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1.
Medicine (Baltimore) ; 99(5): e19060, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32000454

RESUMO

The aim of the study was to evaluate pelvic floor muscle bioelectrical activity in healthy, young, and nulliparous women, and to present normative values for all phases and parameters measured with the Glazer Protocol.In this study, 96 healthy, young, nulliparous women (age 22-27 years; 168.6 ±â€Š5.1 cm; 57.1 ±â€Š11.8 kg) were tested. The bioelectrical activity of the pelvic floor muscles was collected using an endovaginal electrode with the Glazer Protocol, which included the following series of muscles contractions and relaxations: pre-baseline rest, phasic contractions, tonic contractions, isometric contractions for muscle endurance evaluation, and post-baseline rest.The following normative values of the bioelectrical signal for all phases of the Glazer Protocol were calculated: mean, minimal, and maximal values, 95% confidence interval, standard deviation, 95% standard deviation confidence interval, variance, coefficient of variation, and standard error of measurement. Average Mean Amplitude (µV) was as follows: pre-baseline rest (6.26 ±â€Š3.33 µV), phasic contractions (49.76 ±â€Š26.44 µV), tonic contractions (37.05 ±â€Š25.99 µV), endurance contraction (16.10 ±â€Š6.68 µV), and post-baseline rest (6.93 ±â€Š3.99 µV).This study was the first in which normative values for all phases of the Glazer Protocol were reported. This protocol is very often used in electromyography devices as a tool for pelvic floor muscle assessment. Due to the fact that the interpretation of the pelvic floor muscle evaluation is complex and difficult, the authors believe that the normative values proposed in this study allow for comprehensive interpretation of this test (both qualitatively and quantitatively) and provide a reference point for parameters measured in women with different pelvic floor dysfunctions.


Assuntos
Fenômenos Eletrofisiológicos , Diafragma da Pelve/fisiologia , Adulto , Eletromiografia , Feminino , Humanos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Valores de Referência
2.
World Neurosurg ; 133: 42-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31550542

RESUMO

BACKGROUND: Navigated transcranial magnetic stimulation (nTMS) is being used for different purposes in patients with brain tumors. However, the procedure requires a positive electrophysiological response. For patients with negative response in rest conditions, active motor threshold (AMT) may be used. However, sometimes it is difficult to obtain AMT measures owing to inability of the patient to sustain steady muscle contraction. Herein, we describe a simple method by using a hand dynamometer to obtain AMT measures during nTMS session. CASE DESCRIPTION: A woman aged 68 years underwent total removal of a right frontal lobe oligodendroglioma World Health Organization grade II 15 years ago. Cranial magnetic resonance imaging during follow-up revealed local recurrence. In the postoperative period, she developed left upper limb paresis. A postoperative nTMS session was performed for motor electrophysiological evaluation. However, using the standard technique for AMT measurement, the patient was unable to perform sustained muscle contraction as required. A hand dynamometer was used. It allowed sustained muscle contraction for AMT measurement. A counter force for the index finger flexion, the hand support to stabilize hand joints, and a numerical screen serving for both the examiner and the patient as a feedback parameter may explain the success obtained with this simple device. CONCLUSIONS: Although more studies are necessary to validate the method, the hand dynamometer should be considered for patients unable to sustain muscle contraction during AMT measurement.


Assuntos
Lobo Frontal/fisiopatologia , Córtex Motor/fisiopatologia , Contração Muscular/fisiologia , Dinamômetro de Força Muscular , Recidiva Local de Neoplasia/fisiopatologia , Oligodendroglioma/fisiopatologia , Estimulação Magnética Transcraniana/métodos , Idoso , Mapeamento Encefálico , Feminino , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/cirurgia , Humanos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/cirurgia , Oligodendroglioma/diagnóstico por imagem , Oligodendroglioma/cirurgia
3.
Adv Exp Med Biol ; 1131: 395-443, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31646519

