Muscle EMG Research Articles

Nasal High Flow to Modulate Dyspnea in Orally Intubated Patients.

High flow therapy reduces dyspnea in acute respiratory failure but the underlying mechanisms are not fully elucidated. To compare dyspnea, airway occlusion pressure (P0.1) and inspiratory work with and without nasal high flow (NHF, FiO2 21%, temperature 31°C) in intubated patients under pressure support ventilation and during a spontaneous breathing trial (SBT). Dyspnea (numerical rating scale, NRS and Mechanical Ventilation - Respiratory Distress Observational Scale, MV-RDOS), P0.1, esophageal pressure, respiratory muscles EMG, arterial blood gas were compared in intubated patients on pressure support ventilation presenting a dyspnea-NRS > 3 during two sequences: 1) pressure support ventilation with NHF at 0 L/min followed by 30, 50 and 60 L/min (the last three were randomized) and 2) a SBT with NHF at 0 and 50 L/min (randomized). Twenty patients were included. During pressure support ventilation, as compared to dyspnea-NRS that was 5 (4 - 6) at NHF 0 L/min, dyspnea-NRS was 3 (2 - 6) and 3 (2 - 5) at NHF 30L/min and NHF 50L/min, respectively (p<0.05). However, there was no change in MV-RDOS, P0.1, esophageal pressure, respiratory muscles EMG and gas exchange. During the SBT, at NHF 50 L/min, dyspnea-NRS and P0.1 were lower than during the SBT at NHF 0 L/min (p<0.01 and p=0.04 respectively) whereas MV-RDOS, esophageal pressure, respiratory muscles EMG did not change as compared to SBT with NHF 0 L/min. In orally intubated patients, nasal high flow was associated with lower dyspnea and lower respiratory drive without affecting the inspiratory work.

Progress in research and application of respiratory surface electromyography in respiratory and critical care medicine

Continuous monitoring of respiratory drive plays an important role in guiding mechanical ventilation and assessing changes in disease, but respiratory drive cannot be measured directly. Respiratory and critical care practitioners often monitor respiratory effort to reflect respiratory drive, such as esophageal pressure and esophageal diaphragm electrical activity, but these methods are limited by their invasive nature, high technical requirements, and high cost. Esophageal diaphragmatic electromyography only monitors the activity level of the diaphragm and ignores other respiratory muscles, especially in patients who breathe forcefully and cannot truly reflect the patient's inspiratory effort. As a result, the monitoring of esophageal pressure and esophageal diaphragmatic electromyography activity are limited in clinical application. Surface electromyography (sEMG) of respiratory muscles is a non-invasive method for monitoring respiratory electromyographic activity that can be used to monitor the activity levels of all respiratory muscles and evaluate their functional status. This paper summarized the progress of sEMG in evaluating dyspnea, predicting acute exacerbations of chronic obstructive pulmonary disease, diagnosing bronchial asthma, guiding mechanical ventilation, and formulating respiratory muscle training programs to provide a new method of assessing respiratory effort.

Estimating descending activation patterns from EMG in fast and slow movements using a model of the stretch reflex.

Due to spinal reflex loops, descending activation from the brain is not the only source of muscle activation that ultimately generates movement. This study directly estimates descending activation patterns from measured patterns of muscle activation (EMG) during human arm movements. A simple model of the spinal stretch reflex is calibrated in a postural unloading task and then used to estimate descending activation patterns from muscle EMG patterns and kinematics during voluntary arm motion performed at different speeds. We observed three key features of the estimated descending activation patterns: (1) Within about the first 15% of movement duration, descending and muscle activations are temporally aligned. Thereafter, they diverge and develop qualitatively different temporal profiles. (2) The time course of descending activation is monotonic for slow movements, non-monotonic for fast movements. (3) Varying model parameters like the spinal reflex gain or the level of co-contraction does not qualitatively change the temporal pattern of estimated descending activation. Our findings highlight the substantial contribution of spinal reflex loops to movement generation, while at the same time providing evidence that the brain must generate qualitatively different descending activation patterns for movements that vary in their mechanical dynamics.

