during walking.

Balance and coordination training after sciatic nerve injury.

INTRODUCTION: Numerous therapeutic interventions have been tested to enhance functional recovery after peripheral nerve injuries. METHODS: After sciatic nerve crush in rats we tested balance and coordination and motor control training in sensorimotor tests and analyzed nerve and muscle histology. RESULTS: The balance and coordination training group and the sham group had better results than the sedentary and motor control groups in sensorimotor tests. The sham and balance and coordination groups had a significantly larger muscle area than the other groups, and the balance and coordination group showed significantly better values than the sedentary and motor control groups for average myelin sheath thickness and g-ratio of the distal portion of the nerve. CONCLUSIONS: The findings indicate that balance and coordination training improves sciatic nerve regeneration, suggesting that it is possible to revert and/or prevent soleus muscle atrophy and improve performance on sensorimotor tests.

Effect of treadmill exercise on serotonin immunoreactivity in medullary raphe nuclei and spinal cord following sciatic nerve transection in rats.

The serotoninergic system modulates nociceptive and locomotor spinal cord circuits. Exercise improves motor function and changes dopaminergic, noradrenergic, and serotonergic central systems. However, the direct relationship between serotonin, peripheral nerve lesion and aerobic treadmill exercise has not been studied. Using immunohistochemistry and optic densitometry, this study showed that the sciatic nerve transection increased the serotoninergic immunoreactivity in neuronal cytoplasm of the magnus raphe nuclei of trained and sedentary rats. In the dorsal raphe nucleus the increase only occurred in sedentary-sham-operated rats. In the spinal cord of trained, transected rats, the ventral horn showed significant changes, while the change in dorsal horn was insignificant. Von Frey's test indicated analgesia in all exercise-trained rats. The sciatic nerve functional index indicated recovery in the trained group. Thus, both the aerobic treadmill exercise training and the nervous lesion appear to contribute to changes in serotonin immunoreactivity.

Dual-task activities impact the gait kinematics of both amputated and healthy participants similarly / As atividades de dupla tarefa impactam a cinemática da marcha de participantes amputados e saudáveis de forma semelhante

Abstract Introduction: Gait is the motor task most impacted by amputation, requiring several physical and cognitive adaptations. The interaction between cognition and movement can be validly assessed through dual-tasks analysis. Objective: To analyze the kinematics of single and dual-motor tasks of participants with transfemoral amputation and compare it with healthy participants. Methods: This is a comparative cross-sectional study in which 14 participants in the transfemoral amputee group and 14 non-amputee participants attended the Gait Laboratory of the Clinical Center of the Universidade de Caxias do Sul to perform cognitive and motor activities tests. Speed, cadence, stride width, stride length, step length and step time were analyzed. Results: Participants in the transfemoral amputee group presented impaired gait kinematic parameters when compared to non-amputates during single and dual-tasks. Both groups showed a similar percentage decrease in performance on the dual-task compared to the single task. Conclusion: There is a distinction observed in the gait patterns and parameters of both groups, as evidenced in both the simple gait assessment and the dual-task evaluation. The primary finding of our study suggests that changes in gait kinematics appear to be exacerbated by dual-tasking rather than solely by amputation.

Resumo Introdução: A marcha é a tarefa motora mais impactada pela amputação, exigindo várias adaptações físicas e cognitivas. A interação entre cognição e movimento pode ser validamente avaliada por meio da análise de duplas tarefas. Objetivo: Analisar a cinemática de tarefas motoras simples e duplas de participantes com amputação transfemoral e compará-las com participantes saudáveis. Métodos: Estudo transversal comparativo no qual 14 participantes do grupo de amputados trans-femorais e 14 participantes não amputados compareceram ao Laboratório de Marcha do Centro Clínico da Universidade de Caxias do Sul para realizar testes de atividades cognitivas e motoras. Foram analisados a velocidade, cadência, largura do passo, comprimento do passo, comprimento da passada e tempo de passo. Resultados: Os participantes do grupo de amputados transfemorais apresentaram parâmetros cine-máticos da marcha prejudicados em comparação com os não amputados durante as tarefas simples e duplas. Ambos os grupos mostraram uma diminuição percentual semelhante no desempenho na tarefa dupla em comparação com a tarefa simples. Conclusão: Uma distinção pode ser vista nos padrões e parâmetros da marcha de ambos os grupos, e não apenas na avaliação simples da marcha, mas especialmente na avaliação da dupla tarefa. A principal descoberta do nosso estudo sugere que as mudanças nos parâmetros da cinemática da marcha pa-recem ser exacerbadas não só pela amputação, mas também pela realização de duplas tarefas.

