Comparison of spatiotemporal and angular parameters during shallow water walking in different immersion depths by older adults with and without Parkinson's disease.

BACKGROUND: People with Parkinson's Disease (PwPD) have motor symptoms that directly interfere on dry land walking performance. Despite the shallow water walking is a viable and beneficial physical intervention for PwPD, it lacks information on the comparison of the biomechanical responses of the shallow water walking by PwPD and age paired healthy individuals. RESEARCH QUESTION: Are there differences in the spatiotemporal and angular responses of shallow water walking by older adults with and without Parkinson's disease? METHODS: In this cross-sectional study, ten older adults (9 men/1 women) with Parkinson disease (PwPD group) and ten older adults (3 men/7 women) without Parkinson's disease (Older group) walked in shallow water at self-selected comfortable speed on pool floor in the immersion depths of waist and xiphoid levels. The 2D kinematic data from the sagittal plane was collected to calculate the walking speed, stride length, stride frequency, duty factor, walk ratio, lower limb joints' range of motion and peak angular speed RESULTS: Both groups reduced similarly the walking speed with the immersion depth increase. The speed decrease was achieved by a reducing both the stride frequency and stride length only in the PwPD. The PwPD had lower contact phase than Older in the waist depth, probably due to the reduced risk of fall in water immersion and to attenuate drag force effects. The total range of joint motion was similar between groups, while the peak angular speed of ankle and knee reduced in the deeper depth in both groups. SIGNIFICANCE: The present findings can help professionals of aquatic rehabilitation to choose the best depth for exercise programs, according to the treatment objectives. To our knowledge, this was the first study that analyzed spatiotemporal and angular variables during shallow water walking of PwPD at different depths and compared them with older people without Parkinson's disease.

Observational evidence of the association between physical and psychological determinants of aging with cognition in older adults.

Aging involves physical and cognitive deterioration in older adults. Detecting predictors of dementia early is crucial to identify its onset. This study aimed to associate physical and psychological determinants with cognitive performance in older adults. Observational study with 221 older adults, classified according to cognitive impairment. We evaluated cognitive function by Mini-Mental State Examination. Physical determinants encompassed muscle strength, functional mobility, and cardiorespiratory fitness, while psychological consisted of quality of life and activities of daily living. Multiple linear regression was performed to investigate this relationship. Physical and psychological determinants were significantly linked to cognitive impairment, including lower muscle strength, reduced functional mobility and of cardiorespiratory fitness. The influence of environment, autonomy, and engagement in daily activities on cognitive impairment was also observed. The analysis of physical and psychological determinants could help to aid in distinguishing individuals with cognitive impairment.

Postural adjustments and perceptual responses of Nordic running: concurrent effects of poles and irregular terrain.

PURPOSE: In the natural environment, humans must continuously negotiate irregular and unpredictable terrain. Recently, the poles have been extensively used during trial running events. However, we know little about how humans adjust posture and bilateral coordination to use poles in irregular terrain. Here, we compared kinematics, bilateral coordination and perceptual responses between regular (compact dust) and irregular terrain (medium-length grass) during running at preferred speed with and without poles. METHODS: In this transversal observational study, thirteen young healthy adults (8 men; mean ± SD; age 29.1 ± 8.0 years, body mass 76.8 ± 11.4 kg; height 1.75 ± 0.08 m) were evaluated during running at a self-selected comfortable speed with and without poles on regular and irregular terrains. RESULTS: Our results show that, despite more flexed pattern on lower-limb joints at irregular terrain, the usage of poles was not enough to re-stabilize the bilateral coordination. Also, the perceived exertion was impaired adding poles to running, probably due to more complex movement pattern using poles in comparison to free running, and the invariance in the bilateral coordination. CONCLUSION: Besides the invariability of usage poles on bilateral coordination and lower-limb kinematics, the runners seem to prioritize postural stability over lower limb stiffness when running in medium-length grass given the larger range of ankle and knee motion observed in irregular terrain. Further investigations at rougher/hilly terrains will likely provide additional insights into the neuromotor control strategies used to maintain the stability and on perceptual responses using poles during running.

The effects of Brazilian dance, deep-water exercise and nordic walking, pre- and post-12 weeks, on functional-motor and non-motor symptoms in trained PwPD.

