Reciprocal Inhibition and Coactivation of Ankle Muscles in Low- and High-Velocity Forward and Backward Perturbations.

Reciprocal inhibition and coactivation are strategies of the central nervous system used to perform various daily tasks. In automatic postural responses (APR), coactivation is widely investigated in the ankle joint muscles, however reciprocal inhibition, although clear in manipulative motor actions, has not been investigated in the context of APRs. The aim was to identify whether reciprocal inhibition can be observed as a strategy in the recruitment of gastrocnemius Medialis (GM), Soleus (So) and Tibialis Anterior (TA) muscles in low- and high-velocity forward and backward perturbations. We applied two balance perturbations with a low and a high velocity of displacement of the movable platform in forward and backward conditions and we evaluated the magnitude and latency time of TA, GM and So activation latency, measured by electromyography (EMG). In forward perturbations, coactivation of the three muscles was observed, with greater activation amplitude of the GM and lesser amplitude of the So and TA muscles. For backward, the pattern of response observed was activation of the TA muscle, a decrease in the EMG signal, which characterizes reciprocal inhibition of the GM muscle and maintenance of the basal state of the So muscle. This result indicates that backward perturbations are more challenging.

Muscular and Kinematic Responses to Unexpected Translational Balance Perturbation: A Pilot Study in Healthy Young Adults.

Falls and fall-related injuries are significant public health problems in older adults. While balance-controlling strategies have been extensively researched, there is still a lack of understanding regarding how fast the lower-limb muscles contract and coordinate in response to a sudden loss of standing balance. Therefore, this pilot study aims to investigate the speed and timing patterns of multiple joint/muscles' activities among the different challenges in standing balance. Twelve healthy young subjects were recruited, and they received unexpected translational balance perturbations with randomized intensities and directions. Electromyographical (EMG) and mechanomyographical (MMG) signals of eight dominant-leg's muscles, dominant-leg's three-dimensional (3D) hip/knee/ankle joint angles, and 3D postural sways were concurrently collected. Two-way ANOVAs were used to examine the difference in timing and speed of the collected signals among muscles/joint motions and among perturbation intensities. This study has found that (1) agonist muscles resisting the induced postural sway tended to activate more rapidly than the antagonist muscles, and ankle muscles contributed the most with the fastest rate of response; (2) voluntary corrective lower-limb joint motions and postural sways could occur as early as the perturbation-induced passive ones; (3) muscles reacted more rapidly under a larger perturbation intensity, while the joint motions or postural sways did not. These findings expand the current knowledge on standing-balance-controlling mechanisms and may potentially provide more insights for developing future fall-prevention strategies in daily life.

Low back pain leads to a protective action of pain on dynamic postural stability.

Low back pain (LBP) is a painful manifestation in the lower part of the spine which causes disabilities changing the sensitivity of sensory neurons resulting in weakness of postural muscles interfering with the balance. It is not already clear if LBP people's muscle changes affect the centre of pressure (CoP) recovery in challenging stance perturbations. The aim of this study was to identify differences in the muscle reactions of people with and without LBP to control CoP in challenging stance perturbations. We applied low (Vel1) and high (Vel2) magnitude stance perturbation by a movable platform and evaluated (a) the magnitude and latency time of trunk and lower limb muscle activation, (b) and the displacement and the latency time of the first CoP peak. The latency of trunk and hip muscle activation on Vel2 was lower for LBP group. The CoP latency and displacement did not change between groups and velocities indicating that the muscles took the same time to overcome the external forces. In conclusion, the maintenance of CoP latency at both velocities was not affected on Vel2, suggesting that such alterations have protective action and preservation of the pain on the LPB group in challenging stance perturbations.

Influence of the Coach's Method and Leadership Profile on the Positive Development of Young Players in Team Sports.

In a time of instability caused by adolescence, sport may represent a resource to prevent future individual and social problems. Within the complex relationships developed in social sports contexts, the figure of the coach can be fundamental for the development of a beneficial environment. The objective of the research was to investigate the relationship between the teaching methods and leadership profile of the coach and outcomes on the perception of positive development of young people participating in an after school sports program. In total participated, 910 adolescents (14.0 ± 1.8 years) and 57 coaches (45.57 ± 7.25 years) in 37 public schools in the city of Curitiba, in the state of Paraná-Brazil. Ordinal logistic regression was used to verify the independent associations between the variables sex, category, sport, trainer methodology, perception of the coaches, and perception of the athletes with the tertiles of the scores of each developmental characteristic of the young athletes (personal and social skills, cognitive skills, goal setting, and initiative). Odds ratios (OR) were obtained with a 95% confidence interval (95%CI), adopting p < 0.05. The small sized games method were positively associated with cognitive skills and goal setting. Positive associations were also found between athletes' perceptions of the leadership profile of coaches with: personal and social skills (instructor, democratic behaviour, social support, and positive feedback), cognitive skills (instructor, democratic behaviour, and social support), goal setting (instructor, social support, and positive feedback), and initiative (instructor and positive feedback). In addition, the athletes' perception of the coaches' autocratic behaviour was inversely associated with personal and social skills and goal setting. For the evaluated program, the results suggest the choice, on the part of the coaches, of small sized games, combined with a democratic, affective, motivating leadership profile that provides instructions on technical skills and game strategies. The combination of the designated psych-pedagogical aspects is correlated to the positive development of young people through team sports.