A influência dos níveis de atividade física nos parâmetros da marcha durante atividades de dupla tarefa em idosos / The influence of physical activity on gait parameters during dual-task activities in the older people

Resumo Objetivo Analisar as possíveis diferenças nas variáveis ​​cinemáticas da marcha entre idosos fisicamente ativos e fisicamente inativos durante a realização de atividades de dupla tarefa. Metodo: Participaram idosos, com idade entre 60 e 75 anos, divididos em dois grupos: fisicamente inativo (FI) (n=20) e fisicamente ativo (FA) (n=20). Os participantes foram agrupados igualmente em dez indivíduos do sexo feminino e masculino, classificados por meio do Questionário Internacional de Atividade Física (International Physical Activity Questionnaire - IPAQ). Os participantes realizaram inicialmente tarefas simples (aritmética, fluência verbal e marcha) e depois realizaram atividades de dupla tarefa, associando a marcha com as duas atividades cognitivas (aritmética e fluência verbal). Foram analisadas as variáveis ​​velocidade, cadência, comprimento da passada, largura do passo, tempo da passada e duplo apoio. Para comparar as variáveis ​​por tarefa e grupo, foi utilizado o modelo de Equações de Estimativas Generalizadas (GEE) complementado pelo teste de Bonferroni. Resultados Na análise intragrupo, ambos os grupos apresentaram reduções significativas na velocidade, cadência, largura da passada, tempo da passada e duplo apoio, tanto na dupla tarefa aritmética quanto na dupla tarefa de fluência verbal. No entanto, nas comparações entre os grupos, não houve diferenças estatisticamente significativas em nenhum parâmetro cinemático analisado, tanto na análise da marcha simples quanto nas tarefas duplas. Conclusão As duplas tarefas influenciaram negativamente os parâmetros cinemáticos da marcha em ambos os grupos. No entanto, o nível de atividade física não pode ser considerado um fator que minimiza os efeitos da dupla tarefa na marcha de idosos.

Abstract Objective To analyze the possible differences in the kinematic variables of gait between physically active and physically inactive older people while performing dual-task activities. Method Older individuals, aged between 60 and 75 years, participated, divided into two groups: physically inactive (PI) (n=20) and physically active (PA) (n=20). Participants were equally grouped into ten female and male individuals, classified using the International Physical Activity Questionnaire (IPAQ). Participants initially performed simple tasks (arithmetic, verbal fluency, and gait) and then performed dual task activities, associating gait with the two cognitive activities (arithmetic and verbal fluency). The variables velocity, cadence, stride length, step width, stride time and double support were analyzed. To compare variables according to task and group, the Generalized Estimating Equations (GEE) model complemented by the Bonferroni test was used. Results In the intragroup analysis both groups showed significant decreases in velocity, cadence, step width, stride time and double support, both in the arithmetic dual task and in the verbal fluency dual task. However, in the comparisons between the groups, there were no statistically significant differences in any kinematic parameter analyzed, both in the single gait analysis and in the dual tasks. Conclusion The dual tasks had a negative influence on the kinematic gait parameters in both groups. However, the level of physical activity can not be considered a factor that minimizes the effects of the dual task on gait in the older people.

Alterações na cinemática angular da marcha de pacientes hemiparéticos após Acidente Vascular Encefálico / Changes in gait angular kinematics of hemiparetic patients After Cerebrovascular Accident

O objetivo deste estudo foi analisar as alterações na cinemática angular da marcha de adultos com hemiparesia após acidente vascular encefálico (AVE). A amostra foi composta por 17 pacientes pós-AVE; e, para a avaliação da marcha, foi utilizado um sistema de captura da trajetória tridimensional da marcha. Quanto aos membros sadio e afetado, as variáveis estudadas foram: velocidade, ângulos máximos de flexão e extensão do quadril e joelho. Para as comparações entre os membros, foi utilizado o teste t pareado; e, para as comparações com valores normais, o teste t para uma amostra, considerando, como critério de decisão, o nível de significância p ≤ 0,05. Os resultados demonstraram, na comparação entre os membros, diferenças significantes na flexão (0,001) e extensão de joelho (0,05). Já na comparação entre o membro afetado e o sadio, destaca-se a diferença significante das angulações de flexão de joelho (<0,000) e extensão de quadril (0,004). Os pacientes com hemiparesia pós-AVE apresentam alterações na cinemática angular da marcha quando comparado o membro afetado com o sadio e com os valores da normalidade. Observou se um padrão de marcha predominantemente flexor, com grande variabilidade entre os pacientes avaliados.

