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Introduction: The risk factors encountered in the work of paramedics include ergonomic, physical, psychological, and biochemical factors. This study identifies discomforts experienced by paramedics during medical procedures in ambulances, emphasizing their negative impact on musculoskeletal load and forming the basis for ergonomic and organizational recommendations. Methods: The study employed non-invasive MyoMotion and EMG methods to measure musculoskeletal strain during typical stationary and transit medical procedures. Results: Preliminary results showed musculoskeletal overloads resulting from paramedics assuming forced positions during medical procedures on trauma patients. Some of these positions, especially while the ambulance was in motion, were characterized by a high risk of injury. Conclusions: An ergonomic ambulance interior can help reduce the risk of injuries during medical procedures.

Ictal central apnoea is a feature of focal temporal seizures. It is implicated as a risk factor for sudden unexpected death in epilepsy (SUDEP). Here we study seizure-related apnoeas in two different models of experimental seizures, one chronic and one acute, in adult genetically-unmodified rats, to determine mechanisms of seizure-related apnoeas. Under general anaesthesia rats receive sensors for nasal temperature, hippocampal and/or neocortical potentials, and ECG or EMG for subsequent tethered video-telemetry. Tetanus neurotoxin (TeNT), injected into hippocampus during surgery, induces a chronic epileptic focus. Other implanted rats receive intraperitoneal pentylenetetrazol (PTZ) to evoke acute seizures. In chronically epileptic rats, convulsive seizures cause apnoeas (9.9 ± 5.3 s; 331 of 730 convulsive seizures in 15 rats), associated with bradyarrhythmias. Absence of EEG and ECG biomarkers exclude obstructive apnoeas. All eight TeNT-rats with diaphragm EMG have apnoeas with no evidence of obstruction, and have apnoea EMGs significantly closer to expiratory relaxation than inspiratory contraction during pre-apnoeic respiration, which we term “atonic diaphragm”. Consistent with atonic diaphragm is that the pre-apnoeic nasal airflow is expiration, as it is in human ictal central apnoea. Two cases of rat sudden death occur. One, with telemetry to the end, reveals a lethal apnoea, the other only has video during the final days, which reveals cessation of breathing shortly after the last clonic epileptic movement. Telemetry following acute systemic PTZ reveals repeated seizures and seizure-related apnoeas, culminating in lethal apnoeas; ictal apnoeas are central – in 8 of 35 cases diaphragms initially contract tonically for 8.5 ± 15.0 s before relaxing, in the 27 remaining cases diaphragms are atonic throughout apnoeas. All terminal apnoeas are atonic. Differences in types of apnoea due to systemic PTZ in rats (mainly atonic) and mice (tonic) are likely species-specific. Certain genetic mouse models have apnoeas caused by tonic contraction, potentially due to expression of epileptogenic mutations throughout the brain, including in respiratory centres, in contrast with acquired focal epilepsies. We conclude that ictal apnoeas in the rat TeNT model result from atonic diaphragms. Relaxed diaphragms could be particularly helpful for therapeutic stimulation of the diaphragm to help restore respiration.

Superimposing neuromuscular electrical stimulation (NMES) on voluntary contractions has proven to be highly effective for improving muscle strength and performance. These improvements might involve specific adaptations occurring at cortical and spinal level. The effects of NMES on corticospinal activation seem to be frequency dependent and differ between upper and lower limb muscles. The aim of this study was to investigate acute responses in spinal excitability, as measured by H-reflex amplitude of flexor carpi radialis (FCR) and soleus (SOL) muscles, after NMES superimposed on voluntary contractions (NMES + ISO) at two different pulse frequencies (40 and 80 Hz). Conditions involved fifteen intermittent contractions at submaximal level. Before and after each condition, H-reflexes were elicited in FCR and SOL muscles.H-reflex amplitudes increased in FCR and SOL following both NMES + ISO at 40 and 80 Hz. The potentiation of the H-reflex was greater following the 40 Hz condition compared to 80 Hz, although no differences between muscles emerged.These findings indicated that superimposing NMES has an excitatory effect on spinal motoneurons in both upper and lower limb muscles with an overall greater response after low frequency NMES. Such facilitation could be associated to enhanced somatosensory stimuli conjunctly with higher supraspinal downward commands.

How cortical oscillations are involved in the coordination of functionally coupled muscles and how this is modulated by different movement contexts (static vs dynamic) remains unclear. Here, this is investigated by recording high-density electroencephalography (EEG) and electromyography (EMG) from different forearm muscles while healthy participants (n = 20) performed movement tasks (static and dynamic posture holding, and reaching) with their dominant hand. When dynamic perturbation was applied, beta band (15–35 Hz) activities in the motor cortex contralateral to the performing hand reduced during the holding phase, comparative to when there was no perturbation. During static posture holding, transient periods of increased cortical beta oscillations (beta bursts) were associated with greater corticomuscular coherence and increased phase synchrony between muscles (intermuscular coherence) in the beta frequency band compared to the no-burst period. This effect was not present when resisting dynamic perturbation. The results suggest that cortical beta bursts assist synchronisation of different muscles during static posture holding in healthy motor control, contributing to the maintenance and stabilisation of functional muscle groups. Theoretically, increased cortical beta oscillations could lead to exaggerated synchronisation in different muscles making the initialisation of movements more difficult, as observed in Parkinson's disease.