Compensatory control between the legs in automatic postural responses to stance perturbations under single-leg fatigue.

In response to sudden perturbations of stance stability, muscles of both legs are activated for balance recovery. In conditions that one of the legs has a reduced capacity to respond, the opposite leg is predicted to compensate by responding more powerfully to restore stable upright stance. In this investigation, we aimed to evaluate between-leg compensatory control in automatic postural responses to sudden perturbations in a situation in which plantar flexor muscles of a single leg were fatigued. Young participants were evaluated in response to a series of perturbations inducing forward body sway, with a focus on activation of plantar flexor muscles: lateral and medial gastrocnemii and soleus. Muscular responses were analyzed through activation magnitude and latency of muscular activation onset. For evaluation of balance and postural stability, we also analyzed the center of pressure and upper trunk displacement and weight-bearing asymmetry between the legs. Responses were assessed in three conditions: pre-fatigue, under single-leg fatigue, and following the recovery of muscular function. Results showed (a) compensation of the non-fatigued leg through the increased magnitude of muscular activation in the first perturbation under fatigue; (b) adaptation in the non-fatigued leg over repetitive perturbations, with a progressive decrement of muscular activation over trials; and (c) maintenance of increased muscular activation of the non-fatigued leg following fatigue dissipation. These findings suggest that the central nervous system is able to modulate the descending motor drive individually for each leg's muscles apparently based on their potential contribution for the achievement of the behavioral aim of recovering stable body balance following stance perturbations.

Changes in the range of angular variation of the ankle, knee, hip and neck joints related to the awareness of an impending perturbation.

OBJECTIVES: Challenging quiet standing tasks for the ankle, knee, hip, and neck joints were used to test the effect of pre-cueing on the reaction time of articular stabilization strategies. METHOD: We assessed balance recovery in 15 subjects who were exposed to backward translations on a movable platform during two conditions: alerted, where participants gazed at a countdown light that pre-cued the onset of the platform translation; and unalerted, without onset time pre-cue. RESULTS: We compared the angular variation of the ankle, knee, hip, and neck joints between the two conditions over four window epochs (0-50 ms; 50-100 ms; 100-150 ms; 150-200 ms). When comparing the window epochs of the ankle and hip joints between conditions, a significant effect was observed in the first and second windows. In the second and third windows, a significant effect was only observed in the alerted group, thereby indicating a faster stability for alerted condition. No significant effect was observed for the knee joint, while a significant effect was observed in the neck joint during the third and fourth windows of the alerted condition. CONCLUSIONS: Pre-cueing can modify the synergies of the automatic reactive postural responses, prioritizing the stabilization of main joints such as the ankle and hip over that of the neck and knee. It was suggested that joint stabilization in the hip occurred due to the involuntary anticipation preprogrammed in the cortex by the visual pre-cue.

Stabilometric changes due to exposure to firearm noise in the Brazilian Army / Alterações estabilométricas produzidas na exposição ao ruído de arma de fogo em militares do Exército Brasileiro

Success in precision activities such as shooting depends on the subtle control of body motion. This study aimed to evaluate the influence on stabilometric signal responses for the motor task of aiming a pistol with different cognitive demands and levels of exposure to high sound pressure in Brazilian Army personnel. This cross-sectional analytical study used stabilometry to quantify the behavior of the body during motor, cognitive, and auditory tasks. Twenty-five volunteers recruited to participate in the study completed a questionnaire, underwent anthropometric evaluation and cinemetry, and scored the perceived difficulty during exposure to a sound pressure of 132 dB while using protective equipment. A significant increase in the displacement (p=0,02), anteroposterior amplitude (p=0,01), anteroposterior velocity (p=0,01), and the perceived difficulty scale (p=0,03) between Situation 1 (aiming without other cognitive action or environmental noise) and Situation 3 (shooting noise and progressive counting) was confirmed. number of shots heard). Correlation between the perceived difficulty scale and the variables of displacement (p=0,01), anteroposterior amplitude (p=0,01), area (p=0,006) and anteroposterior mean frequency (p=0,01) were observed. The accuracy of aiming events correlated with the median lateral median frequency (p=0,02). Stabilometric signals demonstrated increased total displacement, anteroposterior amplitude, and anteroposterior velocity in the presence of high sound pressure levels. These results indicate the need for future studies to investigate the underlying mechanisms of possible vestibular damage induced by noise.