RESUMO

The aim of this chapter is to discuss evidence concerning the many roles of calcium ions, Ca2+, in cell signaling pathways that control heart function. Before considering details of these signaling pathways, the control of contraction in ventricular muscle by Ca2+ transients accompanying cardiac action potentials is first summarized, together with a discussion of how myocytes from the atrial and pacemaker regions of the heart diverge from this basic scheme. Cell signaling pathways regulate the size and timing of the Ca2+ transients in the different heart regions to influence function. The simplest Ca2+ signaling elements involve enzymes that are regulated by cytosolic Ca2+. Particularly important examples to be discussed are those that are stimulated by Ca2+, including Ca2+-calmodulin-dependent kinase (CaMKII), Ca2+ stimulated adenylyl cyclases, Ca2+ stimulated phosphatase and NO synthases. Another major aspect of Ca2+ signaling in the heart concerns actions of the Ca2+ mobilizing agents, inositol trisphosphate (IP3), cADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate, (NAADP). Evidence concerning roles of these Ca2+ mobilizing agents in different regions of the heart is discussed in detail. The focus of the review will be on short term regulation of Ca2+ transients and contractile function, although it is recognized that Ca2+ regulation of gene expression has important long term functional consequences which will also be briefly discussed.


Assuntos
Sinalização do Cálcio , Coração , Animais , Cálcio/metabolismo , ADP-Ribose Cíclica , Coração/fisiologia , Humanos , Contração Muscular/fisiologia , NADP
4.
Med Probl Perform Art ; 34(4): 205-214, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31800672

RESUMO

This study compared an ergonomic alternative chair (A-chair) with a standard orchestra chair (O-chair) used by a group of 9 violin players. The features of the high-density surface EMG (HDsEMG) of the lumbar erector spinae muscles were used for the comparison. The violinists played the same pieces of music for 2 hrs without interruption on each chair in 2 different days, 1 week apart. HDsEMG was recorded for 20 s every 5 minutes using two electrode arrays of 16 × 8 electrodes each, one on each side of the spine and placed between the T11 and L4 levels. The sEMG was non-stationary and burst-like patterns were observed on 8 out of 9 violinists. The mean root mean square (RMS) and mean spectral frequency (MNF) value over the region of activity (ROA), the centroid of the ROA, the rates of change in time of the spatial mean of the RMS and MNF values, and the burst frequencies associated with the two chairs were compared. Statistically significant reductions of RMS were observed in each violinist between the O-chair and A-chair (range 11.80-78.36%). No significant changes of other spatial or spectral sEMG features were globally observed versus time or between chairs but were demonstrated by some subjects. It is concluded that the A-chair is associated with a decrease of the sEMG amplitude of the ESM without changes of the spatial and temporal patterns of muscle activation.


Assuntos
Ergonomia , Contração Muscular , Música , Eletromiografia , Humanos , Contração Muscular/fisiologia , Músculo Esquelético
5.
Int Braz J Urol ; 45(6): 1196-1203, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31808408

RESUMO

AIMS: Radical prostatectomy (RP) can result in urinary incontinence (UI) and erectile dysfunction (ED), which negatively impact quality of life (QoL). This study aimed to evaluate the effects of a perioperative pelvic floor muscle training (PFMT) program versus usual care on early recovery of urinary continence and erectile function after RP. MATERIALS AND METHODS: Of 59 eligible men, 31 were randomly allocated into 2 groups: Group 1 (Control, N=15) received usual post-RP care; and Group 2 (Physical therapy, N=16) received two pre-RP physical therapist-guided PFMT sessions, including exercises and electromyographic biofeedback, and verbal and written instructions to continue PFMT until RP, which was then resumed after urethral catheter removal. The International Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF) and the 5-item version of the International Index of Erectile Function (IIEF-5) questionnaire were used to evaluate UI and ED, respectively. RESULTS: Demographic characteristics were similar in both groups. Three months after RP, the UI rate was 72.7% and 70.0% in Groups 1 and 2, respectively (P >0.05). The severity and frequency of UI and its impact on QoL were evaluated by the ICIQ-Short Form, with scores of 6.9±6.26 in Group 1 and 7.0±5.12 in Group 2 (P >0.05). The IIEF-5 scores were similar in Groups 1 and 2 (5.73±7.43 vs. 6.70±6.68, respectively) (P >0.05). CONCLUSION: Our pre-RP protocol of two physical therapist-assisted sessions of PFMT plus instructions did not signifi cantly improve urinary continence or erectile function at 3 months after RP.