Clinical experience of the carboxytherapy method in the treatment of patients with temporomandibular joint pain dysfunction syndrome (К07.60)

Objective. Improving the effectiveness of treatment of patients with TMJ PDS myogenic origin. Material and methods. According to the purpose of the study, a group of 10 patients (8 women and 2 men aged 14 to 60 years) was formed with the coincidence of a triad of signs: pain during movements of the lower jaw, a feeling of heaviness and tension in the chewing and facial muscles, restriction of mouth opening. A set of diagnostic measures has been implemented in the following scope: clinical and radiological examination methods, TMJ MRI, ultrasound and surface EMG of the chewing muscles, digital axiography. In the treatment of patients in the study group, the method of invasive carboxytherapy was used, based on dosed injections of CO2 in the projection of trigger points of the masticatory muscles. The research examines the therapeutic value of using of CO2 in the protocol of functional rehabilitation of patients with TMJ diseases of myogenic origin. Results. The analysis of the effectiveness of treatment of patients in the study group was carried out to assess the dynamics of key parameters: the severity of the pain syndrome according to VAS, the magnitude of the IMPACT index values and the magnitude of mouth opening. The severity of pain in patients in the study group, according to average values, decreased by 86% from the initial values, an increase in the amplitude of mouth opening by 28.5%, a decrease in the IMPACT index values by 42.5% from the initial values of hypertonicity of the masticatory muscles, an increase in blood flow speed of superficial temporal artery at 52.5%. Conclusion. The results of the clinical application of the carboxytherapy method in the treatment of patients with TMJ PDS allow us to recommend this method for implementation in the rehabilitation protocols of patients with TMJ PDS of myogenic origin, trismus and hypertonus of the masticatory muscles. Carboxytherapy as a method of etiopathogenetic rehabilitation contributes to the early relief of pain syndrome, normalization of the bioelectric activity of the chewing muscles and restoration the physiological kinematics of the lower jaw’s movements.

MCLAS adaptively rescues disease-specific sleep and wake phenotypes in neurodegeneration

Sleep alterations are hallmarks of prodromal Alzheimer's (AD) and Parkinson's disease (PD), with fundamental neuropathological processes of both diseases showing susceptibility of change upon deep sleep modulation. However, promising pharmacological deep sleep enhancement results are hindered by specificity and scalability issues, thus advocating for noninvasive slow-wave activity (SWA) boosting methods to investigate the links between deep sleep and neurodegeneration. Accordingly, we have recently introduced mouse closed-loop auditory stimulation (mCLAS), which is able to successfully boost SWA during deep sleep in neurodegeneration models. Here, we aim at further exploring mCLAS’ acute effect onto disease-specific sleep and wake alterations in AD (Tg2576) and PD (M83) mice. We found that mCLAS adaptively rescues pathological sleep and wake traits depending on the disease-specific impairments observed at baseline in each model. Notably, in AD mice mCLAS significantly increases NREM long/short bout ratio, decreases vigilance state distances by decreasing transition velocities and increases the percentage of cumulative time spent in NREM sleep in the last 3h of the dark period. Contrastingly, in PD mice mCLAS significantly decreases NREM sleep consolidation, by potentiating faster and more frequent transitions between vigilance states, decreases average EMG muscle tone during REM sleep and increases alpha power in WAKE and NREM sleep. Overall, our results indicate that mCLAS selectively prompts an acute alleviation of neurodegeneration-associated sleep and wake phenotypes, by either potentiating sleep consolidation and vigilance state stability in AD or by rescuing bradysomnia and decreasing cortical hyperexcitability in PD. Further experiments assessing the electrophysiological, neuropathological and behavioural long-term effects of mCLAS in neurodegeneration may majorly impact the clinical establishment of sleep-based therapies.