O sucesso em atividades de precisão, como o tiro, depende do sutil controle das oscilações corporais.Analisar a influência nas respostas do sinal estabilométrico para a tarefa motora de pontaria com pistola, acrescidas de diferentes demandas cognitivas e exposição ao nível de pressão sonora elevado, em militares do Exército Brasileiro.Estudo de caráter transversal analítico utilizou a estabilometria para quantificar o comportamento do corpo durante três situações de pontaria distintas (variando tarefas motoras, cognitivas e auditivas). Vinte e cinco voluntários foram submetidos à pesquisa e utilizou-se: questionário, avaliação antropométrica, cinemetria, escala de dificuldade percebida e exposição ao nível de pressão sonora de 132 dB, com uso do equipamento de proteção individual. Confirmou-se um aumento significativo nas variáveis de deslocamento (p=0,02), amplitude anteroposterior (p=0,01), velocidade anteroposterior (p=0,01) e a escala de dificuldade percebida (p=0,03) entre a Situação 1 (pontaria sem outra ação cognitiva ou ruído ambiental) e a Situação 3 (pontaria com ruído de tiros e contagem progressiva do número de disparos ouvidos). Observou-se correlação entre escala de dificuldade percebida e as variáveis deslocamento (p=0,01), amplitude anteroposterior (p=0,01), área (p=0,006) e frequência média anteroposterior (p=0,01). A precisão dos eventos de pontaria se correlacionou com a frequência mediana médio lateral (p=0,02).Os sinais estabilométricos demonstraram um aumento nas oscilações do deslocamento total, amplitude ântero-posterior e a velocidade ântero-posterior, na presença de um nível de pressão sonora elevado. O resultado motiva a expansão de estudos futuros, visando averiguar os mecanismos subjacentes dos possíveis danos vestibulares induzidos por ruído.

Instantaneous interjoint rescaling and adaptation to balance perturbation under muscular fatigue.

Adaptation of automatic postural responses (APR) to balance perturbations might be thought to be impaired by muscle fatigue, given the associated proprioceptive and effector deficits. In this investigation, we aimed to evaluate the effect of muscular fatigue on APR adaptation over repetitive balance perturbations through support base backward translations. APR adaptation was evaluated in three epochs: (a) pre-fatigue; (b) post-fatigue, immediately following fatigue of the plantiflexor muscles through isometric contractions and (c) post-recovery, 30 min after the end of fatiguing activity. Results showed the following: (a) Decreasing amplitudes of joints' maximum excursion over repetitive perturbations in the three fatigue-related epochs. (b) Modulation of joints' excursion was observed in the first trial in the post-fatigue epoch. (c) In the post-fatigue epoch, we found interjoint rescaling, with greater amplitude of hip rotation associated with reduced amplitude of ankles' rotation. (d) Amplitudes of ankles' rotation were similar between the post-fatigue and post-recovery epochs. These findings lead to the conclusions that adaptation of automatic postural responses over repetitive trials was effective under focal muscular fatigue; modulation of the postural response took place in the first perturbation under fatigue, and generalization of response characteristics from post-fatigue to post-recovery suggests that feedforward processes in APRs generation are affected by the recent history of postural responses to stance perturbations.

Postural impairments in Parkinson's disease are not associated with changes in circadian rhythms changes.

Parkinson's disease (PD) is a progressive neurodegenerative disease, with a worldwide incidence of 1% in individuals >60 years of age. Its primary characteristics include postural impairments and changes in circadian rhythms. The authors investigated the association between postural impairment and changes in circadian rhythms in 24 PD subjects diagnosed with stages 1 to 3 on the Hoehn-Yard (HY) scale and regularly used dopaminergic medication for at least 1 year (experimental group - EG) and 24 healthy elderly individuals without a history of neurological impairment as the control group (CG). Static balance tests using a force plate were performed, and activity/rest rhythm, according to the relative amplitude of L5 and M10 values, was monitored for seven consecutive days using actimetry. The results indicated differences in posturographic indicators of mediolateral displacement (ML) [EG, 4.71 ± 0.85 mm; CG, 2.79 ± 0.53 mm (p < .0001)] and anteroposterior displacement of the center of pressure (COP) [EG, 5.61 ± 2.43 mm; CG, 8.23 ± 1.72 mm (< 0.0001)], ML velocity of the COP [EG, 2.39 ± 0.83 mm/s; CG, 1.40 ± 0.18 mm/s (p < .0001)], and total distance of the COP in the tandem stance condition [EG, 227.6 ± 75 mm; CG, 53.4 ± 6.1 mm (p < .0001)] between the EG and CG. There was no correlation between relative amplitude and posturographic data for the EG. Postural impairments were verified in comparing the EG and CG; however, there was no association between posturographic indicators and activity/rest rhythm.