Assuntos
Disfunção Erétil/reabilitação , Exercícios de Alongamento Muscular/métodos , Diafragma da Pelve/fisiopatologia , Assistência Perioperatória/métodos , Prostatectomia/reabilitação , Incontinência Urinária/reabilitação , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Disfunção Erétil/etiologia , Disfunção Erétil/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Gradação de Tumores , Estadiamento de Neoplasias , Neurorretroalimentação , Estudos Prospectivos , Prostatectomia/efeitos adversos , Prostatectomia/métodos , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Qualidade de Vida , Inquéritos e Questionários , Resultado do Tratamento , Incontinência Urinária/etiologia , Incontinência Urinária/fisiopatologia
6.
Urologiia ; (5): 132-135, 2019 Dec.
Artigo em Russo | MEDLINE | ID: mdl-31808648

RESUMO

Three basic theories of the development of an overactive bladder that have experimental and clinical evidences have been described, including neurogenic, myogenic, and urothelial. Based on the results of the literature analysis, the authors suggested the existence of detrusor ischemic disease as a result of compressive impairment of its blood flow due to incomplete or short-term relaxation under overactivity or hydraulic compression of the vessels by excessive urine volume in case of hypoactive bladder.


Assuntos
Isquemia/fisiopatologia , Doenças da Bexiga Urinária/etiologia , Doenças da Bexiga Urinária/terapia , Bexiga Urinária/irrigação sanguínea , Hemodinâmica , Humanos , Contração Muscular/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Bexiga Urinária/fisiopatologia , Obstrução do Colo da Bexiga Urinária/complicações , Micção/fisiologia , Urodinâmica/fisiologia , Urotélio
7.
J Rehabil Med ; 51(9): 705-711, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31544949

RESUMO

OBJECTIVES: Belt electrode skeletal muscle electrical stimulation can induce muscle contraction of the whole lower body. This study examined the efficacy of belt electrode skeletal muscle electrical stimulation on reducing loss of muscle volume in critically ill patients. METHODS: Intensive care unit patients were randomly assigned to control and electrical muscle stimulation groups. In both groups, early rehabilitation was administered from day 2 of admission. In the electrical muscle stimulation group, belt electrode skeletal muscle electrical stimulation was administered. Femoral muscle volume was evaluated with computed tomography on days 1 and 10. RESULTS: Ninety-Four severely ill patients were included 47 patients were assigned to each group. Femoral muscle volumes of 16 control and 21 electrical muscle stimulation group patients were measured. For both groups, femoral muscle volume decreased significantly from day 1 to day 10 (p < 0.0001). The mean rate of muscle volume loss was 17.7% (standard deviation (SD) 10.8%) for the control group and 10.4% (SD 10.1%) for the electrical muscle stimulation group (p = 0.04). The score for stair-climbing of Barthel Index was significantly better in the electrical muscle stimulation group 3.9 (SD 4.0) than in the control group 1.5 (1.5) (p = 0.04). CONCLUSION: Belt electrode skeletal muscle electrical stimulation has the potential to inhibit muscle volume loss in critical care.


Assuntos
Estado Terminal/reabilitação , Estimulação Elétrica/métodos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Idoso , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino
8.
Int. arch. otorhinolaryngol. (Impr.) ; 23(3): 317-321, July-Sept. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1040028

RESUMO

Abstract Introduction Chewing and swallowing are physiologically interconnected functions, which share motor structures and supranuclear regions of the central nervous system (CNS), involving a sensorimotor synchrony. Objective To analyze the influence of masticatory behavior on muscular compensations in the oral phase of swallowing in smokers compared with nonsmokers. Methods A cross-sectional study comparing smokers and nonsmokers composed of 24 participants in each group. The aspects of food crunching, masticatory pattern, masticatory speed, atypical muscular contractions, and lip closure were analyzed during mastication. In swallowing, aspects of contraction of the orbicular and mental muscles, head movement and presence of deglutition, mastication, smoking, and of stomatognathic system of residues after swallowing were characterized. Results Statistically significant differences were identified between the study groups related to food grinding pattern, masticatory velocity, and mental contraction during swallowing. There was no significant association between masticatory function and compensations during swallowing. Conclusion Differences were observed in the pattern of chewing and swallowing in smokers compared with nonsmokers, but no influence of masticatory performance was observed in the presence of muscle compensations during the oral phase of swallowing.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Deglutição/fisiologia , Mastigação/fisiologia , Músculos da Mastigação/fisiologia , Sistema Estomatognático/fisiologia , Estudo Comparativo , Estudos Transversais , Fumantes , Contração Muscular/fisiologia
9.
Br J Nurs ; 28(15): 968-974, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31393761