Supraspinal contributions to defective antagonistic inhibition and freezing of gait in Parkinson's disease.

The neuromuscular circuit mechanisms of freezing of gait in Parkinson's disease have received little study. Technological progress enables researchers chronically to sense local field potential activity of the basal ganglia in patients while walking. To study subthalamic activity and the circuit processes of supraspinal contributions to spinal motor integration, we recorded local field potentials, surface EMG of antagonistic leg muscles and gait kinematics in patients while walking and freezing. To evaluate the specificity of our findings, we controlled our findings to internally generated volitional stops. We found specific activation-deactivation abnormalities of oscillatory activity of the subthalamic nucleus both before and during a freeze. Furthermore, we were able to show with synchronization analyses that subthalamo-spinal circuits entrain the spinal motor neurons to a defective timing and activation pattern. The main neuromuscular correlates when turning into freezing were as follows: (i) disturbed reciprocity between antagonistic muscles; (ii) increased co-contraction of the antagonists; (iii) defective activation and time pattern of the gastrocnemius muscle; and (iv) increased subthalamo-muscular coherence with the gastrocnemius muscles before the freeze. Beyond the pathophysiological insights into the supraspinal mechanisms contributing to freezing of gait, our findings have potential to inform the conceptualization of future neurorestorative therapies.

Train-of-four ratio, counts and post tetanic counts with the Tetragraph electromyograph in comparison to mechanomyography.

Automated EMG devices to detect compound muscle action potentials from the adductor pollicis muscle in response to ulnar nerve stimulation, regardless of hand and thumb position, may serve as a better reference ("gold standard") for clinical assessment of neuromuscular function than traditional mechanomyography (MMG) systems that need custom design and validation in lab settings. This evaluation compared the TetraGraph EMG system against a validated MMG device to investigate the accuracy and repeatability of this quantitative EMG monitor for detecting onset, offset and deep neuromuscular block. Simultaneous muscle action potential recordings from the EMG neuromuscular monitor and muscle contractions from an in-house developed MMG monitor in response to ulnar nerve stimulation were obtained from patients having elective surgery requiring neuromuscular block. Train-of-four (TOF) ratios, TOF counts, and post-tetanic counts (PTCs) were recorded simultaneously from the same hand muscle and compared. In total, 685 pairs of simultaneous TOF ratios were evaluated. The mean difference (bias) of TOF ratios between devices was small (-2.1%). TOF counts from 285 data pairs were within a count of 2 or less 96% of the time. During deep block, PTC comparisons from 215 data pairs were within a count of 2 or less 95% of the time. These findings, along with prior EMG device evaluations, indicate that real-time EMG neuromuscular monitoring technology to detect muscle action potentials from the adductor pollicis in the clinical setting is closely aligned with the force of thumb contraction determined from MMG. The accuracy of quantitative EMG technology of the TetraGraph EMG system lends strong support for this monitor, along with other similarly validated EMG monitors, to become a clinical standard for all phases (onset, depth and reversal) of neuromuscular block in clinical practice.

The Effect of 8 Weeks of Dynamic Neuromuscular Stabilization Training on Pain, Electromyography Activity of Lumbar Muscles, and Quality of Life in People with Chronic Low Back Pain

Objectives: To evaluate the effects of an 8-week DNS training program on pain, EMG activity, and quality of life in individuals with CLBP. Design: Semi-experimental study. Participants: Thirty male participants with non-specific CLBP, divided into DNS (n=15) and control (n=15) groups. Main Outcome Measures: Pain levels (Quebec Back Pain Disability Scale), lumbar muscle EMG activity (MegaWin EMG device), and quality of life (SF-36 questionnaire). Results: The DNS group showed significant pain reduction (P=0.00), increased EMG activity in rectus abdominis (P=0.000), erector spinae (P=0.002), and gluteus maximus (P=0.002), and improved quality of life (P=0.02). Conclusions: DNS exercises significantly reduce pain, enhance muscle activity, and improve quality of life in CLBP patients

EFFECTS OF SPINAL TRANSECTION AND LOCOMOTOR SPEED ON MUSCLE SYNERGIES OF THE CAT HINDLIMB.