BACKGROUND: Motor and non-motor symptoms affect functional autonomy, mobility and daily life activities in People with Parkinson's Disease (PwPD). Brazilian Dance (BD), Deep-water exercise (DWE), and Nordic Walking (NW) are well-accepted, low-cost, and safe non-pharmacological strategies for untrained PwPD. However, no previous studies have investigated and compared the effects of these interventions on trained PwPD. OBJECTIVE: To describe and compare the effects of BD, DWE and NW, pre- and post-12 weeks, on functional-motor and non-motor symptoms in trained PwPD. METHODS: Eighty-three trained PwPD were randomly assigned into three groups: BD (n = 31), DWE (n = 21) and NW (n = 31), that participated in one of the interventions for 12 weeks. We applied Timed up and go at two speeds (self-selected and fast); 6-min and 10-meter walk test; Sit-to-Stand and handgrip test; Unified Parkinson Disease Rating Scale - III; Falls Efficacy Scale; Montreal Cognitive Assessment questionnaire; and Parkinson's Disease Questionnaire-39. The main (group and time) and interaction effects were analyzed using GEE analysis (p<0.05). RESULTS: Statistical differences were found between groups in the handgrip test (p<0.01), the time (p = 0.04), and interaction group*time (p< 0.01) in the Sit-to-stand test. While BD improved the Sit-to-stand test performance (ES=1.00; large effect size), DWE and NW remained unchanged (ES=0.16 and ES=0.14; low effect size). CONCLUSION: BD, DWE, and NW maintained most of the functional-motor and non-motor symptoms in trained PwPD. BD was shown to be more effective at improving strength in the lower limbs, when compared to NW and DWE.

Pendular mechanism determinants and elastic energy usage during walking of obese and non-obese children.

The mechanical and metabolic responses of walking by obese children are not yet well understood. The objectives of this study were (1) to compare the pendular mechanism (recovery, phase shift by α and ß values, and ratio between forward and vertical mechanical work), the maximum possible elastic energy usage and the bilateral coordination during walking between non-obese and obese children, and (2) to verify if the bilateral coordination could contribute to understanding the pendular mechanism and elastic energy usage in these populations. Nine obese (six female, 8.7 ± 0.5 years, 1.38 ± 0.04 m, 44.4 ± 6.3 kg and 24.1 ± 3.50 kg/m2 ) and eight non-obese (four female, 7.4 ± 0.5 years, 1.31 ± 0.08 m, 26.6 ± 2.1 kg and 16.4 ± 1.40 kg/m2 ) children were analysed during walking on a treadmill at five speeds: 1, 2, 3, 4 and 5 km/h. The results indicated that although the mechanical energy response of the centre of mass during walking is similar between obese and non-obese children, the obese children showed a lower pendulum-like mechanism and greater elastic energy usage during level walking. Therefore, obese children seem to use more elastic energy during walking compared to non-obese children, which may be related to their apparent higher positive work production during the double support phase. Finally, bilateral coordination presented high values at slow speeds in both groups and requires further attention due to its association with falls. NEW FINDINGS: What is the central question of this study? Are there any differences of the pendular and elastic mechanisms and bilateral coordination during walking between non-obese and obese children? What is the main finding and its importance? To our knowledge, this study is the first to analyse the mechanical energy usage and the bilateral coordination of obese and non-obese children during walking. Obese children had a lower pendular recovery mechanism and used more elastic energy compared to non-obese children. The bilateral coordination was higher at slow speeds in both groups and requires further attention due to its association with falls.

Determinants of Dual-task Gait Speed in Older Adults with and without Parkinson's Disease.

Mobility difficulties for people with Parkinson's disease (PwPD) are more pronounced when they perform a simultaneous cognitive task while walking. Although it is known that neurodegeneration results in widespread motor and brain impairments, few studies have comprehensively examined possible physical and mental determinants of dual task walking in PwPD. In this cross-sectional study, we aimed to investigate if and how muscle strength (sit-to-stand 30-sec test), cognition (mini-mental state examination) and functionality (timed up and go test) affect walking performance (10-meter walking test) with and without arithmetic dual task from older adults with and without Parkinson's disease. Walking speed was reduced by 16% and 11% with arithmetic dual task for PwPD (from 1.07±0.28 to 0.91±0.29 m.s-1, p<0.001) and older adults (from 1.32±0.28 to 1.16±0.26 m.s-1, p=0.002) compared to essential walking. The cognitive state was similar among the groups, but it was only associated with the dual-task walking speed in PwPD. In PwPD, lower limb strength was the better predictor of speed, whereas mobility was more related to it in older adults. Therefore, future exercise interventions aiming to improve walking in PwPD should consider these findings to maximize their effectiveness.