RESUMO

Pelvic floor dysfunction is a common problem, particularly for women. A weakness in the pelvic floor muscles can lead to one or more disorders developing, such as urinary incontinence or a pelvic organ prolapse. To combat this, it is advised that the pelvic floor muscles are exercised to strengthen them and help them become more supportive. However, more than 30% of women are unable to detect their pelvic floor muscles to produce an effective contraction. The introduction of neuromuscular electrical stimulation (NMES) in pelvic healthcare poses a significant benefit in the rehabilitation of the pelvic floor muscles.


Assuntos
Terapia por Estimulação Elétrica , Força Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Diafragma da Pelve/fisiopatologia , Terapia por Exercício/métodos , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Guias de Prática Clínica como Assunto , Resultado do Tratamento , Incontinência Urinária/terapia
10.
Hum Mov Sci ; 67: 102507, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31394308

RESUMO

The aim of this study was to clarify the role of the prefrontal cortex (PFC) in physical effort regulation. We hypothesized that the PFC would be progressively involved in physical endurance through the engagement of cognitive inhibition, which would be necessary to maintain effort by inhibiting fatigue-related cues. This hypothesis was examined using a double-blind, sham-controlled, within-subjects study (N = 20) using high-definition (HD) transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (dlPFC). Participants had to maintain a knee extensor contraction at 30% of their maximal force while simultaneously performing an Eriksen flanker task to evaluate their inhibition performance during the task. Anodal stimulation of the dlPFC influenced response to the cognitive task during exercise, as seen by slower response times and better accuracy. However, it did not lead to any measureable improvement in cognitive inhibition and did not influence endurance time. There was no correlation between cognitive inhibition and the maintenance of physical effort. This result does not indicate a relationship between cognitive inhibition and endurance performance. The contribution of the PFC in physical endurance could be explained through its involvement on decisional processes.


Assuntos
Resistência Física/fisiologia , Córtex Pré-Frontal/fisiologia , Cognição/fisiologia , Tomada de Decisões/fisiologia , Método Duplo-Cego , Eletromiografia/métodos , Exercício/fisiologia , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Tempo de Reação/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto Jovem
11.
Nutrients ; 11(8)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394740

RESUMO

Exercise has beneficial effects on our health by stimulating metabolic activation of skeletal muscle contraction. Caffeine is a powerful metabolic stimulant in the skeletal muscle that has ergogenic effects, including enhanced muscle power output and endurance capacity. In the present study, we aim to characterize the metabolic signatures of contracting muscles with or without caffeine stimulation using liquid chromatography-mass spectrometry and capillary electrophoresis coupled to mass spectrometry. Isolated rat epitrochlearis muscle was incubated in the presence or absence or of 3 mM caffeine for 30 min. Electrical stimulation (ES) was used to induce tetanic contractions during the final 10 min of incubation. Principal component analysis and hierarchical clustering analysis detected 184 distinct metabolites across three experimental groups-basal, ES, and ES with caffeine (ES + C). Significance Analysis of Microarray identified a total of 50 metabolites with significant changes in expression, and 23 metabolites significantly changed between the ES and ES + C groups. Changes were observed in metabolite levels of various metabolic pathways, including the pentose phosphate, nucleotide synthesis, ß-oxidation, tricarboxylic acid cycle, and amino acid metabolism. In particular, D-ribose 5-phosphate, IMP, O-acetylcarnitine, butyrylcarnitine, L-leucine, L-valine, and L-aspartate levels were higher in the ES + C group than in the ES group. These metabolic alterations induced by caffeine suggest that caffeine accelerates contraction-induced metabolic activations, thereby contributing to muscle endurance performance and exercise benefits to our health.