Effects of Kinesio Taping on postural balance in patients with low back pain, a randomized controlled trial.

PURPOSE: to identify postural balance changes in subjects with low back pain after the application of Kinesio Taping, which is then compared to a no treatment control group, using baropodometric evaluation. METHODS: This randomized controlled trial was carried out on 50 individuals (both sexes) with chronic low back pain. They were then randomized into two groups: an experimental group - EG (treated with Kinesio Taping in the lumbar region) and a control group - CG (no intervention). Both groups underwent a baropodometric evaluation (mean plantar pressure, peak plantar pressure, plantar surface, mass distribution on right foot and left foot, mass distribution on forefoot and rear foot and base width) at four different moments: pre-intervention, 10 minutes, 48 hours, and 10 days after the intervention on the EG. The level of statistical significance was established at 5%. RESULTS: Significant changes were observed in the EG compared to the CG. In the EG, peak pressure reduced on both right and left foot after Kinesio Taping application; the right base width was reduced, and the mass distribution between the forefoot and the rear foot normalized towards the ideal 50% distribution. These changes happened 48 hours after the Kinesio Taping application, with effects lasting up to 10 days. CONCLUSION: The use of Kinesio Taping in the lumbar region of subjects with chronic low back pain improved postural balance. This is proved by changes in peak plantar pressure, plantar surface, and mass distribution 48 h after Kinesio Taping application, with effects lasting up to 10 days.

Investigation of the Relationship Between Electrical Stimulation Frequency and Muscle Frequency Response Under Submaximal Contractions.

Neuromuscular electrical stimulation (NMES) is a common tool that is used in clinical and laboratory experiments and can be combined with mechanomyography (MMG) for biofeedback in neuroprostheses. However, it is not clear if the electrical current applied to neuromuscular tissues influences the MMG signal in submaximal contractions. The objective of this study is to investigate whether the electrical stimulation frequency influences the mechanomyographic frequency response of the rectus femoris muscle during submaximal contractions. Thirteen male participants performed three maximal voluntary isometric contractions (MVIC) recorded in isometric conditions to determine the maximal force of knee extensors. This was followed by the application of nine modulated NMES frequencies (20, 25, 30, 35, 40, 45, 50, 75, and 100 Hz) to evoke 5% MVIC. Muscle behavior was monitored by the analysis of MMG signals, which were decomposed into frequency bands by using a Cauchy wavelet transform. For each applied electrical stimulus frequency, the mean MMG spectral/frequency response was estimated for each axis (X, Y, and Z axes) of the MMG sensor with the values of the frequency bands used as weights (weighted mean). Only with respect to the Z (perpendicular) axis of the MMG signal, the stimulus frequency of 20 Hz did not exhibit any difference with the weighted mean (P = 0.666). For the frequencies of 20 and 25 Hz, the MMG signal displayed the bands between 12 and 16 Hz in the three axes (P < 0.050). In the frequencies from 30 to 100 Hz, the muscle presented a higher concentration of the MMG signal between the 22 and 29 Hz bands for the X and Z axes, and between 16 and 34 Hz bands for the Y axis (P < 0.050 for all cases). We observed that MMG signals are not dependent on the applied NMES frequency, because their frequency contents tend to mainly remain between the 20- and 25-Hz bands. Hence, NMES does not interfere with the use of MMG in neuroprosthesis.

Influence of subcutaneous fat on mechanomyographic signals at three levels of voluntary effort