This study investigated the effect of different resistance increments during warm-up on snatch performance of male weightlifters. Nine male college weightlifters were recruited. The 3 warm-up protocols were performed every 7 days with a randomized order: 1. Power snatch exercise with 10 % resistance increment (50 %, 60 %, 70 %, and 80 % of one-repetition maximum); 2. Power snatch exercise with 15 % resistance increment (50 %, 65 %, and 80 % of one-repetition maximum); 3. Self-selected resistance increment. Participants were tested based on 85 % maximum weight snatch after warm-up. Snatch performance was measured using peak vertical ground reaction force. Postural stability was measured using center-of-pressure displacement. Activation of seven shoulder, back, and leg muscles was measured using electromyography on the dominant side. In snatch performance, the 10 % increment protocol had a significantly higher peak vertical ground reaction force during the second-pull phase than the 15 % increment (d = 0.92, p

Data collection process: This dataset includes running biomechanics measured using an instrumented treadmill combined with three- dimensional motion capture and surface muscle activation among 19 healthy participants (10 males, 9 females, mean ± SD age 23.6 ± 3.7 years, body height 174.9 ± 9.2 m; body mass 67.2 ± 10.4 kg) of various performance levels (untrained to Olympic level athlete). Running biomechanics were measured during thirteen different treadmill running conditions that included five speeds (2.78, 3.0, 3.33, 4.0 and 5.0 m·s−1), four gradients (-6, -3, +3, +6°), three cadences (preferred, ± 10 steps·min−1), and a condition with forward trunk lean. Dataset: Both raw data (.C3D files that include the 3D positions of the markers, ground reaction forces, and surface muscle activation) and processed data (joint angles, joint moments, muscle forces, joint contact forces, all analysed using OpenSim 3.3 musculoskeletal modelling software) are available. Standard subject characteristics such as height and body mass are also available. Reuse potential: The data can be re-used for various purposes including model validation studies, studies that aim to investigate biomechanical outcomes in specific running conditions, and as a reference database of running biomechanics across various conditions in healthy young non-injured individuals.

Hand Gesture Recognition (HGR) using electromyography (EMG) signals is a challenging problem due to the variability and noise in the signals across individuals. This study addresses this challenge by examining the effect of incorporating a post-processing algorithm, which filters the sequence of predictions and removes spurious labels, on the performance of a HGR model based on spectrograms and Convolutional Neural Networks (CNN). The study also compares CNN vs CNN-LSTM to assess the influence of the memory cells on the model. The EMG-EPN-612 dataset, which contains measurements of EMG signals for 5 hand gestures from 612 subjects, was used for training and testing. The results showed that the post-processing algorithm increased the recognition accuracy by 41.86% for the CNN model and 24.77% for the CNN-LSTM model. The inclusion of the memory cells increased accuracy by 3.29%, but at the cost of 53 times more learnables. The CNN-LSTM model with post-processing achieved a mean recognition accuracy of 90.55% (SD=9.45%). These findings suggest new paths for research in HGR architectures beyond the traditional focus on the classification and feature extraction stages. For reproducibility purposes, we made publicly available the source code in Github.

Athletic development centers on optimizing performance, including technical skills and fundamental motor abilities such as strength and speed. Parameters such as maximum contraction force and rate of force development, influence athletic success, although performance gains become harder to achieve as athletic abilities increase. Non-invasive transcranial direct current stimulation of the cerebellum (CB-tDCS) has been used successfully to increase force production in novices, although the potential effects in athletes remain unexplored. The present study examined the effects of CB-tDCS on maximum isometric voluntary contraction force (MVCiso) and isometric rate of force development (RFDiso) during a bench press task in well-trained athletes. 21 healthy, male, strength-trained athletes participated in a randomized, sham-controlled, double-blinded crossover design. Each participant completed the isometric bench press (iBP) task on two separate days, with at least 5 days between sessions, while receiving either CB-tDCS or sham stimulation. Electromyography (EMG) recordings of three muscles involved in iBP were acquired bilaterally to uncover differences in neuromuscular activation and agonist-antagonist co-contraction between conditions. Contrary to our hypothesis, no significant differences in MVCiso and RFDiso were observed between CB-tDCS and sham conditions. Furthermore, no tDCS-induced differences in neuromuscular activation or agonist-antagonist co-contraction were revealed. Here, we argue that the effects of CB-tDCS on force production appear to depend on the individual's training status. Future research should study individual differences in tDCS responses between athletes and novices, as well as the potential of high-definition tDCS for precise brain region targeting to potentially enhance motor performance in athletic populations.

Investigation of the factors explaining individual differences in the acquisition of expert reading skills has become of particular interest these last decades. Non-verbal abilities, such as visual attention and executive functions play an important role in reading acquisition. Among those non-verbal factors, error-monitoring, which allows one to detect one's own errors and to avoid repeating them in the future, has been reported to be impaired in dyslexic readers. The present three-year longitudinal study aims at determining whether error-monitoring efficiency evaluated before and during reading instruction could improve the explanation of reading skills. To do so, 85 children will be followed from the last year of kindergarten to the second grade. The classic predictors of reading will be assessed at each grade level. Error-monitoring indices in domain-general and reading-related contexts will be derived from EMG data recorded during a Simon task in kindergarten and during both a Simon and a lexical decision tasks in the first and second grades. Findings concerning the role of error-monitoring on reading skills are expected to have an important impact on reading instruction to prevent reading difficulties in at-risk children and improve remediation to help children with reading difficulties.