Assuntos
Cafeína/farmacologia , Metabolômica , Contração Muscular/fisiologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Animais , Estimulação Elétrica , Masculino , Contração Muscular/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
12.
PLoS Comput Biol ; 15(8): e1007267, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31465437

RESUMO

This study presents a modelling framework in which information on muscle fiber direction and orientation during contraction is derived from diffusion tensor imaging (DTI) and incorporated in a computational model of the surface electromyographic (EMG) signal. The proposed model makes use of the principle of reciprocity to simultaneously calculate the electric potentials produced at the recording electrode by charges distributed along an arbitrary number of muscle fibers within the muscle, allowing for a computationally efficient evaluation of extracellular motor unit action potentials. The approach is applied to the complex architecture of the first dorsal interosseous (FDI) muscle of the hand to simulate EMG during index finger flexion and abduction. Using diffusion tensor imaging methods, the results show how muscle fiber orientation and curvature in this intrinsic hand muscle change during flexion and abduction. Incorporation of anatomically accurate muscle architecture and other hand tissue morphologies enables the model to capture variations in extracellular action potential waveform shape across the motor unit population and to predict experimentally observed differences in EMG signal features when switching from index finger abduction to flexion. The simulation results illustrate how structural and electrical properties of the tissues comprising the volume conductor, in combination with fiber direction and curvature, shape the detected action potentials. Using the model, the relative contribution of motor units of different sizes located throughout the muscle under both conditions is examined, yielding a prediction of the detection profile of the surface EMG electrode array over the muscle cross-section.


Assuntos
Imagem de Tensor de Difusão/estatística & dados numéricos , Eletromiografia/estatística & dados numéricos , Modelos Biológicos , Contração Muscular/fisiologia , Potenciais de Ação/fisiologia , Adulto , Cadáver , Biologia Computacional , Simulação por Computador , Feminino , Dedos , Análise de Elementos Finitos/estatística & dados numéricos , Humanos , Imagem Tridimensional/estatística & dados numéricos , Modelos Anatômicos , Movimento/fisiologia , Fibras Musculares Esqueléticas/fisiologia , Recrutamento Neurofisiológico/fisiologia
13.
Gait Posture ; 73: 315-322, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31419759

RESUMO

BACKGROUND: Muscle co-contraction is an accepted clinical measure to quantify the effects of aging on neuromuscular control and movement efficiency. However, evidence of increased muscle co-contraction in old compared to young adults remains inconclusive. RESEARCH QUESTION: Are there differences in lower-limb agonist/antagonist muscle co-contractions in young and old adults, and males and females, during walking and stair use? METHODS: In a retrospective study, we analyzed data from 20 healthy young and 19 healthy old adults during walking, stair ascent, and stair descent at self-selected speeds, including marker trajectories, ground reaction force, and electromyography activity. We calculated muscle co-contraction at the knee (vastus lateralis vs. biceps femoris) and ankle (tibialis anterior vs. medial gastrocnemius) using the ratio of the common area under a muscle pairs' filtered and normalized electromyography curves to the sum of the areas under each muscle in that pair. RESULTS: Old compared to young adults displayed 18%-22% greater knee muscle co-contractions during the entire cycle of stair use activities. We found greater (17%-29%) knee muscle co-contractions in old compared to young adults during the swing phase of walking and stair use. We found no difference in ankle muscle co-contractions between the two age groups during all three activities. We found no difference in muscle co-contraction between males and females at the knee and ankle joints for all three activities. SIGNIFICANCE: Based on our findings, we recommend clinical evaluation to quantify the effects of aging through muscle co-contraction to include the knee joint during dynamic activities like walking and stair use, and independent evaluation of the stance and swing phases.