It was suggested that during locomotion, the nervous system controls movement by activating groups of muscles, or muscle synergies. Analysis of muscle synergies can reveal the organization of spinal locomotor networks and how it depends on the state of the nervous system, such as before and after spinal cord injury, and on different locomotor conditions, including a change in speed. The goal of this study was to investigate the effects of spinal transection and locomotor speed on hindlimb muscle synergies and their time-dependent activity patterns in adult cats. EMG activities of 15 hindlimb muscles were recorded in 9 adult cats of either sex during tied-belt treadmill locomotion at speeds of 0.4, 0.7, and 1.0 m/s before and after recovery from a low thoracic spinal transection. We determined EMG burst groups using cluster analysis of EMG burst onset and offset times and muscle synergies using non-negative matrix factorization. We found five major EMG burst groups and five muscle synergies in each of six experimental conditions (2 states × 3 speeds). In each case, the synergies accounted for at least 90% of muscle EMG variance. Both spinal transection and locomotion speed modified subgroups of EMG burst groups and the composition and activation patterns of selected synergies. However, these changes did not modify the general organization of muscle synergies. Based on the obtained results, we propose an organization for a pattern formation network of a two-level central pattern generator that can be tested in neuromechanical simulations of spinal circuits controlling cat locomotion.

Human Muscle sEMG Signal and Gesture Recognition Technology Based on Multi-Stream Feature Fusion Network

Surface electromyography signals have significant value in gesture recognition due to their ability to reflect muscle activity in real time. However, existing gesture recognition technologies have not fully utilized surface electromyography signals, resulting in unsatisfactory recognition results. To this end, firstly, a Butterworth filter was adopted to remove high-frequency noise from the signal. A combined method of moving translation threshold was introduced to extract effective signals. Then, a gesture recognition model based on multi-stream feature fusion network was constructed. Feature extraction and fusion were carried out through multiple parallel feature extraction paths, combined with convolutional neural networks and residual attention mechanisms. Compared to popular methods of the same type, this new recognition method had the highest recognition accuracy of 92.1% and the lowest recognition error of 5%. Its recognition time for a single-gesture image was as short as 4s, with a maximum Kappa coefficient of 0.92. Therefore, this method combining multi-stream feature fusion networks can effectively improve the recognition accuracy and robustness of gestures and has high practical value.

Tongue brushing enhances the myoelectric activity of the suprahyoid muscles in older adults: a six-week randomized controlled trial

Tongue brushing improves respiratory function in older adults. Considering connection between the respiratory-related and suprahyoid muscles, this study aimed to investigate whether tongue-brushing interventions can improve myoelectric activity during respiration. A six-week randomized controlled trial was conducted in Kitakyushu, Japan, with 50 participants aged ≥ 65 years. The participants were allocated to the intervention (tongue brushing with routine oral hygiene) or control (routine oral hygiene alone) groups. Surface electromyography (sEMG) was used to assess the myoelectric activity of the suprahyoid muscles during inhalation, exhalation, and forced vital capacity (FVC). A survey was conducted at baseline and the end of the follow-up period. Thirty-six participants were recruited for the analysis. The root mean squares (RMS) of sEMG during exhalation increased significantly at the end of the follow-up period compared with that at baseline in the intervention group [48.7 (18.0–177.5) vs. 64.9 (21.6–163.0), p = 0.001], but not in the control group. The generalized linear model revealed that the ratio of change in FVC was correlated with the change in the RMS of sEMG of the suprahyoid muscles during exhalation after adjusting for potential confounders. Tongue brushing enhances the myoelectric activity of the suprahyoid muscle.