This study aimed to develop an automatic diagnostic scheme for bruxism, a sleep-related disorder characterized by teeth grinding and clenching. The aim was to improve on existing methods, which have been proven to be inefficient and challenging. We utilized a novel hybrid machine learning classifier, facilitated by the Weka tool, to diagnose bruxism from biological signals. The study processed and examined these biological signals by calculating the power spectral density. Data were categorized into normal or bruxism categories based on the EEG channel (C4-A1), and the sleeping phases were classified into wake (w) and rapid eye movement (REM) stages using the ECG channel (ECG1-ECG2). The classification resulted in a maximum specificity of 93% and an accuracy of 95% for the EEG-based diagnosis. The ECG-based classification yielded a supreme specificity of 87% and an accuracy of 96%. Furthermore, combining these phases using the EMG channel (EMG1-EMG2) achieved the highest specificity of 95% and accuracy of 98%. The ensemble Weka tool combined all three physiological signals EMG, ECG, and EEG, to classify the sleep stages and subjects. This integration increased the specificity and accuracy to 97% and 99%, respectively. This indicates that a more precise bruxism diagnosis can be obtained by including all three biological signals. The proposed method significantly improves bruxism diagnosis accuracy, potentially enhancing automatic home monitoring systems for this disorder. Future studies may expand this work by applying it to patients for practical use.

The COVID-19 pandemic resulting from the SARS-CoV-2 virus is in its third year. There is continuously evolving information regarding its pathophysiology and its effects on the nervous system. Clinical neurophysiology techniques are commonly employed to assess for neuroanatomical localization and/or defining the spectrum of neurological illness. There is an evolving body of literature delineating the effects of the SARS-CoV-2 virus on the nervous system as well as para-immunization responses to vaccination against this virus. This review focuses on the use of neurophysiological diagnostic modalities in the evaluation of potential acute and long-term neurological complications in patients that experience direct infection with SARS-CoV-2 and analyzes those reports of para-immunization responses to vaccination against the SARS-CoV-2 virus. The neurophysiological modalities to be discussed include electroencephalography (EEG), evoked potentials (EPs), nerve conduction studies and electromyography (EMG/NCV), autonomic function tests, transcranial magnetic stimulation (TMS) and Transcranial Doppler ultrasound (TCD).

Objective: To compare the utility of MUNIX (motor unit number index) with needle EMG in characterizing motor unit (MU) properties in the biceps brachii (BB) muscle in subjects with remote polio. Methods: Thirty subjects suffering from remote polio were investigated with MUNIX and needle EMG, all with Macro EMG and 16 of these subjects with concentric needle EMG. Results: Both MUNIX and the needle EMG methods showed abnormal results. Fiber density (FD) was the most sensitive parameter for showing signs of reinnervation. At a group level, the methods showed neurogenic findings, but there was no correlation between the results of the MUNIX and needle EMG investigations. Conclusions: Both MUNIX and needle EMG are valuable methods for measuring neurogenic involvement in the BB muscle. However, there was a lack of correlation between the MUNIX and needle EMG findings. The cause for this missing correlation may be multifactorial as there are several differences between the methods. Significance: The reason for the lack of correlation between the MUNIX and needle EMG results is discussed. By combining the needle and surface recorded methods one can obtain more information on the denervation and reinnervation process compared to using just one of the methods alone.

Joint moment is the resultant force of limb movements. However, estimation methods for joint moments using surface electromyography frequently use joint angles instead of limb angles. The limb angle in joint moment estimation using electromyography could clarify the effects of muscle activity on the limbs: acceleration, deceleration, or stabilization. No study has quantified the comprehensive relationship between limb movement, muscle activity, and joint moment. This study aimed to determine the influencing factors for ankle-joint moment and knee-joint moment in the sagittal plane among muscle activities and parameters related to limb movements during half squat and gait. This study included 29 healthy adults (16 female participants, 21.1 ± 2.09 years). Using inertial measurement units, thigh, shank, and foot inclination angles and angular accelerations were calculated as the parameters of limb movements. Muscle activations of the biceps femoris long head, rectus femoris, gastrocnemius, and tibialis anterior were measured. Ankle joint moment and knee-joint moment were measured using a three-dimensional motion capture system and two force plates. Regression models showed high accuracy in measuring ankle-joint moment during a half squat and gait (R2f = 0.92, 0.97, respectively) and knee-joint moment during a half squat (R2f = 0.98), but not knee-joint moment during gait (R2f = 0.63). However, only a maximum of five parameters were selected from muscle activities and limb angular information. Tibialis anterior and gastrocnemius activity were the largest contributors to ankle-joint moment during a half squat and gait, respectively, while muscle activities were not directly reflected in the knee-joint moment during either movement. Consideration of the interrelationships among limb movement, muscle activity, and joint moment is required when adjusting joint movements according to the target and aim of the therapeutic interventions.