Assuntos
Articulação do Tornozelo/fisiologia , Marcha/fisiologia , Articulação do Joelho/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Subida de Escada/fisiologia , Fatores Etários , Tornozelo/fisiologia , Eletromiografia , Feminino , Músculos Isquiotibiais/fisiologia , Voluntários Saudáveis , Humanos , Joelho , Masculino , Músculo Quadríceps/fisiologia , Estudos Retrospectivos , Adulto Jovem
14.
IEEE Int Conf Rehabil Robot ; 2019: 405-410, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374663

RESUMO

In the recent years important steps forward have been made in the field of signal processing on muscle signals for hand prosthetics control. At the state of the art different algorithms and techniques allow a precise estimation of hand movements. However, they mostly work exclusively on the electrode space, not seeking for any information about the currents on the contracted muscles.In this study we propose a novel simplified method to estimate the muscles currents in the forearm, along with a first experimental application on two simple movements to assess its performance. We modeled the signal propagation from muscles to electrodes using a purely resistive electrical networks and afterwards apply the graph theory to assess the muscle currents. The proposed method considerably simplify the estimation of muscle's current, decreasing the problem complexity, and therefore potentially it can be a suitable approach for future prosthetics' control.


Assuntos
Eletromiografia , Antebraço/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Processamento de Sinais Assistido por Computador , Adulto , Fenômenos Biomecânicos , Feminino , Humanos
15.
IEEE Int Conf Rehabil Robot ; 2019: 1049-1054, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374768

RESUMO

Myoelectric Computer Interfaces (MCIs) are a viable option to promote the recovery of movements following spinal cord injury (SCI), stroke, or other neurological disorders that impair motor functions. We developed and tested a MCI interface with the goal of reducing abnormal muscular activations due to compensatory strategies or undesired co-contraction after SCI. The interface mapped surface electromyographic signals (sEMG) into the movement of a cursor on a computer monitor. First, we aimed to reduce the co-activation of muscles pairs: the activation of two muscles controlled orthogonal directions of the cursor movements. Furthermore, to decrease the undesired concurrent activation of a third muscle, we modulated the visual feedback related to the position of the cursor on the screen based on the activation of this muscle. We tested the interface with six unimpaired and two SCI participants. Participants were able to decrease the activity of the targeted muscle when it was associated with the visual feedback of the cursor, but, interestingly, after training, its activity increased again. As for the SCI participants, one successfully decreased the co-activation of arm muscles, while the other successfully improved the selective activation of leg muscles. This is a first proof of concept that people with SCI can acquire, through the proposed MCI, a greater awareness of their muscular activity, reducing abnormal muscle simultaneous activations.


Assuntos
Traumatismos da Medula Espinal/reabilitação , Adolescente , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Movimento/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Interface Usuário-Computador , Adulto Jovem
16.
IEEE Int Conf Rehabil Robot ; 2019: 1061-1066, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374770

RESUMO

Natural myocontrol employs pattern recognition to allow users to control a robotic limb intuitively using their own voluntary muscular activations. The reliability of myocontrol strongly depends on the signals initially collected from the users, which must appropriately capture the variability encountered later on during operation. Since myoelectric signals can vary based on the position and orientation of the limb, it has become best practice to gather data in multiple body postures. We hereby concentrate on this acquisition protocol and investigate the relative merits of collecting data either statically or dynamically. In the static case, data for a desired hand configuration is collected while the users keep their hand still in certain positions, whereas in the dynamic case, data is collected while users move their limbs, passing through the required positions with a roughly constant velocity.Fourteen able-bodied subjects were asked to naturally control two dexterous hand prostheses mounted on splints, performing a set of complex, realistic bimanual activities of daily living. We could not find any significant difference between the protocols in terms of the total execution times, although the dynamic data acquisition was faster and less tiring. This would indicate that dynamic data acquisition should be preferred over the static one.


Assuntos
Membros Artificiais , Mãos/fisiologia , Desenho de Prótese , Atividades Cotidianas , Humanos , Contração Muscular/fisiologia , Postura/fisiologia
17.
Eur J Appl Physiol ; 119(9): 1981-1999, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31367910