A randomized controlled trial of low-frequency repeated transcranial magnetic stimulation in patients with poststroke neurogenic bladder

Urinary incontinence is a common complication in stroke survivors for whom new interventions are needed. This study investigated the therapeutic effect of low-frequency (LF) repeated transcranial magnetic stimulation (rTMS) on the contralesional primary motor cortex (M1) in patients with poststroke urinary incontinence (PSI). A total of 100 patients were randomly assigned to the rTMS group or sham-rTMS group on basis of the intervention they received. Both groups underwent five treatment sessions per week for 4 weeks. Data from the urodynamic examination were used as the primary outcome. The secondary outcome measures were questionnaires and pelvic floor surface electromyography. After 4 weeks of intervention, the maximum cystometric capacity (MCC), maximum detrusor pressure (Pdet.max), residual urine output, overactive bladder score (OABSS) (including frequency, urgency, and urgency urinary incontinence), and the ICIQ-UI SF improved significantly in the rTMS group compared with those in the sham-rTMS group (P < 0.05). However, no changes in pelvic floor muscle EMG were detected in patients with PSI (both P > 0.05). Our data confirmed that 4 weeks of LF-rTMS stimulation on the contralateral M1 positively affects poststroke urinary incontinence in several aspects, such as frequency, urgency urinary incontinence, MCC, end-filling Pdet, OABSS, and ICIQ-UI SF scores.

Exploring botulinum toxin’s impact on masseter hypertrophy: a randomized, triple-blinded clinical trial

The present study aimed to assess the effectiveness and functional adverse effects of a single and multiple injections of botulinum toxin A (BoNT-A) for masseter hypertrophy (MH). Twenty-six women complaining about lower third facial enlargement due to MH, received 75 U of BoNT-A (abobotulinum toxin) in each masseter muscles. After 3 months, patients were randomly assigned to receive a second treatment session of Saline Solution: (G1; n = 11) or BoNT-A: (G2; n = 12). Muscle thickness (ultrasound), electrical activity (electromyography; EMG), masticatory performance, and subjective perception of MH were evaluated. Follow-up was performed at 1, 3 and 6 months. Muscle thickness, EMG activity, and masticatory performance were analyzed using ANOVA two-way and Sidak test as post-hoc. Masticatory performance was analyzed by the Friedman’s test and Mann–Whitney test. Regarding inter-groups comparisons, there was a significant decrease in the left masseter muscle thickness in the G2 group at the 6 month follow-up (p < 0.02). For EMG, significant differences were evident at the 6 month assessment, with higher masseter activity for G1 (p < 0.05). For masticatory performance, no significant differences were observed throughout the study (p > 0.05) and a higher improvement in subjective perception of MH was observed in the 1 month follow-up for G2 (p < 0.05). In conclusion, BoNT-A is effective for MH, however multiple injections cause functional adverse effects in masseter muscle.

Exoskeleton rehabilitation robot training for balance and lower limb function in sub-acute stroke patients: a pilot, randomized controlled trial

PurposeThis pilot study aimed to investigate the effects of REX exoskeleton rehabilitation robot training on the balance and lower limb function in patients with sub-acute stroke.MethodsThis was a pilot, single-blind, randomized controlled trial. Twenty-four patients with sub-acute stroke (with the course of disease ranging from 3 weeks to 3 months) were randomized into two groups, including a robot group and a control group. Patients in control group received upright bed rehabilitation (n = 12) and those in robot group received exoskeleton rehabilitation robot training (n = 12). The frequency of training in both groups was once a day (60 min each) for 5 days a week for a total of 4 weeks. Besides, the two groups were evaluated before, 2 weeks after and 4 weeks after the intervention, respectively. The primary assessment index was the Berg Balance Scale (BBS), whereas the secondary assessment indexes included the Fugl-Meyer Lower Extremity Motor Function Scale (FMA-LE), the Posture Assessment Scale for Stroke Patients (PASS), the Activities of Daily Living Scale (Modified Barthel Index, MBI), the Tecnobody Balance Tester, and lower extremity muscle surface electromyography (sEMG).ResultsThe robot group showed significant improvements (P < 0.05) in the primary efficacy index BBS, as well as the secondary efficacy indexes PASS, FMA-LE, MBI, Tecnobody Balance Tester, and sEMG of the lower limb muscles. Besides, there were a significant differences in BBS, PASS, static eye-opening area or dynamic stability limit evaluation indexes between the robotic and control groups (P < 0.05).ConclusionsThis is the first study to investigate the effectiveness of the REX exoskeleton rehabilitation robot in the rehabilitation of patients with stroke. According to our results, the REX exoskeleton rehabilitation robot demonstrated superior potential efficacy in promoting the early recovery of balance and motor functions in patients with sub-acute stroke. Future large-scale randomized controlled studies and follow-up assessments are needed to validate the current findings.Clinical trials registrationURL: https://www.chictr.org.cn/index.html.Unique identifier: ChiCTR2300068398.