Effects of aging on arm coordination at different walking speeds.

BACKGROUND: Previous work has shown that the mean continuous relative phase and coordination variability of lower limbs are modified in older adults when walking. RESEARCH QUESTION: Here, we propose to understand the extent to which such control mechanisms for upper limbs are present during gait. Specifically, we seek to understand if aging and gait speed constraints influence the interjoint control of upper limbs during walking. METHODS: This observational study evaluated thirty-three participants, divided into older (n = 20, age 66.4 ± 4.3 years; mass: 77.2 ± 14.2 kg; height: 165 ± 9.20 cm) and young adults (n = 13, age 29.5 ± 4.7 years; mass 75.5 ± 9.6 kg; height: 172 ± 6.24 cm) were asked to walk at 0.28, 0.83, 1.38 m.s-1 on a level treadmill while their segmental movements were simultaneously registered with 3D motion capture system. We calculated the mean continuous relative phase and coordination variability (continuous relative phase variability) in elbow-shoulder and shoulder-hip pairs, and a generalized estimating equation was used to test the main and interaction effects of age and speed. RESULTS: Older adults had a reduced continuous relative phase (more in-phase coordination) of upper limbs at whole stance for elbow-shoulder, at loading response for shoulder-hip, at mid-stance and terminal stance for elbow-shoulder and shoulder-hip in comparison to young adults at different speeds (p < 0.05). The coordination variability of upper limbs was greater (higher continuous relative phase variability) in older than young adults at 0.28 and 1.38 m.s-1. SIGNIFICANCE: These findings substantiate the altered motor control role of upper limbs in gait aging, suggesting that lower self-selected speed may be related to the reduced ability to control arm movement during the intermediate phases of gait.

Quantifying physiological and biomechanical responses of shallow water walking: a systematic review and meta-analysis.

Detecting the physiological and biomechanical alterations in shallow water walking (SWW) due to water depth and speed is important for health professionals to perform accurate exercise prescription. This systematic review with meta-analysis aimed to investigate the acute physiological and biomechanical responses of SWW at different immersion depths in comparison to dry land walking. The main result (initial search: 1960 studies; systematic review: 42 studies; meta-analysis: 22 studies) indicated that metabolic power was higher in the immersion depth levels of xiphoid process (standardized mean differences (SMD) = 0.90; 95% confidence intervals (CI): 0.26 to 1.54) and waist (SMD = 3.35; 95% CI: -0.18 to 6.87) in comparison to dry land. SWW at xiphoid and waist depths seems to be an adequate exercise if the objective is to increase the energy expenditure and cardiovascular demand while the lower limb impact forces are reduced in comparison to dry land walking. PROSPERO registration: CRD42018113040.

Biomechanical responses of Nordic walking in people with Parkinson's disease.

In healthy adults, Nordic walking (NW) is known to increase the external mechanical energy fluctuations, though the external work is unaltered due to an improved pendulum-like recovery in comparison with free walking (FW). We aimed to compare mechanical, pendulum-like, and spatiotemporal parameters of gait at different speeds with and without NW poles in people with Parkinson's disease and healthy controls. The study included 11 people (aged 65.6 ± 7.0 years) with idiopathic Parkinson's disease, scoring between 1 and 1.5 on the Hoehn and Yahr scale (H&Y), and nine healthy controls (aged 70.0 ± 5.6 years). All the people were experienced Nordic walkers. Walking tests were performed at 1.8 km h-1 and 4.7 km h-1 , on eight 3D force platforms on a walkway. We found greater pendulum-like energy recovery (p < 0.05) in the Parkinson group during NW than in FW, while external mechanical work remained similar (p > 0.05). People with Parkinson's disease showed a major increase in vertical and forward energy fluctuations using poles than in healthy controls. In addition, the Parkinson group showed increased stride frequency and reduced stride length compared to controls in the NW and FW conditions. Our findings partly justify the lower walking economy in Parkinson's disease due to reduced pendulum-like mechanism at commonly used speeds. NW alters gait mechanics similarly in Parkinson group and healthy control, increasing the total mechanical work. Therefore, NW can be a compelling strategy for rehabilitation because of its potential for improving functional mobility, increasing pendulum-like mechanism in Parkinson's disease.