RESUMO

PURPOSE: This study aimed at investigating how prior knowledge of drop heights affects proactive and reactive motor control in drop jumps (DJ). METHODS: In 22 subjects, the effect of knowledge of three different drop heights (20, 30, 40 cm) during DJs was evaluated in seven conditions: three different drop heights were either known, unknown or cheated (announced 40 cm, but actual drop height was 20 cm). Peak ground reaction force (Fmax) to body weight (BW) ratio (Fmax/BW) and electromyographic (EMG) activities of three shank and five thigh muscles were assessed 150 ms before and during ground contact (GC). Ankle, knee and hip joint kinematics were recorded in the sagittal plane. RESULTS: Leg stiffness, proactive and reactive EMG activity of the leg muscles diminished in unknown and cheat conditions for all drop heights (7-33% and 2-26%, respectively). Antagonistic co-activation increased in unknown (3-37%). At touchdown, increased flexion in knee (~ 5.3° ± 1.9°) and hip extension (~ 2° ± 0.6°) were observed in unknown, followed by an increased angular excursion in hip (~ 2.3° ± 0.2°) and knee joints (~ 5.6° ± 0.2°) during GC (p < 0.05). Correlations between changes in activation intensities, joint kinematics, leg stiffness and Fmax/BW (p < 0.05) indicate that anticipation changes the neuromechanical coupling of DJs. No dropouts were recorded. CONCLUSION: These findings underline that anticipation influences timing and adjustment of motor responses. It is argued that proactive and reactive modulations associated with diminished activation intensities in leg extensors are functionally relevant in explaining changes in leg stiffness and subsequent decline in performance.


Assuntos
Perna (Membro)/fisiologia , Movimento/fisiologia , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto , Tornozelo/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos/fisiologia , Eletromiografia/métodos , Feminino , Articulação do Quadril/fisiologia , Humanos , Joelho/fisiologia , Articulação do Joelho/fisiologia , Masculino , Coxa da Perna/fisiologia , Adulto Jovem
18.
J Sports Sci ; 37(21): 2506-2512, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31362579

RESUMO

The study assesses the test-retest reliability of movement and physiological measures during a simulated rugby match that employed activities performed in a stochastic order. Twenty male rugby players (21.4 ± 2.1 y) completed two trials of a 2 × 23 min rugby movement simulation protocol during which the order of events was performed in a stochastic order, with 7-10 days between trials. Movement characteristics, heart rate (HR), RPE, maximum voluntary contraction (MVC), voluntary activation (VA%) of the quadriceps, Stroop test and subjective task load rating (NASA-TLX) were measured. The most reliable measures of external load was relative distance (typical error [TE] and CV% = 1.5-1.6 m min-1 and 1.4-1.5%, respectively), with all other movement characteristics possessing a CV% <5%. The most reliable measure of internal load, neuromuscular function and perceptual measures were for %HRmax (TE and CV% = 1.4-1.7% and 1.4-2.1%, respectively), MVC before (TE and CV% = 10.8-14.8 N·m and 3.8-4.6%, respectively), and average RPE (TE and CV% = 0.5-0.8 AU and 3.6-5.5%, respectively). The Stroop test, NASA-TLX and blood lactate produced the least reliable measures (CV% >5%). Future studies can confidently examine changes in several perceptual, neuromuscular, physiological and movement measures related to rugby activity using stochastic movements.


Assuntos
Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Cognição/fisiologia , Futebol Americano/fisiologia , Futebol Americano/psicologia , Movimento/fisiologia , Músculo Quadríceps/fisiologia , Comportamento Competitivo/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Contração Muscular/fisiologia , Percepção/fisiologia , Esforço Físico/fisiologia , Processos Estocásticos , Teste de Stroop , Análise e Desempenho de Tarefas , Adulto Jovem
19.
Fisioterapia (Madr., Ed. impr.) ; 41(4): 192-199, jul.-ago. 2019. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-183095

RESUMO

Antecedentes y objetivos: Los músculos del abdomen, y en especial el transverso abdominal, tienen un papel fundamental en el control lumbopélvico. La maniobra de ahuecamiento abdominal es una técnica para potenciar la contracción del transverso. El objetivo del estudio es comparar mediante ecografía el cambio de grosor de la musculatura abdominal durante 2 técnicas de contracción: la contracción isométrica y la maniobra de ahuecamiento abdominal. Materiales y métodos: A una muestra de 23 voluntarios, previamente instruidos en la maniobra de ahuecamiento abdominal y la contracción isométrica, se le realizó una ecografía de la musculatura abdominal en ambos tipos de contracción y en reposo. Se midió el grosor de cada músculo y se calculó la fracción de contracción. Se analizó la existencia de diferencias significativas en la activación de la musculatura abdominal entre ambas técnicas y se evaluó la fiabilidad del análisis de imagen ecográfica. Resultados: Se observó un aumento significativo en el cambio de grosor del transverso con la maniobra de ahuecamiento (media ± DE = 2,01 ± 0,61 cm), en comparación con la contracción isométrica (media ± DE = 1,70 ± 0,65 cm). El oblicuo externo también presentó resultados mayores durante esta maniobra, mientras que el cambio de grosor del oblicuo interno fue mayor durante la contracción isométrica. El análisis de la fiabilidad interobservador fue excelente en todos los casos. Conclusiones: La maniobra de ahuecamiento abdominal produce un aumento de grosor del músculo transverso y del oblicuo externo mayor que la contracción isométrica. La ecografía es una herramienta fiable para valorar la activación de la musculatura abdominal