Advanced subject-specific neck musculoskeletal modeling unveils sex differences in muscle moment arm and cervical spine loading

Neck pain and injuries are growing healthcare burdens with women having a higher incidence rate and poorer treatment outcomes than males. A better understanding of sex differences in neck biomechanics, foundational for more targeted, effective prevention or treatment strategies, calls for more advanced subject-specific musculoskeletal modeling. Current neck musculoskeletal models are based on generic anatomy, lack subject specificity beyond anthropometric scaling, and are unable to accurately reproduce neck strengths exhibited in vivo without arbitrary muscle force scaling factors or residual torque actuators. In this work, subject-specific neck musculoskeletal models of 23 individuals (11 male, 12 female) were constructed by integrating multi-modality imaging and biomechanical measurements. Each model simulated maximal voluntary neck static exertions in three postures: neck flexion in a neutral posture, flexion in a 40° extended posture, and extension in a 40° flexed posture. Quantitative model validation showed close agreement between model-predicted muscle activation and EMG measurement. The models unveiled that (1) males have greater moment arms in one flexor muscle group and five extensor muscle groups, (2) females exhibited higher cervical spinal compression per unit exertion force in the flexed posture, and (3) the variability of compression force was much greater in females in all three exertions but most notably in the extension with a flexed “dropped head” position. These insights illuminated a plausible pathway from sex differences in neck biomechanics to sex disparities in the risk and prevalence of neck pain.

Sustained Muscle EMG Activity to Contractile Failure During Incremental Exercise and Intense Constant Load Cycling: No Evidence of a Central Governor

Since 1997, debate has continued over the presence of a central governor that constrains neuromuscular activity during severe, intense exercise. This study aimed to challenge the central governor model (CGM) through acquiring surface electromyography (sEMG) data from the vastus lateralis (VL) and gluteus maximus (Gmax) muscles of 14 healthy participants during 4 different bouts of constant load, non-steady state cycling exercise (110, 125, 140, 160 %watts at the ventilation threshold), and 1 incremental bout to volitional exhaustion. sEMG activity was processed to isolate and capture each contraction of the VL and Gmax during all bouts of exercise. sEMG data was then graphed to profile sEMG root mean square (rms) activity over time with linear curve fitting used to quantify this relationship for data preceding (segment 1) and during the final 30s of each test (segment 2). Two-way repeated measures ANOVA was used to test for differences between the slopes of the two linear segments of the sEMG rms response of the VL for each bout. Results during the VO2max trial revealed a significant main effect for SEGMENT where segment 2 was significantly greater than segment 1 (F=6.741, p=0.023). During the critical power trails there were significant differences in sEMG rms for each of INTENSITY (F=9.349, p&lt;0.001), SEGMENT (F=5.443, p=0.036), and the interaction effect (F=2.837, p=0.005). Muscle sEMG rms data revealed sustained increases in muscle activity in all bouts of intense exercise to volitional exhaustion in both the VL and Gmax, which is inconsistent with the predictions made from the CGM.

Is sleep bruxism in obstructive sleep apnea only an oral health related problem?