Postural Adjustments and Biomechanics During Gait Initiation and Obstacle Negotiation: A Comparison Between Akinetic-Rigid and Hyperkinetic Parkinson's Disease.

Background: Individuals with Parkinson's disease (PD) exhibit different combinations of motor symptoms. The most frequent subtypes are akinetic-rigid (AK-R) and hyperkinetic (HYP). Motor symptoms, such as rigidity and bradykinesia, can directly affect postural adjustments and performance in daily tasks, like gait initiation and obstacles negotiation, increasing the risk of falls and functional dependence. Objective: To compare postural adjustments and biomechanical parameters during the gait initiation and obstacle negotiation of people with AK-R and HYP PD and correlate with functional mobility and risk of falls. Methods: Cross-sectional study. Thirty-three volunteers with PD were divided into two groups according to clinical motor manifestations: AK-R (n = 16) and HYP (n = 17). We assessed the anticipatory (APA), compensatory (CPA) postural adjustments analyzing kinematic, kinetic and, electromyographic parameters during the gait initiation and obstacle negotiation tests. We applied independent T-tests and Pearson correlation tests for comparisons and correlations, respectively (α = 0.05). Results: In the APA phase of the gait initiation test, compared to the functional HYP group, the AK-R group showed shorter time for single support (p = 0.01), longer time for double support (p = 0.01) accompanied by a smaller first step (size, p = 0.05; height, p = 0.04), and reduced muscle activation of obliquus internus (p = 0.02). Similarly, during the first step in the obstacle negotiation test, the AK-R group showed less step height (p = 0.01) and hip excursion (p = 0.02), accompanied by a reduced mediolateral displacement of the center of pressure (p = 0.02) during APA, and activation of the gluteus medius (p = 0.02) and the anterior tibialis (p = 0.04) during CPA in comparison with HYP group. Conclusion: The findings suggest that people with AK-R present impaired postural adjustments during gait initiation and obstacles negotiation compared to hyperkinetic PD. Based on defined motor symptoms, the proposition presented here revealed consistent postural adjustments during complex tasks and, therefore, may offer new insights onto PD motor evaluation and neurorehabilitation.

Effect of exercise and grape juice on epigenetic modulation and functional outcomes in PD: A randomized clinical trial.

OBJECTIVE: This study aimed to investigate the impact of an aquatic physical training program associated with grape juice (Vitis labrusca) consumption on functional outcomes, Brain-Derived Neurotrophic Factor (BDNF) and global histone H4 acetylation levels in peripheral blood from individuals with Parkinson's disease. METHODS: Nineteen participants were randomized to Aquatic Exercise (AQ, n = 9) and Aquatic Exercise + Grape Juice (AQ+GJ, n = 10) groups and performed to 4 weeks of an aquatic intervention (twice a week, approximately 60 min/session). The AQ+GJ groups also consumed 400 mL of grape juice per day during this period. Functional capacity (six-min walk test, 6MWT), mobility (The Timed Up and Go, TUG) and the risk of falls (Berg Balance Scale, BBS) were evaluated before and after intervention. In addition, blood collections were carried out for biomarker analysis (e.g. BDNF and global histone H4). RESULTS: The aquatic exercise program induced functional improvement in individuals with Parkinson's disease, specifically ameliorating their mobility and functional capacity. In addition, enhanced levels of BDNF and histone H4 acetylation were found after the intervention. Grape juice consumption did not potentiate these effects, since any significant differences between the AQ and AQ+GJ groups were not found in all analysed variables. CONCLUSIONS: The present study provides important insights about aquatic exercise-modulated BDNF levels in individuals with Parkinson's disease in combination with functional improvements, suggesting that histone acetylation status may interact to dictate the molecular mechanisms involved in this response. Parkinson disease, aquatic exercise, BDNF, epigenetic, grape juice.