Abstract Introduction This study aims to assess the influence of different skinfold thicknesses (ST) and their relation to the attenuation of the mechanomyographic (MMG) signal at different force levels (maximal voluntary contraction – MVC, 40% of MVC and 70% of MVC) of the rectus femoris muscle. Methods Fifteen volunteers were divided in two groups: ST lower than 10mm (G<10) (8 participants) and ST higher than 35mm (G>35) (7 participants). Student t tests were employed to investigate differences between G<10 and G>35 regarding MMG analysis parameters (acceleration root mean square – aRMS, zero crossing – ZC, and median frequency – MDF), for the X, Y and Z axes, as well as for the modulus of these three axes. Results We found that thicker layers of body fat act as attenuator filters for the MMG signal [MDFMVC: X (p = 0.005), Z (p = 0.003); MDF70%MVC: X (p = 0.034); ZCMVC: Z (p = 0.037), modulus (p = 0.005); ZC70%MVC: Z (p = 0.047)]. We found significant correlation between ST values and aRMS in three levels, in the Yaxis (p = 0.591), for the group G<10. For the modulus, the aRMS value showed correlation with ST values for group G>35 in 40%MVC (R2 = 0.610), and 70%MVC (R2 = 0.592). The MDF parameter showed correlation with ST values only in the Yaxis in 70%MVC (R2 = 0.700) for G>35. Conclusions We observed MMG signal attenuation in at least one of the parameters analyzed for each level of the rectus femoris muscle force, indicating that MMG signals are significantly attenuated with increasing thickness of the subcutaneous fat layer.

Correlation between spectral and temporal mechanomyography features during functional electrical stimulation

Abstract Introduction: Signal analysis involves time and/or frequency domains, and correlations are described in the literature for voluntary contractions. However, there are few studies about those correlations using mechanomyography (MMG) response during functional electrical stimulation (FES) elicited contractions in spinal cord injured subjects. This study aimed to determine the correlation between spectral and temporal MMG features during FES application to healthy (HV) and spinal cord injured volunteers (SCIV). Methods: Twenty volunteers participated in the research divided in two groups: HV (N=10) and SCIV (N=10). The protocol consisted of four FES profiles transcutaneously applied to quadriceps femoris muscle via femoral nerve. Each application produced a sustained knee extension greater than 65º up to 2 min without adjusting FES intensity. The investigation involved the correlation between MMG signal root mean square (RMS) and mean frequency (MF). Results: HV and SCIV indicated that MMGRMS and MMGMF variations were inversely related with -0.12 ≥ r ≥ -0.82. The dispersion between MMGMF and MMGRMS reached 0.50 ≤ r2 ≤ 0.64. Conclusion The increase in MMGRMS and the decrease in MMGMF may be explained by the motor units coherence during fatigue state or by motor neuron adaptation (habituation) along FES application (without modification on parameters).

[Participation of nurses in the execution of clinical research protocol about technological innovation]. / Participação do enfermeiro na execução de protocolo de pesquisa clínica de inovação tecnológica.

OBJECTIVE: To report the nurse's experience of inclusion in interdisciplinary clinical study about technological innovation, involving people with spinal cord injury. METHOD: Descriptive experience report. The empirical support was based on notes about perspectives and practice of clinical research, with a multi-professional nursing, physical education, physiotherapy and engineering staff. RESULT: The qualification includes the elaboration of the document for the Ethics Committee, familiarization among the members of staff and with the studied topic, and also an immersion into English. The nurse's knowledge gave support to the uptake of participants and time adequacy for data collection, preparation and assistance of the participants during the intervention and after collection. Nursing theories and processes have contributed to reveal risky diagnoses and the plan of care. It was the nurse's role to monitor the risk of overlapping methodological strictness to the human aspect. The skills for the clinical research must be the object of learning, including students in multidisciplinary researches. CONCLUSION: To qualify the nurse for clinical research and to potentialize its caregiver essence, some changes are needed in the educational system, professional behavior, attitude and educational assistance.

Participation of nurses in the execution of clinical research protocol about technological innovation / Participación del enfermero en la ejecución de protocolo de investigación clínica de innovación tecnológica / Participação do enfermeiro na execução de protocolo de pesquisa clínica de inovação tecnológica

AbstractOBJECTIVETo report the nurse's experience of inclusion in interdisciplinary clinical study about technological innovation, involving people with spinal cord injury.METHODDescriptive experience report. The empirical support was based on notes about perspectives and practice of clinical research, with a multi-professional nursing, physical education, physiotherapy and engineering staff.RESULTThe qualification includes the elaboration of the document for the Ethics Committee, familiarization among the members of staff and with the studied topic, and also an immersion into English. The nurse's knowledge gave support to the uptake of participants and time adequacy for data collection, preparation and assistance of the participants during the intervention and after collection. Nursing theories and processes have contributed to reveal risky diagnoses and the plan of care. It was the nurse's role to monitor the risk of overlapping methodological strictness to the human aspect. The skills for the clinical research must be the object of learning, including students in multidisciplinary researches.CONCLUSIONTo qualify the nurse for clinical research and to potentialize its caregiver essence, some changes are needed in the educational system, professional behavior, attitude and educational assistance.