This study aimed to analyze changes in gait angular kinematics of adults with hemiparesis after cerebrovascular accident (CVA). The sample consisted of 17 post- cerebrovascular accident (CVA) patients; and, for gait evaluation, it used a three-dimensional gait trajectory capture system. As for healthy and affected limbs, the variables studied were: speed, maximum angles of flexion, and extension of the hip and knee. For the comparisons between the members, the study used the t-paired test; and, for comparisons with normal values, it used the t test for a sample, whereas, as a decision criterion, the significance level p ≤ 0.05. The results showed, in the comparison between the limbs, significant differences in flexion (0.001) and knee extension (0.05). In the comparison between the affected limb and the healthy one, there is a significant difference in knee flexion angles (<0.000) and hip extension (0.004). Patients with post-CVA hemiparesis present changes in gait angular kinematics when the affected limb is compared with the healthy limb and with normal values. The study observed a predominantly flexor gait pattern, with a considerable variability among the evaluated patients.

The Effects of Two Different Exercise Programs on the Ultrastructural Features of the Sciatic Nerve and Soleus Muscle After Sciatic Crush.

Peripheral nerve injuries constitute a significant medical problem and the recovery is critically dependent on post-injury treatment. In this study, following sciatic nerve crush, we investigated the effects of a 4-week endurance training program (ET) and balance and coordination training program (BCT) on the ultrastructural features of the sciatic nerve and soleus muscle. The animals were randomly divided into Sham, non-trained (NT), ET, and BCT groups each of which included three animals. Ultra-thin cross and longitudinal sections (70-85 nm) were digitized and analyzed comparatively. The electron micrographic analysis of the sciatic nerve showed similar organelles features in the injury groups (myelin debris and swelling mitochondria). Nonetheless, the ET group presented better ultrastructural features as demonstrated by the greater predominance of rounded fibers and more defined organization in the myelinated axon bundles. In the soleus muscle's analyses, the injured groups demonstrated similar organelles' features (nucleus contained highly heterochromatic nuclei and smaller mitochondria). However, ET and BCT groups showed apparently enlarged myofibril cross-sectional areas and less collagen around muscle fibers, although, the ET group displayed reduced intermyofibrillar spaces and more closely aligned myofilaments when compared with the BCT group. Based on electron micrographic analysis, our findings suggest the presence of ultrastructural differences between the Sham, NT, and the trained groups. Therefore, exercise type seems to be responsible for producing some different positive features in the trained groups, while ET seems to have a more pronounced influence on the ultrastructural features of the sciatic nerve and the soleus muscle after a crush injury. Anat Rec, 300:1654-1661, 2017. © 2017 Wiley Periodicals, Inc.

Alterações na cinemática da marcha hemiparética: um estudo comparativo / Changes in the kinematics of hemiparetic gait: a comparative study

O objetivo principal deste estudo foi analisar as alterações da marcha de adultos com hemiparesia após acidente vascular encefálico (AVE) e comparar com sujeitos saudáveis. A amostra foi composta por 14 participantes do grupo AVE e 14 participantes pareados do grupo-controle (CON). Foi realizada uma análise tridimensional da marcha mediante um sistema de cinemetria. Os parâmetros analisados foram a velocidade, o comprimento da passada, a largura da passada, a cadência e o tempo da passada, sendo utilizado o teste t independente para as comparações entre os grupos e considerando p < 0,05 como critério de decisão. Os participantes do grupo AVE apresentaram valores médios significantemente inferiores em todos os parâmetros analisados. Além disso, os pacientes do grupo AVE também tiveram valores muito inferiores quando comparados aos de outros estudos com pacientes pós-AVE, possivelmente devido ao curto período entre o AVE (média de 14,14 meses) e a avaliação da marcha.