A 9-Week Nordic and Free Walking Improve Postural Balance in Parkinson's Disease.

Aerobic training has a neuroprotective effect in people with Parkinson's disease. Recent evidence indicates that Nordic walking seems a promising alternative due to positive outcomes in functional mobility. However, the effects of Nordic walking compared to free walking on static and functional balance parameters are still unknown. The aim of this study was to evaluate the effects of nine weeks of Nordic and free walking training on static and functional balance. The sample size was 33 individuals with eight dropouts, leaving 25 individuals in the final sample (Nordic Walking, n=14, Free Walking, n=11). The participants underwent two evaluations in the present randomized clinical trial, pre- and post-training, to determine average velocity and root-mean-square values from center of pressure with eyes open and eyes closed. The functional balance showed approximately 5% improvement for the two groups ( p =0.04). The results indicate that nine weeks of Nordic and free walking training were enough to induce improvements in the proprioceptive system and functional balance.

Aspectos biomecânicos da locomoção de pessoas com doença de Parkinson: revisão narrativa / Biomechanical aspects of locomotion people with Parkinson's disease: review study / Aspectos biomecánicos de la locomoción de personas con enfermedad de Parkinson: una revisión

Resumo A presente revisão narrativa tem por objetivo analisar os aspectos biomecânicos da locomoção e os efeitos de intervenções nos padrões da marcha de pessoas com doença de Parkinson (DP). Fez-se uma pesquisa bibliográfica no banco de dados dos sistemas SciELO e PubMed, com as seguintes palavras: human locomotion, biomechanics, pathologic gait e Parkinson's disease, em periódicos nacionais e internacionais. Concluímos que as principais alterações biomecânicas são nos parâmetros espaçotemporais, como menor comprimento de passada e estabilidade dinâmica, além da baixa ativação muscular nos músculos propulsores, bem como menor velocidade autosselecionada da marcha. Fazem-se necessários protocolos de treinamento de caminhada que considerem esses parâmetros para auxiliar a reabilitação da marcha de pessoas com DP.

Abstract The purpose of this review was to analyze the biomechanical aspects of walking in individuals with Parkinson's disease (PD), as well as to examine the effects of intervention on gait pattern of PD. We carried out a bibliographic search on electronic databases SciELO and PubMed, using the following words: human locomotion, biomechanics, pathologic gait e Parkinson's disease, in national and international scientific journals. The main alterations on walking biomechanics are related to spatiotemporal parameters, lower stride length and dynamical stability, as well as reduced electromyographic activation on propulsion muscles and lower self-selected speed. These outcomes seem to be important targets in walking training protocols for rehabilitation of gait in PD.

Resumen La presente revisión tiene por objetivo analizar los aspectos biomecánicos de la locomoción y los efectos de las intervenciones en los patrones de la marcha en personas con enfermedad de Parkinson (EP). Se realizó una investigación bibliográfica en las bases de datos SciELO y PubMed, utilizando las siguientes palabras:human locomotion, biomechanics, pathologic gait y Parkinson's disease, en revistas nacionales e internacionales indexadas. Se llegó a la conclusión de que las principales alteraciones biomecánicas se encuentran en los parámetros espacio-temporales, como menor longitud de la zancada y estabilidad dinámica, además de una baja activación electromiográfica de los músculos propulsores, como menor velocidad autoseleccionada de la marcha. Estos resultados convierten en necesarios protocolos de entrenamiento de la marcha que tengan en cuenta estos parámetros para la rehabilitación de personas con EP.

Non-invasive interventions in idiopathic scoliosis: a systematic review / Intervenções não invasivas na escoliose idiopática: revisão sistemática