Purpose: Postural control deteriorates with age, especially under dual-task conditions. It is currently unknown how a challenging virtual reality weight-shifting task affects lower back muscle activity. Hence, this study investigated erector spinae neuromuscular control during mediolateral weight-shifting as part of an exergame during single- (ST) and dual-task (DT) conditions in young and older adults. Methods: Seventeen young and 17 older adults performed mediolateral weight-shifts while hitting virtual wasps in a virtual environment with and without a serial subtraction task (DT). Center of mass position was recorded in real-time using 3D motion capturing. Electromyography recorded bilateral activation of the lumbar longissimus and iliocostalis muscles. Results: Weight-shifting (p

Biological systems, composed of various interrelated components, are nonlinear systems. Improved disease diagnosis and the application of efficient treatment and therapeutic aids are the direct outcomes of possessing a deep understanding of such systems. Therefore, by employing diverse biological system simulations and subsequently analyzing their responses and characteristics, we can diagnose diseases. In this particular study, a novel stimulation method was utilized for the first time, employing the Rossler equation, to record the electromyogram (EMG) signals of the biceps muscle in ten participants. The presented dataset enables the extraction of biological, computational, and chaotic features, which can be utilized for disease classification and diagnosis. Furthermore, this dataset can be employed for the training, validation, and testing of neural networks.

Stroke is a common worldwide health problem and a crucial contributor to gained disability. The abilities of people, who are subjected to stroke, to live independently are significantly affected since affected upper limbs' functions are essential for our daily life. This review article focuses on emerging trends in BCI-controlled rehabilitation techniques based on EMG, EEG, or EGM + EEG signals in the last few years. Working on developing rehabilitation robotics, is considered a wealthy scientific area for researchers in the last period. There is a significant advantage that the human acquires from the interaction between the machine and his body, rehabilitation for a patient's limb is very important to get the body limb recovery, and this is what is provided mostly by applying robotic devices.

Balance-correcting responses are fast, accurate, and functionally- and directionally-specific. However, there remains a lack of clarity in the literature as to how balance-correcting responses are organized, perhaps due to use of various perturbation methods. This study investigated the differences in neuromuscular organization of balance-correcting responses induced with platform-translation (PLAT) and upper body cable-pull (PULL) methods. Healthy males (n = 15; age: 24.3 ± 3.0 years) underwent unexpected forward and backward PLAT and PULL perturbations of equivalent intensity. EMG of leg, thigh, and trunk anterior and posterior muscles was recorded bilaterally during forward-stepping trials. Muscle activation latencies were calculated with respect to perturbation initiation. Repeated measures ANOVAs tested for differences in muscle activation latencies between perturbation methods and body sides (anterior/posterior muscles, swing/stance limb sides); Holm-Bonferroni sequentially rejective procedure adjusted alpha during multiple comparisons. Anterior muscle activation latencies were similar between methods (∼210 ms). During PLAT trials, posterior muscles demonstrated symmetrical distal-proximal activation between 70 ms and 260 ms, bilaterally. During PULL trials, stance-limb side posterior muscles demonstrated proximal-distal activation 70–130 ms; the activation latencies (∼80 ms) were not different between the stance-limb side posterior muscles. Previous examinations of method comparisons have examined results across publications, and generally have not accounted for different stimulus characteristics. This study revealed markedly different neuromuscular organization of balance-correcting responses to two different perturbation methods that utilized, importantly, equivalent perturbation intensity. Interpretation of functional balance recovery responses requires clear understanding of the intensity and nature of the perturbation.