BackgroundThe etiology of sleep bruxism in obstructive sleep apnea (OSA) patients is not yet fully clarified. This prospective clinical study aimed to investigate the connection between probable sleep bruxism, electromyographic muscle tone, and respiratory sleep patterns recorded during polysomnography.Methods106 patients with OSA (74 males, 31 females, mean age: 56.1 ± 11.4 years) were divided into two groups (sleep bruxism: SB; no sleep bruxism: NSB). Probable SB were based on the AASM criteria: self-report of clenching/grinding, orofacial symptoms upon awakening, abnormal tooth wear and hypertrophy of the masseter muscle. Both groups underwent clinical examination for painful muscle symptoms aligned with Temporomandibular Disorders Diagnostic Criteria (DC/TMD), such as myalgia, myofascial pain, and headache attributed to temporomandibular disorder. Additionally, non-complaint positive muscle palpation and orofacial-related limitations (Jaw Functional Limited Scale-20: JFLS-20) were assessed. A one-night polysomnography with electromyographic masseter muscle tone (EMG) measurement was performed. Descriptive data, inter-group comparisons and multivariate logistic regression were calculated.ResultsOSA patients had a 37.1% prevalence of SB. EMG muscle tone (N1-N3, REM; P = 0.001) and the number of hypopneas (P = 0.042) were significantly higher in the sleep bruxism group. While measures like apnea–hypopnea-index (AHI), respiratory-disturbance-index (RDI), apnea index (AI), hypopnea-index (HI), number of arousals, and heart rate (1/min) were elevated in sleep bruxers, the differences were not statistically significant. There was no difference in sleep efficiency (SE; P = 0.403). Non-complaint masseter muscle palpation (61.5%; P = 0.015) and myalgia (41%; P = 0.010) were significant higher in SB patients. Multivariate logistic regression showed a significant contribution of EMG muscle tone and JFLS-20 to bruxism risk.ConclusionIncreased EMG muscle tone and orofacial limitations can predict sleep bruxism in OSA patients. Besides, SB patients suffer more from sleep disorder breathing. Thus, sleep bruxism seems to be not only an oral health related problem in obstructive apnea. Consequently, interdisciplinary interventions are crucial for effectively treating these patients.Trial registrationThe study was approved by the Ethics Committee of Philipps-University Marburg (reg. no. 13/22—2022) and registered at the “German Clinical Trial Register, DRKS” (DRKS0002959).

Acute effects of blood flow restriction on EMG activity of arm muscles during karate tsuki strike in young men

BackgroundThe positive effect of Blood Flow Restriction (BFR) on muscular performance have been documented in previous researches. However, its effect on agonist-antagonist cocontraction during fist movement has not been considered from a biomechanical perspective. The purpose of this research was to investigate the acute effect of BFR on EMG activity of arm muscles during karate tsuki strike in young men. Methods20 professional young, male karatekas voluntarily participated in this research. Biceps and triceps muscular activity and their cocontraction in the right arm (with BFR) and the left arm (control) were captured and compared using an EMG device during tsuki strike until exhaustion. ResultsThe results of independent t-test showed that biceps and triceps EMG activity in the BFR arm were significantly higher than the control arm (24.45% and 27.78% for biceps and triceps, respectively). Moreover, muscular cocontraction in BFR arm was significantly less than control arm (32.05%). ConclusionThe results indicate that acute arm BFR can increase arm muscle EMG activity during tsuki strike until exhaustion, which indirectly it is a sign for activation of type II motor units. However, BFR decreased agonist-antagonist cocontraction, which may increase the risk for injury during elbow extension in throw fist.