Abstract Introduction: Idiopathic Scoliosis (IS) is an idiopathic curvature of the spine in all three plans, been treated conservatively (non-invasive) or surgicaly (invasive). The effectiveness of noninvasive therapy still remains lacking in a scientific basis to support their evidence-based applicability. Objective: Evaluate the effects of non-invasive interventions in spine lateral inclination in IS through a systematic literature review. Methods: The search of studies in MEDLINE, SCOPUS and COCHRANE databases was performed on 24th March, 2014. The terms used were: Scoliosis, therapeutic exercise, physical therapy. Clinical trials with scoliotic patients undergoing some type of non-invasive intervention were included. The outcome was spine lateral inclination. Results: The research found 941 studies, seven of these were included after a screening performed by two independent reviewers. Six studies (85.7%) have adopted some sort of kinesiotherapeutic technic, and three studies (42.8%) used corrective orthosis. The average intervention time in kinesiotherapeutic technique studies was of 37.6 weeks and 91.6 weeks in the studies of corrective brace. The progression improvement of the spine lateral inclination was reported by 83.3% (5 of 6) of the kinesiotherapeutic technique studies and in 66.6% (2 of 3) of studies with corrective brace. Conclusion: An improvement was found, in general, in the progression of spine lateral inclination in IS subjects of both sexes from 11 to 25 years of age undergoing non-invasive interventions.

Resumo Introdução: A Escoliose Idiopática (IS) é uma curvatura idiopática da coluna vertebral nos três planos de tratamento conservador (não invasivo) ou cirúrgico (invasivo). Ainda assim, a efetividade da terapêutica não invasiva permanece carente de um embasamento científico que suporte sua aplicabilidade baseada em evidências. Objetivo: avaliar os efeitos de intervenções não invasivas sobre inclinação lateral da coluna IS por meio de uma revisão sistemática da literatura. Métodos: Foi realizada uma busca de estudos nas bases de dados MEDLINE, SCOPUS e COCHRANE, em 24 de março de 2014. Os termos utilizados foram: scoliosis, exercise therapy, physiotherapy, physical therapy. Foram incluídos ensaios clínicos com indivíduos escolióticos submetidos a algum tipo de intervenção não invasiva. O desfecho incluído foi inclinação lateral da coluna. Resultados: A busca inicial resultou em 941 estudos, com 07 estudos incluídos após triagem de dois revisores independentes. Seis estudos (85,7%) adotaram algum tipo de técnica cinesioterapêutica, e três estudos (42,8%) valeram-se do uso de órtese corretiva. O tempo de intervenção médio nos estudos com técnica cinesioterapêutica foi de 37,6 semanas, e de 91,6 semanas nos estudos com órtese corretiva. A melhora na progressão da inclinação lateral da coluna foi relatada em 83,3% (5 de 6) dos estudos com técnica cinesioterapêutica, e em 66,6% (2 de 3) dos estudos com órtese corretiva. Conclusão: Foi encontrada uma melhora, de maneira geral, na progressão da inclinação lateral da coluna na IS em sujeitos de ambos os sexos de 11 a 25 anos de idade submetidos a intervenções não invasivas.

Efeitos da fadiga muscular induzida por exercícios no tempo de reação muscular dos fibulares em indivíduos sadios / Effects of the exercise-induced muscular fatigue on the time of muscular reaction of the fibularis in healthy individuals

A fadiga muscular (FM) é um fenômeno comum nas atividades esportivas e diárias, resultando numa piora da performance motora. Ela é considerada um dos fatores causadores de lesões músculo-esqueléticas. A entorse de tornozelo é um exemplo: a FM afetaria tanto o sistema aferente quanto o eferente. Vários estudos têm analisado a influência da FM no controle neuromuscular (CNM); entretanto, existe pouca pesquisa sobre essa influência na velocidade de reação dos músculos. O objetivo deste estudo foi verificar os efeitos da FM no tempo de reação muscular (TRM) dos músculos fibulares, que são os primeiros a responder a um estresse em inversão do tornozelo. Foram estudados 14 indivíduos saudáveis masculinos (idade: 20-35 anos), que tiveram seus TRM avaliados por meio de eletromiografia (EMG) de superfície. O início da atividade muscular foi definido como a média de repouso + 3x o desvio-padrão (DP). O TRM dos fibulares foi mensurado após uma inversão súbita de 20° realizada numa plataforma. A inversão súbita foi realizada antes e depois da fadiga muscular, que foi induzida por exercícios localizados dos fibulares até a exaustão. Os resultados mostraram que houve um aumento significativo do tempo de reação muscular após a fadiga (p < 0,01). Durante atividades esportivas prolongadas e durante o processo de reabilitação, deve-se ter cautela na realização de tarefas que requeiram respostas musculares extremamente rápidas sob condições de fadiga muscular.