The main objective of this study was to analyze the gait alterations of adults with hemiparesis after cerebrovascular accident (CVA) and compare it with healthy subjects. The sample consisted of 14 participants from the stroke group and 14 matched participants from the control group (CON). A three-dimensional gait analysis was performed using a kinemetry system. The parameters analyzed were velocity, stride length, stride width, cadence, and stride time, using the independent t test for comparisons between groups and considering p < 0.05 as a decision criterion. Participants in the stroke group had significantly lower mean values in all analyzed parameters. In addition, patients in the CVA group also had much lower values when compared to other studies with post-CVA patients, possibly due to the short period between the CVA (mean of 14.14 months) and the gait assessment.

Avaliação muscular do joelho e funcional de membros inferiores de jovens atletas de voleibol do sexo feminino / Knee muscle evaluation and lower limbs' functional evaluation of young female volleyball athletes

Os desequilíbrios musculares e funcionais são analisados na tentativa de prevenir lesões e melhorar os desempenhos de atletas. Objetivo: Analisar o desempenho muscular de extensores e flexores de joelho e o desempenho funcional dos membros inferiores de atletas de voleibol. Métodos: Quinze atletas da categoria sub-16 de voleibol feminino da Universidade de Caxias do Sul foram avaliadas. Para análise do desempenho muscular, as variáveis pico de torque de extensores e flexores de joelho, e razão convencional de extensores/flexores, foi utilizado o dinamômetro isocinético. Já para a análise funcional dos membros inferiores, foram utilizados os testes Hop tests e Y balance test (YBT). Resultados: Na comparação entre membro dominante (MD) e não dominante (MND), não houve diferenças estatisticamente significativas na análise do pico de torque; já na razão flexores/extensores foi encontrada diferença significativa apenas à 240°/s. Entretanto, os valores médios da razão flexores/extensores encontrarem-se abaixo dos valores sugeridos pela literatura. As avaliações funcionais também não mostraram assimetrias entre os membros; no entanto, a pontuação composta do YBT apresentou-se abaixo dos valores normativos. Conclusão: A excelente simetria entre os membros pode ser justificada pela especificidade do esporte, pois os gestos esportivos do voleibol apresentam carácter simétrico durante as exigências físicas dos membros inferiores. No entanto, os baixos valores da razão flexores/extensores e da pontuação composta do YBT talvez não estejam diretamente relacionados a um risco maior de lesões já que os valores de referência utilizados são de atletas adultos.

Muscle and functional imbalances are analyzed in order to try prevent injuries and improve athletes' performance. Objective: To analyze knee's muscular performance of the knee extensors and flexors and lower limbs' functional performance of volleyball athletes. Methods: Fifteen female volleyball, athletes under the age of 16 from the University of Caxias do Sul, were analyzed. For analysis of muscle performance, the variables peak torque of knee extensors and flexors, and conventional flexor/extensor ratio, the isokinetic dynamometer was used. For the functional analysis of the lower limbs, the Hop tests and Y balance test (YBT) were used. Results: In the comparison between dominant (MD) and non-dominant (MND) limbs, there were no statistically significant differences in the analysis of peak torque; and in the flexor/extensor ratio analyzes, just one significant difference was found at 240°/s. However, the mean values of flexor/extensor ratio are below to the values suggested by the literature. Functional assessments also did not show asymmetries between members; however, the YBT composite score was below to the normative values. Conclusion: The excellent symmetry between the members can be justified by the sport's specificity, as the volleyball's gestures have a symmetrical character during the physical demands of the lower limbs. However, the low values of the flexor/extensor ratio and the YBT composite score may not be directly related to an increased risk of injuries since the reference values used are for adult athletes.

A influência de atividades de dupla tarefa na cinemática da marcha de indivíduos com hemiparesia espástica / The influence of dual task activities in the gait kinematics of individuals with spastic hemiparesis