This study investigates the effect of different normalisation methods on muscle synergy extraction from EMG data collected while walking in typically developing young people. Six methods were evaluated: Raw, Within-Trial Maximum, Inter-Trial Maximum, Task-Specific Maximum, Magnitude Percentile, and Unit Variance. Eighteen healthy children aged 8-15 participated, performing walking trials while their EMG signals were recorded and processed. Synergies were extracted using non-negative matrix factorisation, and the influence of normalisation methods on synergy complexity, structure, and activation coefficients was assessed. Normalisation choice significantly influenced synergy number, structure, and temporal characteristics. TSM and ITM methods yielded more consistent synergies, while MP and WTM exhibited greater variability. This study highlights the importance of selecting appropriate normalisation methods for robust muscle synergy analyses, enhancing understanding of motor control strategies, and contributing to a unified processing workflow., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Mental fatigue can affect cognitive function and interfere with motor performance. We examined if mental fatigue affected gait through age-specific modulation of wavelet-based time-frequency intermuscular beta-band coherence in muscles while walking on a treadmill at 1.2 m·s-1. The Psychomotor Vigilance Task, and the AX-Continuous Performance and the Stroop tests were used to induce mental fatigue in groups of healthy young and older participants. Mental fatigue reduced stance time, stride length, and marginally step width and increased cadence, stride length and stance time variability. In older compared with young participants before the induction of mental fatigue, wavelet-based time-frequency intermuscular beta-band coherence measured during walking was lower in the tibialis-peroneus and tibialis-gastrocnemius muscle pairs in specific phases of the gait cycle. In both age groups, after induction of mental fatigue, selected clusters of wavelet-based time-frequency intermuscular beta-band coherence measured during walking increased in the biceps-semitendinosus, rectus-vastus, tibialis-peroneus, gastrocnemius-soleus, and tibialis-gastrocnemius muscle pairs. In conclusion, we observed that while old age might weaken oscillatory coupling between selected ankle muscle pairs during gait, reflecting a certain level of impairment in the descending drive to these muscles, wavelet-based time-frequency intermuscular beta-band coherence measured during gait after mental fatigue migth increase independent of age., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Affective modulation of startle reflex (AMSR) is a widely used experimental tool for assessing emotional reactivity. Previous research has shown inconsistent findings of emotional reactivity in amplitude in bipolar patients (BP). This study examined emotional reactivity (ER) in euthymic BP compared to healthy controls using both subjective and objective measures., Method: This study compared ER between 33 euthymic BP (I and II) and 35 healthy controls. Subjective experiences, valence, and arousal scores were assessed using the Self-Assessment Manikin. Objective measures included startle reflex parameters - amplitude, area, and latency - from the orbicularis oculi muscle via electromyography. To assess the AMSR, pictures of varying emotional valences from the International Affective Picture System were used during acoustic stimulation., Results: A significant picture category effect was observed in the subjective picture evaluation; however, no substantial group effect or picture category-group interaction was detected. In the controls, picture categories exerted a significant effect on amplitude, but did not in euthymic BP. A linear pattern of startle amplitude across different picture categories was evident in the control group but not in patients. Analyses of the area did not reveal significant group differences. Onset latency was also similar between groups., Conclusion: This study indicates impaired emotional processing in euthymic individuals with bipolar disorder, as shown by altered startle reflex measurements. Future research with larger samples and consideration of bipolar disorder subtypes is needed to explore these findings further., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Non-invasive brain stimulation (NIBS) experiments involve many recurring procedures that are not sufficiently standardized in the community. Given the diversity in experimental design and experience of the investigators, automated but yet flexible data collection and analysis tools are needed to increase objectivity, reliability, and reproducibility of NIBS experiments. The Brain Electrophysiological recording and STimulation (BEST) Toolbox is a MATLAB-based, open-source software with graphical user interface that allows users to design, run, and share freely configurable multi-protocol, multi-session NIBS studies, including transcranial magnetic, electric, and ultrasound stimulation (TMS, tES, TUS). Interfacing with a variety of recording and stimulation devices, the BEST toolbox analyzes EMG and EEG data, and configures stimulation parameters on-the-fly to facilitate closed-loop protocols and real-time applications. Its functionality is continuously expanded and includes e.g., TMS motor hotspot search, threshold estimation, motor evoked potential (MEP) and TMS-evoked EEG potential (TEP) measurements, dose-response curves, paired-pulse and dual-coil TMS, rTMS interventions.

Objective: We investigated how clinical neurophysiological testing can help distinguish tremor and myoclonus and their subtypes. Methods: We retrospectively analysed clinical and neurophysiological data from patients who had undergone polymyography (EMG + accelerometry) to diagnose suspected tremor or myoclonus. We show a systematic approach, which includes contraction pattern, rhythm regularity, burst duration and evidence of cortical drive. Results: We detected 773 patients in our database, of which 556 patients were ultimately diagnosed with tremor (enhanced physiological tremor n = 169, functional tremor n = 140, essential tremor n = 90, parkinsonism associated tremor n = 64, cerebellar tremor n = 19, Holmes tremor n = 12, dystonic tremor n = 8, tremor not further specified n = 9), 140 with myoclonus and 23 with a combination of tremor and myoclonus. Polymyography confirmed the presumptive diagnosis in the majority of the patients and led to a change of diagnosis in 287 patients (37%). Conversions between diagnoses of tremor and myoclonus occurred most frequently between enhanced physiological tremor, essential tremor, functional tremor and cortical myoclonus. Conclusions: Neurophysiology is a valuable additional tool in clinical practice to differentiate between tremor and myoclonus, and can guide towards a specific subtype. Significance: We show how the stepwise neurophysiological approach used at our medical center aids the diagnosis of tremor versus myoclonus.

Processing multiple channels of bioelectrical signals for bionic assistive robot volitional motion control is still a challenging task due to the interference of systematic noise, artifacts, individual bio-variability, and other factors. Emerging machine learning (ML) provides an enabling technology for the development of the next generation of smart devices and assistive systems and edging computing. However, the integration of ML into a robotic control system faces major challenges. This paper presents ML computing to process twelve channels of shoulder and upper limb myoelectrical signals for shoulder motion pattern recognition and real-time upper arm exoskeleton volitional control. Shoulder motion patterns included drinking, opening a door, abducting, and resting. ML algorithms included support vector machine (SVM), artificial neural network (ANN), and Logistic regression (LR). The accuracy of the three ML algorithms was evaluated respectively and compared to determine the optimal ML algorithm. Results showed that overall SVM algorithms yielded better accuracy than the LR and ANN algorithms. The offline accuracy was 96 ± 3.8% for SVM, 96 ± 3.8% for ANN, and 93 ± 6.3% for LR, while the online accuracy was 90 ± 9.1% for SVM, 86 ± 12.0% for ANN, and 85 ± 11.3% for LR respectively. The offline pattern recognition had a higher accuracy than the accuracy of real-time exoskeleton motion control. This study demonstrated that ML computing provides a reliable approach for shoulder motion pattern recognition and real-time exoskeleton volitional motion control.