Relationship between abnormal pelvic floor electromyography and obstetric factors in postpartum women: a cross-sectional study

ObjectiveTo evaluate the surface electromyography (sEMG) of pelvic floor muscles (PFMs), compare between vaginal birth and cesarean section and correlate with maternity and obstetrics characteristics in primiparous 6–8 weeks postpartum.MethodsPFMs surface electromyography screening data of primiparous postpartum women in our hospital at 6–8 weeks postpartum from 2018 to 2021 were selected and analyzed. The study collected data on delivery activities of 543 postpartum women totally.ResultsIn general, the abnormal incidence of pelvic floor electromyography in postpartum women mainly occurred in slow muscle (type I fiber) stage and endurance testing stage. Compared to vaginal birth postpartum women, the incidence of abnormal pelvic floor electromyography in cesarean section postpartum women is lower. There were statistical differences in measurement values of pelvic floor electromyography in several different stages between cesarean section and vaginal birth (P < 0.005). Regarding the influence on pelvic floor electromyography, there were more influencing factors on vaginal birth postpartum women including age, height, weight, weight gain during pregnancy, gestational week, and first and second stage of labor than on cesarean section postpartum women whose influencing factors included age, weight gain during pregnancy, and newborn weight.ConclusionEffects on surface electromyography (sEMG) of pelvic floor muscles (PFMs) at 6–8 weeks postpartum differed based on the different modes of delivery. The high-risk obstetric factors closely related to abnormal surface electromyography (sEMG) of pelvic floor muscles (PFMs) were maternal age, height, weight, and second stage of labor.

ELECTROMYOGRAPHY AS A METHOD FOR ASSESSING THE EFFECTIVENESS OF ORTHOPEDIC TREATMENT OF PATHOLOGICAL ABRASION OF HARD TISSUES OF TEETH

The combination of pathological wear of the teeth with defects of the dental rows causes significant changes in the maxillofacial complex, which leads to substantial morphofunctional disorders and creates difficulties in the orthopedic rehabilitation of such patients.&#x0D; The combination of pathological tooth wear and defects of the dental rows causes significant changes in the maxillofacial complex, which leads to substantial morphofunctional disorders and creates difficulties in the orthopedic rehabilitation of such patients.&#x0D; Thirty four persons aged from 35 to 60 years with a generalized form of pathological wear of grades I-II, in combination with defects of dentition of classes I, II and III according to Kennedy, were treated. The examination has included the data of the anamnesis, general clinical examination, measuring interalveolar height, study of diagnostic models, X-ray examination, and EMG of the masticatory muscles.&#x0D; The results. The EMG data of the research groups before treatment showed a different degree of the rhythm of chewing movements, a clear alternation of the phases of activity and rest, uneven inclusion of motor units in the contraction process compared to healthy patients, the habitual side of chewing was determined, as a result of which an extension of chewing time, a decrease in its rhythm and chewing efficiency.&#x0D; Thirty days after the appropriate treatment, the electromyographic study showed morphological and functional changes in the maxillofacial apparatus of the patients of the experimental groups, which were reflected in the quantitative indicators of the EMG of the masticatory muscles. In the I group, the EMG parameters significantly approached those in the control group, and in the II group, a tendency to approach the norm was determined.&#x0D; Appropriate orthopedic treatment of pathological attrition, complicated by existing dentition defects, various structures contributed to the emergence of new myotatic reflexes, the creation of a new chewing stereotype.&#x0D; A positive change in EMG indicators, especially the "K" coefficient, and their approach to the indicators of the control group indicates the appropriate choice of the prosthetic method, which will contribute to the process of adaptation to the orthopedic structure and improve the psycho-somatic condition of patients in general.&#x0D; Conclusions. Analyzing the variance in biopotentials of the masticatory muscles enables the evaluation of both the extent and the characteristics of existing disorders in patients with pathological attrition.&#x0D; The positive dynamics of electromyography indicators in the treatment of patients with a generalized form of pathological wear, complicated by defects of the dental rows, indicates the quality of the treatment, the feasibility of choosing an orthopedic structure, and the smoothness of the process of adaptation to it.&#x0D; The future research involves continued monitoring of long-term treatment outcomes, including the potential for determining the duration required for complete adaptation to the orthopedic prosthesis.