ResumenOBJETIVORelatar la experiencia de inclusión del enfermero en estudio clínico interdisciplinario de innovación tecnológica, involucrando a personas con lesión medular.MÉTODORelato de experiencia descriptivo. Las bases empíricas fueron apuntes de orientaciones y práctica de investigación clínica, con equipo multiprofesional de enfermería, educación física, fisioterapia e ingenierías.RESULTADOLa capacitación incluyó la elaboración del documento para el Comité de Ética, la familiarización con el equipo y el tema de estudio e inmersión en lengua inglesa. El conocimiento del enfermero ancló la captación de participantes y la adecuación temporal de la recolección de datos, preparación y seguimiento de los participantes durante la intervención y post recolección. Las teorías y el proceso de enfermería contribuyeron a evidenciar diagnósticos de riesgo y la planificación de cuidados.Fue papel del enfermero la vigilancia del riesgo de superposición del rigor metodológico al carácter humano. Las habilidades para la investigación clínica deberán ser objeto de aprendizaje incluyéndose a estudiantes en investigaciones multidisciplinarias.CONCLUSIÓNA fin de cualificar al enfermero para la investigación clínica y potenciar su esencia de cuidados son necesarios cambios en los sistemas de enseñanza, comportamiento profesional, actitud y soporte educativo.

ResumoOBJETIVORelatar a experiência de inclusão do enfermeiro em estudo clínico interdisciplinar de inovação tecnológica, envolvendo pessoas com lesão medular.MÉTODORelato de experiência descritivo. As bases empíricas foram anotações de orientações e prática de pesquisa clínica, com equipe multiprofissional da enfermagem, educação física, fisioterapia e engenharias.RESULTADOA capacitação incluiu a elaboração do documento para Comitê de Ética, familiarização com equipe e tema de estudo e imersão em língua inglesa. O conhecimento do enfermeiro ancorou a captação de participantes e adequação temporal da coleta de dados, preparação e acompanhamento dos participantes durante a intervenção e pós-coleta. As teorias e o processo de enfermagem contribuíram para evidenciar diagnósticos de risco e no planejamento de cuidados. Foi papel do enfermeiro a vigilância do risco de sobreposição do rigor metodológico ao caráter humano. As habilidades para a pesquisa clínica deverão ser objeto de aprendizagem incluindo estudantes em pesquisas multidisciplinares.CONCLUSÃOPara qualificar o enfermeiro para pesquisa clínica e potencializar sua essência de cuidador são necessárias mudanças nos sistemas de ensino, comportamento profissional, atitude e suporte educacional.

Advances and perspectives of mechanomyography

INTRODUCTION: The evaluation of muscular tissue condition can be accomplished with mechanomyography (MMG), a technique that registers intramuscular mechanical waves produced during a fiber's contraction and stretching that are sensed or interfaced on the skin surface. OBJECTIVE: Considering the scope of MMG measurements and recent advances involving the technique, the goal of this paper is to discuss mechanomyography updates and discuss its applications and potential future applications. METHODS: Forty-three MMG studies were published between the years of 1987 and 2013. RESULTS: MMG sensors are developed with different technologies such as condenser microphones, accelerometers, laser-based instruments, etc. Experimental protocols that are described in scientific publications typically investigated the condition of the vastus lateralis muscle and used sensors built with accelerometers, third and fourth order Butterworth filters, 5-100Hz frequency bandpass, signal analysis using Root Mean Square (RMS) (temporal), Median Frequency (MDF) and Mean Power Frequency (MPF) (spectral) features, with epochs of 1 s. CONCLUSION: Mechanomyographic responses obtained in isometric contractions differ from those observed during dynamic contractions in both passive and functional electrical stimulation evoked movements. In the near future, MMG features applied to biofeedback closed-loop systems will help people with disabilities, such as spinal cord injury or limb amputation because they may improve both neural and myoelectric prosthetic control. Muscular tissue assessment is a new application area enabled by MMG; it can be useful in evaluating the muscular tonus in anesthetic blockade or in pathologies such as myotonic dystrophy, chronic obstructive pulmonary disease, and disorders including dysphagia, myalgia and spastic hypertonia. New research becomes necessary to improve the efficiency of MMG systems and increase their application in rehabilitation, clinical and other health areas.