Summary: Objective: Two techniques facilitate the transition in an alpine ski turn, extension (EXT) and flexion (FLEX). The purpose of this study is to compare NIRS, EMG, and RPE responses between EXT and FLEX in expert level skiers. Design: 24 Professional Ski Instructors of America Level III alpine ski instructors, examiners, and National Demonstration Team members completed one standardized run each of EXT and FLEX. A turn cycle, made of a right and left turn, was divided into four Phases. Methods: NIRS assessed HbO2 desaturation in the rectus femoris (RF) and vastus lateralis (VL). EMG was collected from the RF, VL, and gluteus medius (GM). Rating of Perceived Exertion (RPE, 0–10) assessed subjective exertion. Results: FLEX resulted in greater HbO2 desaturation in RF (−77.9 ​± ​21% vs. −67.5 ​± ​23%, p ​

The biological and pharmacological properties of natural polyphenols of the extract of Euterpe oleracea stone (EEOS) are associated with the central nervous system (CNS). To investigate the sedative and myorelaxant activity of EEOS in vivo, this study aimed to present the myorelaxant and sedative effects of EEOS in Wistar rats using spontaneous locomotor activity and motor electrophysiology. A total of 108 animals were used in the following experiments: a) behavioral tests (n = 27); b) electromyographic recordings of skeletal muscle (n = 27); c) respiratory muscle activity recordings (n = 27); d) cardiac muscle activity recordings (n = 27). The behavioral characteristics were measured according to the latency time of onset, the transient loss of posture reflex and maximum muscle relaxation. Electrodes were implanted in the gastrocnemius muscle and in the tenth intercostal space for electromyographic (EMG) signal capture to record muscle contraction, and in the D2 lead for electrocardiogram acquisition. After using the 300 mg/kg dose of EEOS intraperitoneally, a myorelaxant activity exhibited a lower frequency of contractility with an amplitude pattern of low and short duration at gastrocnemius muscle and intercostal muscle, which clearly describes a myorelaxant activity and changes in cardiac activity. The present report is so far the first study to demonstrate the myorelaxant activity of this extract, indicating an alternative route for açai stone valorization and its application in pharmaceutical fields.

In recent years, several studies have investigated upper-limb motion in a variety of scenarios including motor control, physiology, rehabilitation and industry. Such applications assess people’s kinematics and muscular performances, focusing on typical movements that simulate daily-life tasks. However, often only a limited interpretation of the EMG patterns is provided. In fact, rarely the assessments separate phasic (movement-related) and tonic (postural) EMG components, as well as the EMG in the acceleration and deceleration phases. With this paper, we provide a comprehensive and detailed characterization of the activity of upper-limb and trunk muscles in healthy people point-to-point upper limb movements. Our analysis includes in-depth muscle activation magnitude assessment, separation of phasic (movement-related) and tonic (postural) EMG activations, directional tuning, distinction between activations in the acceleration and deceleration phases. Results from our study highlight a predominant postural activity with respect to movement related muscular activity. The analysis based on the acceleration phase sheds light on finer motor control strategies, highlighting the role of each muscle in the acceleration and deceleration phase. The results of this study are applicable to several research fields, including physiology, rehabilitation, design of robots and assistive solutions, exoskeletons.

The acute and delayed phases of the functional recovery pattern after running exercise have been studied mainly in men. However, it seems that women are less fatigable and/or recover faster than men, at least when tested in isometric condition. After a 20 km graded running race, the influence of sex on the delayed phase of recovery at 2–4 days was studied using a horizontal ballistic force-velocity test. Nine female and height male recreational runners performed maximal concentric push-offs at four load levels a week before the race (PRE), 2 and 4 days (D2 and D4) later. Ground reaction forces and surface electromyographic (EMG) activity from 8 major lower limb muscles were recorded. For each session, the mechanical force-velocity-power profile (i.e. theoretical maximal values of force (F¯ 0), velocity (V¯ 0), and power (P¯ max)) was computed. Mean EMG activity of each recorded muscle and muscle synergies (three for both men and women) were extracted. Independently of the testing sessions, men and women differed regarding the solicitation of the bi-articular thigh muscles (medial hamstring muscles and rectus femoris). At mid-push-off, female made use of more evenly distributed lower limb muscle activities than men. No fatigue effect was found for both sexes when looking at the mean ground reaction forces. However, the force-velocity profile varied by sex throughout the recovery: only men showed a decrease of both V¯ 0 (p < 0.05) and P¯ max (p < 0.01) at D2 compared to PRE. Vastus medialis activity was reduced for both men and women up to D4, but only male synergies were impacted at D2: the center of activity of the first and second synergies was reached later. This study suggests that women could recover earlier in a dynamic multi-joint task and that sex-specific organization of muscle synergies may have contributed to their different recovery times after such a race.