Introduction and objectives: The abdominal muscles, and especially the transversus abdominis, play a fundamental role in lumbopelvic control. Abdominal drawing-in maneuvre is a specific technique to transversus contraction. The objective of the study was to compare the thickness changes of the abdominal muscles with ultrasonography, during two techniques of abdominal contraction: isometric contraction and abdominal drawing-in maneuvre. Materials and methods: A sample of 23 volunteers, trained to do abdominal drawing-in maneuvre and isometric contraction were explored with ultrasonography during muscle contraction and rest. Muscle thickness and contraction fraction were calculated. Differences in the activation of the abdominal muscles between both techniques and the reliability of the ultrasound image analysis were analyzed. Results: During the abdominal drawing-in maneuvre a significant increase in thickness change of the transverse was observed (mean ± SD = 2.01 ± 0.61 cm) compared with the isometric contraction (mean ± SD=1.70 ± 0.65 cm). The external oblique also showed greater results during this maneuvre, while the change in internal oblique thickness was greater during the isometric contraction. The interobserver reliability analysis was excellent. Conclusions: The abdominal drawing-in maneuvre produces an increase in the thickness of the transverse muscle and the external oblique greater than the isometric contraction. Ultrasound is a reliable tool to assess the activation of the abdominal muscles


Assuntos
Humanos , Masculino , Feminino , Adulto , Determinação de Necessidades de Cuidados de Saúde , Contração Isométrica/fisiologia , Contração Muscular/fisiologia , Músculos Abdominais/diagnóstico por imagem , Músculos Abdominais/fisiologia , Voluntários Saudáveis , Estudos Transversais , Estudantes de Ciências da Saúde/estatística & dados numéricos , Ultrassonografia/instrumentação
20.
Gait Posture ; 73: 173-179, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31344606

RESUMO

BACKGROUND: Groin pain is one of the common problems in multidirectional sports. It seems that abnormal muscular activity and improper movement strategy led to prolongation and high rate of this injury. Therefore, the aim of this study was to Comparing the Average amplitude of Electromyography (AEMG), co-contraction ratio (CCR) of selected thigh and thoracic muscle during turning in individuals with chronic groin pain and healthy individuals. METHODS: Surface electromyography was collected from the internal oblique/transversus abdominis (IO/TrA), multifidus (MF), adductor Longus (AL) and gluteus Medius (GM) for AEMG and CCR analyzed in 16-males with LSGP and 16-controls in four motion phases during 11 cycles of gait coupled with turning. RESULTS: Results revealed that in the AEMG apart from the third phase in the muscle of the IO/ Tr. A muscle and in the second phase in the MF muscle in the trunk and in the third phase in the muscle of the AL and the fourth phase in the GM foot Left There was a significant difference in other phases. There was a significant difference in the CCR, except in the second phase of the trunk and the fourth phase of the left foot in the rest of the phases. CONCLUSIONS: It seems that in athletes with LSGP, have selective muscular activation and CCR have during turning, that may be resulting in compensatory strategies and movement control defects, which may be a useful tool to predict LSGP occurrence in players with a history of groin pain.


Assuntos
Virilha/fisiopatologia , Contração Muscular/fisiologia , Dor/fisiopatologia , Futebol/fisiologia , Adulto , Atletas , Estudos de Casos e Controles , Estudos Transversais , Eletromiografia , Humanos , Masculino , Músculo Esquelético/fisiologia
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