Objetivo: analisar a influência de atividades de dupla tarefa na cinemática da marcha de indivíduos com hemiparesia espástica. Metodologia: amostra de 12 indivíduos, com idade entre 30 e 71 anos. Primeiramente, as tarefas simples foram realizadas: marcha simples (tarefa motora), tarefa de fluência verbal (tarefa cognitiva) e tarefa visuoespacial (tarefa cognitiva). Após, as duplas tarefas foram realizadas, onde foi realizada a marcha ao mesmo tempo das tarefas cognitivas. Para a avaliação da marcha, foi utilizado um sistema de captura da trajetória tridimensional da marcha e as variáveis estudadas foram cadência, velocidade, comprimento da passada, largura do passo, tempo da passada, apoio simples e apoio duplo. Para a análise dos resultados utilizou-se estatística descritiva, o teste t pareado e o teste de Correlação de Pearson (p<0,05). Resultados: na comparação com a marcha simples, durante as atividades de dupla tarefa os indivíduos apresentarem piores resultados nas variáveis cinemáticas da marcha. Durante a dupla tarefa de fluência verbal, as principais diferenças quando comparado com a marcha simples foram: velocidade, cadência, o tempo da passada, comprimento da passada e apoio simples. Já a dupla tarefa cognitiva visuoespacial demonstrou as principais diferenças na: velocidade, comprimento da passada e apoio simples. Houve correlação forte e significativa do Mini Exame do Estado Mental com a tarefa de fluência verbal simples e com a dupla tarefa; assim como para a tarefa visuoespacial simples e na dupla tarefa. Conclusão: conclui-se que ocorreu alteração em alguns parâmetros cinemáticos da marcha quando associado à dupla tarefa, com maior influência negativa da tarefa cognitiva de fluência verbal quando comparadas com a visuoespacial.

Objective: o analyze the influence of dual task activities on gait's kinematics in individuals with plastic hemiparesis. Methodology: included 12 individuals, aged between 30 and 71 years old. Firstly, simple tasks were performed: simple gait (motor task), verbal fluency task (cognitive task) and visuospatial task (cognitive task). Afterwards, the dual tasks were performed, where the gait was performed at the same time as the cognitive tasks. For gait assessment, a three-dimensional gait trajectory capture system was used and the variables studied were cadence, velocity, stride length, stride width, stride time, single support and double support. Descriptive statistics, paired t-test and Pearson's correlation test were used to analyze the results (p<0.05). Results: in comparison with single gait, during dual task activities, individuals showed worse results in gait's kinematic variables. During the dual task of verbal fluency and gait, the main differences when compared to simple gait were: velocity, cadence, stride time, stride length and simple support. Already visual-spatial cognitive task and gait demonstrated the main differences in: velocity stride length, simple support. There was a strong and significant correlation between Mini Mental State Examination with the simple verbal fluency task and with the double task; as well as for the simple visuospatial task and with the double task. Conclusion: it was concluded that modifications on some gait's kinematic parameters of gait occurred when associated with the double task, with a greater negative influence of the cognitive task of verbal fluency when compared with the visuospatial task.

A artrodese lombar e as alterações dos parâmetros espaço-temporais da marcha / Lumbar arthrodesis and the changes in spatiotemporal parameters of gait

As dores lombares podem causar frequentes incapacidades a longo prazo. O tratamento inicial de problemas lombares é realizado através de medicamentos e de fisioterapia; mas a cirurgia de artrodese também pode ser considerada para alguns casos específicos. Entretanto, acredita-se que a artrodese lombar pode afetar negativamente a marcha. O principal objetivo deste estudo foi identificar possíveis alterações nos parâmetros cinemáticos da marcha de indivíduos submetidos a artrodese lombar. Fizeram parte da amostra quinze indivíduos com médias de idade de 55,40 anos, de peso de 79,84 quilogramas, de altura de 1,60 metros e de tempo de pós operat ório de 59,33 meses. Um sistema de cinemetria capturou a trajetória tridimensional da marcha. Para a avaliação funcional, o questionário de Roland Morris (RMDQ) foi utilizado. O teste t para uma amostra foi utilizado para comparar com as variáveis da marcha com a normalidade; e o teste de correlação de Spearman, para verificar as correlações entre os parâmetros da marcha e o RMDQ, tempo de procedimento cirúrgico e idade. Os valores de velocidade (p < 0,0001), do comprimento da passada (p < 0,0001) e da largura do passo (p < 0,0001) apresentaram-se inferiores quando comparado aos valores normativos. Os resultados do questionário de RMDQ demonstraram que os participantes apresentaram níveis baixos de funcionalidade; com uma correlação forte e estatisticamente significativa (p < 0,05) entre a funcionalidade e a velocidade, cadência, tempo da passada e largura do passo. Resultados similares também foram encontrados em pacientes em tratamento conservador, demonstrando a falta de eficiência desse procedimento cirúrgico. Por isso, de ve-se questionar as reais necessidades da artrodese lombar, avaliando a gravidade e os objetivos de cada paciente com o intuito esgotar ao máximo as po ssibilidades de tratamento conservador antes da opção pela artrodese lombar. (AU)