The electromyography (EMG) signal provides insight into neuromuscular activity which is used in medical and technological fields. Traditional needle electrodes and surface electrodes have several drawbacks making them less suitable for portable and long-term use. In contrast, emerging capacitive electrodes offer promising features over the existing electrodes. Yet, the full potential of capacitive electrodes remains untapped due to the lack of comprehensive design optimization for consistently reliable signal quality. This study highlights the complex interplay of factors influencing correlation in capacitive EMG (cEMG) and wet surface EMG (wet sEMG) signals. The study emphasizes the importance of the surface area of capacitive electrodes, muscle force, preprocessing, and sampling frequency in understanding and improving the correlation between cEMG and wet sEMG signals, providing valuable insights for future research and applications in the field. The study reveals that the electrode area has no significant effect on the correlation. However, the correlation significantly depends on the muscle force. In addition, removing artifacts from the cEMG signal increases the correlation, especially for lower force where artifacts are significant. Again, oversampling the EMG signal above 800 Hz does not have any impact on increasing the correlation but the correlation decreases with higher inter-electrode distance (IED). In this research, the highest correlation of 82.89% (normalized-91.62%) between cEMG and sEMG has been achieved for high muscle force with a plate area of 4 cm 2 . Therefore, the capacitive electrode can be an alternative for EMG signal acquisition., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

We explore the effect of stress-recovery schedule on the cumulative creep response of lumbar tissues. Twelve participants performed a 48-minute protocol that consisted of 12 min of full trunk flexion and 36 min of upright standing. Two stress-recovery (work-rest) schedules were considered: a) three minutes of full trunk flexion followed by twelve minutes of upright standing (3:12), and b) one minute of full trunk flexion followed by four minutes of upright standing (1:4). Lumbar kinematics and EMG activity of erector spinae muscles were collected. Cumulative creep deformation was explored by considering the changes in peak lumbar flexion angles during full flexion and changes in the angles of flexion-relaxation (EMG-off) of the lumbar extensor musculature after the 48-minute protocol. The results of time-dependent lumbar flexion angle during full flexion revealed a noticeable creep response in both work-rest schedules, but the cumulative creep response was significantly greater in the 3:12 schedule (Δ3.5°) than in the 1:4 schedule (Δ1.6°). Similarly, the change in the EMG-off lumbar flexion angle in the 3:12 schedule was significantly greater than in the 1:4 schedule (Δ2.5° vs -Δ0.2°, respectively). These results indicate that the passive lumbar tissues recover their force producing capability more rapidly with shorter cycle times., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In primates, the parietal cortex plays a crucial role in hand-object manipulation. However, its involvement in object manipulation and related hand-muscle control has never been investigated in humans with a direct and focal electrophysiological approach. To this aim, during awake surgery for brain tumors, we studied the impact of direct electrical stimulation (DES) of parietal lobe on hand-muscles during a hand-manipulation task (HMt). Results showed that DES applied to fingers-representation of postcentral gyrus (PCG) and anterior intraparietal cortex (aIPC) impaired HMt execution. Different types of EMG-interference patterns were observed ranging from a partial (task-clumsy) or complete (task-arrest) impairment of muscles activity. Within PCG both patterns coexisted along a medio (arrest)–lateral (clumsy) distribution, while aIPC hosted preferentially the task-arrest. The interference patterns were mainly associated to muscles suppression, more pronounced in aIPC with respect to PCG. Moreover, within PCG were observed patterns with different level of muscle recruitment, not reported in the aIPC. Overall, EMG-interference patterns and their probabilistic distribution suggested the presence of different functional parietal sectors, possibly playing different roles in hand-muscle control during manipulation. We hypothesized that task-arrest, compared to clumsy patterns, might suggest the existence of parietal sectors more closely implicated in shaping the motor output.

Introduction: The application of botulinum toxin type A (BoNTA) is accelerating, and this includes the uncontrolled cosmetic use of the BoNTA. Diffusion of BoNTA can disturb neuromuscular transmission in several surrounding and distant muscles and result in clinical manifestations similar to myasthenia gravis (MG). Case presentations: We report two cases of patients referred for neurophysiological evaluation of suspected MG. A 55-year-old female who experienced dysphagia, dysarthria, right-sided ptosis, and neck extensor muscle weakness; and a 46-year-old male who presented with episodic double vision and right-sided ptosis. Both had the history of previous BoNTA use for cosmetic purposes and for the treatment of migraine before the presentation of their symptoms. In both cases examination revealed normal RNS, quite remarkably increased jitter, and signs of denervation and reinnervation in muscles surrounding the injection sites. After extensive neurophysiological evaluations, the primary cause of their symptoms was found to be related to previous BoNTA injections rather than a primary neuromuscular transmission disorder. It could also be concluded that patients do not automatically inform their physicians about cosmetic BoNTA use and they may not be aware of the potential risks associated with BoNTA therapy. Conclusions: The presented cases illustrate the neurophysiological findings in two patients with suspected MG after the use of BoNTA and emphasize the importance of inquiring about previous BoNTA injections and highlight that it is essential that patients are informed about possible side effects of BoNTA therapy.