Iontophoresis: principles and applications / Iontoforese: princípios e aplicações

Introduction Iontophoresis is a noninvasive technique used to increase transdermal penetration of substances through the skin layer (epidermis, dermis and hypodermis) in a controlled manner. Technological advance in recent decades have provided reduced cost of equipment needed for implementation, which allowed for the expansion of this technique. Objective The aim of this paper is to present the state of the art on iontophoresis, ranging from the atomic characteristics of the ion formation to the current applications of the technique. Methods Were researched papers from databases: IOP publishing, ScienceDirect, Pubmed, Springer, IEEE Xplore, Google Scholar and books with keywords iontophoresis, ions, topical applications between 1967 and 2010. Results Were selected (number of papers and database) 1 IOP Publishing, 1 from ScienceDirect, Central, 1 from Springer, 2 from PubMed, 11 from IEEE Xplore, 35 from Google Scholar, and 15 books, totaling 66 references and websites with nationally marketed electrotherapy products. Conclusion Iontophoresis is suitable for applications such as acetic acid (calcific tendinitis and myositis ossificans), calcium chloride and magnesium sulfate (control of musculoskeletal spasms), dexamethasone (inflammation), lidocaine (inflammation of soft tissues), zinc oxide (rheumatoid arthritis). It is also used in cosmetic applications with devices attached to the skin and for eye treatment aimed at specific tissues of the eye, providing a treatment option for various eye diseases, reducing the complications secondary to traditional methods of treatment. The advantages are the significant increase in the release and control of therapeutic agents, including drugs with high molecular weight. The disadvantages of iontophoresis are the complexity of the drug release system and prolonged exposure of the skin to an electrical current. .

Introdução A iontoforese é uma técnica não invasiva utilizada para aumentar, de forma controlada, a penetração transdermal de substâncias através das camadas da pele (epiderme, derme e hipoderme). O avanço tecnológico nas últimas décadas proporcionou uma redução no custo dos equipamentos necessários à sua aplicação, o que possibilitou a expansão dessa técnica. Objetivo Apresentar o estado da arte sobre iontoforese, abrangendo desde as características atômicas da formação do íon até as atuais aplicações da técnica. Métodos Foram pesquisados artigos das bases de pesquisa: IOP publishing, ScienceDirect, Pubmed, Springer, IEEE Xplore, Google Scholar e livros com os unitermos: iontophoresis, ions, topical applications entre os anos de 1967 e 2010. Resultados Foram selecionados (número de artigos e base de pesquisa) 1 da IOP Publishing, 1 da ScienceDirect, 1 da Springer, 2 da PubMed, 11 da IEEE Xplore, 35 do Google Scholar e 15 livros, totalizando 66 referências, além de websites com produtos comerciais nacionais de eletroterapia. Conclusão A iontoforese é indicada para aplicações como de ácido acético (tendinite calcificante e miosite ossificante), cloreto de cálcio e sulfato de magnésio (controle de espasmos musculoesqueléticos), dexametasona (inflamação), lidocaína (inflamação de tecidos moles), óxido de zinco (artrite reumatóide). Também é utilizada em aplicações cosméticas com dispositivos aderidos à pele e em tratamento ocular visando tecidos específicos do olho, oferecendo uma forma de tratamento para diversas doenças oculares, diminuindo as complicações apresentadas em métodos clássicos de tratamento. As vantagens ...

Relationship between peak and mean amplitudes of the stimulating output voltage for functional control of the knee by spinal cord patients and healthy volunteers

INTRODUCTION: Functional electrical stimulation (FES) may evoke movements in people with movement impairments due to neurological lesion. The mean value of electrical current or voltage during FES depends on the stimulatory profile parameters. To investigate the relationship between peak and mean amplitudes of the stimulator output voltage while causing a knee extension angle change from 90º to 40º to choose the best and safest profile to be applied in people who have suffered a spinal cord injury. METHODS: Healthy (N = 10) volunteers and those with spinal cord injuries (N = 10) participated in this study. Each FES profile (P1, P2, P3 and P4) had 1-kHz pulses (100 µs or 200 µs on and 900 µs or 800 µs off) with burst frequencies of 50 Hz (3 ms on and 17 ms off) or 70 Hz (3 ms on and 11 ms off) and peak amplitudes set between 53-125V for healthy volunteers and 68-198 V for volunteers with spinal cord injury. RESULTS: The highest mean amplitude were obtained using a FES profile with active/total pulse period of 200 us/1000 us and burst frequency of 3ms/14ms. The best results of mean amplitude were observed using a FES profile duty cycle of 10% for pulses (100 µs/1000 µs) and 15% for bursts (3 ms/20 ms). CONCLUSION: The FES profile (100 µs - 50 Hz) seems to be the most suitable for both groups, inasmuch as it presents smaller mean amplitudes and peak amplitudes similar to other FES profiles.