Low back pain can cause frequent long-term disabilities. The initial treatment for low back problems is medication and physiotherapy; but arthrodesis surgery can also be considered for some specific cases. However, it is believed that lumbar arthrodesis can negatively affects gait. The main objective of this study was to identify possible changes in gait kinematic parameters after lumbar arthrodesis. Sample was composed by fifteen individuals with a mean age of 55.40 years, weighing 79.84 kilograms, height of 1.60 meters and postoperative time of 59.33 months. A kinematic system captured the three -dimensional trajectory of the gait. For functionality evaluation, the Roland-Morris Disability Questionnaire (RMDQ) was used. The t-test for one sample was used to compare gait variables with normality; and the Spearman correlation test was used to verify the correlations between gait par ameters and RMDQ, surgical time and age. The values of velocity (p < 0.0001), stride length (p < 0.0001) and step width (p < 0.0001) were lower when compared to normative values. The results of the RMDQ showed that participants had low levels of functionality; with a strong and statistically significant correlation (p < 0.05) between functionality and velocity, between functionality and cadence, between functionality and stride time, and between functionality and stride widt h. Similar results were also found in patients under conservative treatment, demonstrating this surgical procedure is inefficiency. Therefore, should be asked the real needed for lumbar arthrodesis, measuring the severity and objectives of each patient in order to fully exhaust the possibilities of conservative treatment b efore opting for lumbar arthrodesis. (AU)

Análise cinemática da marcha pós protocolo de fadiga global de curta duração / Kinematic gait analysis post short-term global fatigue protocol

OBJETIVO: Avaliar os efeitos de um protocolo de fadiga global de curta duração sobre os parâmetros cinemáticos da marcha de indivíduos saudáveis. MÉTODOS: Fizeram parte da amostra 21 adultos jovens saudáveis. Foi realizada a análise de parâmetros da cinemática linear (velocidade, cadência, comprimento do passo, largura do passo e tempo do passo) e angular da marcha (flexão e extensão dos quadris; flexão e extensão dos joelhos; plantiflexão e dorsiflexão dos tornozelos) antes e após a realização de um protocolo de fadiga global de curta duração. Para a avaliação da marcha, foi utilizado um sistema de captura da trajetória tridimensional da marcha, composto por um sistema de cinemetria dotado de 7 câmeras integradas. O Protocolo de Fadiga de Agilidade Funcional de Curta Duração, que consiste em um protocolo de fadiga global de curta duração com séries de exercícios de agilidade funcional, foi utilizado para fadigar os participantes. Para as comparações entre as avaliações pré e pós-fadiga, os valores médios de cada avaliação foram utilizados e submetidos ao teste t pareado, e nível de significância adotado foi p<0,05. RESULTADOS: Não houveram diferenças estatisticamente significativas nos parâmetros angulares e lineares avaliados, exceto para cadência (p=0,03). CONCLUSÕES: O protocolo de fadiga global de curta duração não alterou os parâmetros angulares e cinemáticos da marcha em indivíduos jovens, exceto a cadência que se mostrou mais elevada após o protocolo de fadiga.

AIMS: Evaluate the effects of a short-term fatigue protocol on gait's kinematic parameters of healthy subjects. METHODS: 21 healthy young adults participated in the sample. The parameters of linear kinematics of gait (velocity, cadence, step length, step width, step time) and angular kinematics of gait (hip's flexion and extension; knee's flexion and extension; ankle's dorsiflexion and plantar flexion) were analyzed before and after performing a short-term fatigue protocol. For gait evaluation, a three-dimensional gait trajectory capture system was used, consisting of a kinematic system with 7 integrated cameras. The Short-Term Functional Agility Fatigue Protocol, which consists of a short-term global fatigue protocol with series of functional agility exercises, was used to fatigue participants. For comparisons between pre and post fatigue evaluations, the mean values to paired t test, and statistical significance was set as p<0.05. RESULTS: There were no statistically significant differences in the angular and linear parameters evaluated, except for cadence (p=0.03). CONCLUSIONS: The short-term global fatigue protocol did not alter the angular and kinematic gait parameters in young subjects, except for the cadence, that was higher after the fatigue protocol.