The muscular fatigue (MF) is a common phenomenon in the daily sports activities that results in a worsening of the motor performance. It is considered one of the major factors for muscle-skeletal damages, such as the ankle sprain, when the MF would affect both the afferent and the efferent systems. Several studies have been analyzing the influence of the MF on the neuromuscular control (NMC). Nevertheless, there are few researches comprising that influence on the velocity of the muscular reaction. The purpose of this study was to check the effects of the MF on the time of the muscular reaction (TMR) in the fibularis muscles, which are the first to respond to an inversion stress of the ankle. Fourteen healthy male individuals (age: 20-35 years) were studied, who had their TMR assessed by means of the surface electromyography (EMG). The beginning of the muscular activity was defined as the mean resting value +3x the standard deviation (SD). The TMR of the fibularis was measured after a sudden 20° inversion performed on a platform. The sudden inversion was performed before and after the muscular fatigue, which was induced through localized exercises of the fibularis up to the exhaustion. The results have shown a significant increase in the time of the muscular reaction after the fatigue (p < 0.01). While performing prolonged sportive activities and during the rehabilitation process, there must be caution to perform tasks that require extremely fast muscular responses.

La fatiga muscular (FM) es un fenómeno común en las actividades diarias, produciendo un empeoramiento de la actuación. Se la considera una de las causas de factores lesionantes musculares de esqueleto. El esguince del tobillo es un ejemplo: La FM afectaría tanto el sistema aferente cuanto el eferente. Varios estudios han estado analizando la influencia de FM en el comando neuromuscular (CNM), sin embargo, la existen pocas investigaciones sobre la influencia en la velocidad de reacción de los músculos. El objetivo de ese estudio era verificar los efectos de FM en el tiempo de reacción muscular (TRM) de los músculos peroneos, que son los primeros en responder a una tensión en la inversión del tobillo. Se estudiaron 14 individuos saludables masculinos (con edad: entre 20-35 años), que tenían su TRM estimado a través de la eletromiografia (EMG) de superficie. El principio de la actividad muscular se definió como el promedio del resto + 3x la desviación normal (DP). TRM de músculos peroneos estava moderado después de una inversión súbita de 20° cumplida en una plataforma. La inversión súbita se realizaba antes y después de la fatiga muscular, que era inducido por los ejercicios localizados en los músculos peróneos hasta agotamiento. Los resultados mostraron que había un aumento significante del tiempo de reacción muscular después de la fatiga (p < 0.01). Durante las actividades deportivas y durante el proceso de la rehabilitación, debe tenerse cautela en la realización de las tareas que se solicitan como respuestas musculares sumamente rápidas bajo las condiciones de fatiga muscular.

Análise eletromiográfica do quadríceps durante a extensão do joelho em diferentes velocidades / Electromyographical analysis of the quadriceps during knee extension at different speeds

A síndrome de dor fêmuro-patelar (SDFP) é uma disfunção comum, geralmente causada por trações laterais excessivas da patela. Indivíduos com SDFP, usualmente apresentam inibição do vasto medial oblíquo (VMO), o qual é responsável pela tração medial patelar. O tratamento conservador envolve o reforço do quadríceps para promover melhor estabilidade e tração patelar. Muitos pesquisadores buscam o recrutamento seletivo do VMO, com o intuito de otimizar o tratamento. O objetivo deste estudo é investigar, através da eletromiografia, a interferência da velocidade angular e diferentes formas de fixação do tubo elástico na atividade quadricipital. Dez indivíduos do sexo masculino com ausência de lesão muscular ou articular participaram deste estudo. Indivíduos com ângulo Q fora do intervalo de 10-15° foram excluídos da pesquisa. O tubo elástico foi fixado paralelo e oblíquo em relação ao corpo do indivíduo. As extensões de joelho foram realizadas com velocidades angulares de 60 e 120°/seg. Nenhuma atividade seletiva do VMO foi encontrada. Comparando os níveis de atividade muscular, durante as duas velocidades angulares houve aumento no nível de atividade eletromiográfica em todas porções do quadríceps, apenas para a fixação do tubo elástico paralela. Os resultados sugerem uma atividade sinérgica entre o VMO e as outras porções do quadríceps.