Descrição do Protocolo PediaSuitTM / Description of the Pediasuit ProtocolTM

INTRODUCTION: PediaSuit ProtocolTM is an intensive therapy with a holistic approach to the treatment of individuals with neurological disorders like cerebral palsy (CP), developmental delays, traumatic brain injuries, autism and other conditions which affect a child's motor and/or cognitive functions. OBJECTIVE: The aim of the present work is to describe the PediaSuit ProtocolTM. METHODS: The authors team remained two months observing the care provided in a clinic with physical therapists trained by the PediaSuit ProtocolTM team (USA). RESULTS: The PediaSuitTM is a therapeutic protocol which uses a suit combined with intensive physical therapy and consists of up to four hours of therapy a day, five days a week, during three or four weeks. The PediaSuit ProtocolTM is customized to fit the needs of each child, with specific functional goals, and usually involves an intensive rehabilitation program. It combines the best elements of various techniques and methods, and has a sound rationale based on exercise physiology. CONCLUSION: This protocol anticipates results obtained only with long periods of conventional physical therapy.

INTRODUÇÃO: O Protocolo PediaSuitTM é uma terapia intensiva com uma abordagem holística para o tratamento de indivíduos com distúrbios neurológicos, como paralisia cerebral (PC), atrasos de desenvolvimento, lesões cerebrais traumáticas, autismo e outras condições que afetam as funções motoras e/ou cognitivas de uma criança. OBJETIVO: O objetivo do presente trabalho foi descrever o Protocolo PediaSuitTM. MÉTODOS: A equipe de autores permaneceu dois meses observando os cuidados prestados em uma clínica com fisioterapeutas treinados pela equipe PediaSuit ProtocolTM (EUA). RESULTADOS: O PediaSuitTM é um protocolo terapêutico que utiliza um traje especial combinado com a terapia física intensiva, com duração de até quatro horas por dia, cinco dias por semana, durante três ou quatro semanas. O Protocolo PediaSuitTM é personalizado para atender às necessidades de cada criança, com objetivos específicos, e, geralmente, envolve um programa intensivo de reabilitação. Ele combina os melhores elementos de várias técnicas e métodos e tem bons fundamentos com base na fisiologia do exercício. CONCLUSÃO: Esse protocolo antecipa resultados obtidos somente com longos períodos de fisioterapia tradicional.

Potencial de ação: do estímulo à adaptação neural / Action potential: from excitation to neural adaptation

INTRODUÇÃO: O potencial de ação (PA) origina-se graças a uma perturbação do estado de repouso da membrana celular, com consequente fluxo de íons, por meio da membrana e alteração da concentração iônica nos meios intra e extracelular. OBJETIVOS: Sintetizar o conhecimento científico acumulado até o presente sobre o potencial de ação neural e o seu processo de adaptação sob aplicação de um estímulo constante. MATERIAIS E MÉTODOS: Busca realizada nas bases Springer, ScienceDirect, PubMed, IEEE Xplore, Google Acadêmico, Portal de Periódicos da Capes, além de livros referentes ao assunto. O idioma de preferência selecionado foi o inglês, com as keywords: action potential; adaptation; accommodation; rheobase; chronaxy; nerve impulse. Efetuou-se a procura de artigos com uma janela de tempo de 1931 a 2010 e livros de 1791 a 2007. RESULTADOS: Dos trabalhos selecionados, foram extraídas informações a respeito dos seguintes tópicos: potencial de ação e suas fases; condução nervosa; reobase; cronaxia; acomodação; e adaptação neuronal. CONCLUSÃO: Um estímulo que crie PA, se aplicado de maneira constante, pode reduzir a frequência de despolarizações em função do tempo e, consequentemente, adaptar a célula. O tempo que a célula demora, na ausência de estímulos, para recuperar sua frequência original é definido como desadaptação.

INTRODUCTION: The action potential (AP) arises due to a disturbance of the resting state of the cell membrane with consequent flow of ions across the membrane and ion concentration changes in intra and extra cellular space. OBJECTIVES: This article aims to summarize the scientific knowledge accumulated to date on the action potential and neural adaptation in the process of applying a constant stimulus. MATERIALS AND METHODS: This is a literature review on the bases Springer, ScienceDirect, PubMed, IEEE Xplore, Google Scholar, Capes Periodicals Portal as well as books on the topic. The selected preferred language was English with the keywords: action potential; adaptation, accommodation; rheobase; chronaxy; nerve impulse. We conducted a search of articles with a wide time window from 1931 to 2010 and books from 1791 to 2007. RESULTS: In the selected studies was extracted information about the following topics: action potential and its stages; nerve conduction; rheobase; chronaxie, accommodation, and adaptation. CONCLUSION: A stimulus that creates AP, if applied consistently, can reduce the frequency of depolarization as a function of time and, consequently, to adapt the cell. The time it takes the cell in the absence of stimuli, to recover its original frequency, is defined as a disadaptation.