Objective: To derive normal values from a lab’s own diagnostic studies, the e-norms method relies on the proper identification of the e-norms plateau to derive descriptive statistics of the variable under study. This work was undertaken to compare the inter and intra-rater reliability of visual identification of the plateau by different raters analyzing laboratory nerve conductions study data. Methods: Twenty raters were asked to visually identify the inflection points delineating an e-norms plateau to derive the Mean value of nerve conduction study laboratory data while blinded to the parameter they were analyzing. After a delay of 1–3 months, the same raters were asked to repeat some of the e-norms plateaus identification to assess delayed intra-rater reproducibility. Results: Mean values derived from the identified plateau data were compared between raters (inter-rater) using a two factor ANOVA without replication. For the immediate inter-rater no statistically significant difference was found between the Means obtained by the different raters. For the delayed intra-rater, differences were found between raters. Conclusions: This study suggests that visual identification of the e-norms plateau inflection point is reliable between raters but more research is needed to assess reproducibility for the same raters. Significance: E-norms is a promising method for deriving reference values using data that is available in most electrophysiology laboratories.

Purpose: Population aging and certain behaviors associated with modern life are contributing factors for the increasing incidence of degenerative cervical spine conditions (DCSC), and the number of cervical spine surgeries every year is. Our aim was to determine, with an original research protocol, the impact of ACDF and physiotherapy on the range of motion and EMG parameters of patients suffering from DCSC. Patients and Methods: Two comparable subgroups of 29 patients each were recruited for the present investigation. The first cohort was composed of ACDF patients, whereas the second cohort was composed by healthy subjects. Inclinometry/Range of Motion (RoM) analyses of the neck, and cervical muscles electromyography (EMG) were used to evaluate the neck mobility. We investigated the effects of physiotherapy on ROM and EMG results in order to identify possible significant differences between healthy subjects and ACDF patients. Results: A total of 58 patients were included in the final cohort. Extensive statistical analysis disclosed that higher NDI values were associated with a reduction of the Extension and Rotation movements, NDI scores, were found to be negatively associated to EMG voltages for Rotation, independently of the physiotherapy performed either. Extension, Lateral Bending, and Rotation showed significant improvement after just one session of physiotherapy, whereas Flexion and Extension proved to be those that contributed most to the overall neck mobility. Conclusion: The cervical spine fusion contributes to an overall reduction of cervical mobility. This data is confirmed by inclinometer and EMG parameters. Physiotherapy increases neck mobility thus possibly improving the clinical status of patients.

Surface Electromyography (sEMG) is the non-invasive measurement of skeletal muscle contraction bio-potentials. Measuring sEMG of a stimulated muscle can prove particularly difficult due to large scale and long lasting stimulation-induced artefacts: if an sEMG device does not account for such artefacts, its measurements can be swamped and components damaged. sEMG has been used in a wide range of clinical and biomedical fields, providing measures such as muscular fatigue and subject intent. The recording of sEMG can prove difficult due to signal contamination such as movement artefact and mains interference.There are very few commercial sEMG devices that contain protection against large stimulation voltages or measures to reduce artefact transient times. Furthermore, most commercial or research level designs are not open source; these designs are effectively an inflexible black box to researchers and developers.This research presents the design, test and validation of an open source sEMG design, able to record muscle bio-potentials concurrently to electrical stimulation. The open source, low-cost nature of the design provides accessibility to researchers without the time and cost associated with design development. The design has been tested on the forearms of four able-bodied subjects during 25 Hz constant current stimulation, and has been shown to record subject volitional sEMG and M-wave without saturation.

The MR-induced gradient artifact affects EMG recordings during simultaneous muscle BOLD/EMG acquisitions. However, no dedicated hardware can remove the gradient artifact easily, and alternative methods are expensive and time-consuming. This study aimed to develop three denoising methods requiring different processing levels and MR-compatible hardware. At two time points, surface EMG was recorded from the lower leg of 6 participants (50:50 sex ratio, age = 26.24.6 yrs., height = 173.59.2 cm, weight = 71.511.4 kg) using a plantar flexion-based block design consisting of 30s of rest followed by 30s of flexion for 5 min, under three conditions: inside the MRI bore, with and without a BOLD sequence (3 T, BOLD sequence, GRE EPI, 10 slices, 64×64 matrix, 2 mm thickness, and TE/TR/flip = 35/3000 ms/70), and outside the MRI environment. Simultaneous BOLD/EMG recordings were denoised using average artifact subtraction with three methods of artifact template creation, each having varying timing and hardware requirements. Method M1 builds the artifact template by recording the scanner triggers coming from the MRI; M2 creates the artifact template with a constant artifact period computed as TR/[number of slices]; M3 estimates the artifact template by looking at the periodicity of the gradient artifact located in the EMG recordings. Following postprocessing, SNR analysis was performed, comparing rest-to-flexion periods, to assess the efficacy of denoising methods and to compare differences between conditions. Linear mixed-effects models showed no significant differences in the mean SNR between denoising methods (p = 0.656). Furthermore, EMG SNR measurements were significantly affected by the magnetic environment (p < 0.05) but not by muscle fatigue over time (p = 0.975). EMG recordings contaminated with gradient artifacts during simultaneous BOLD/EMG can be efficiently denoised using all proposed methods, with two methods requiring no extra hardware. With minimal post-processing, EMG can easily be performed during muscle BOLD MRI studies., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: This study examined the effects of acute normoxic and hypoxic exposure on neuromuscular and hemodynamic physiological responses performed during dynamic step muscle actions., Methods: Thirteen recreationally active men (mean ± SD age: 21.2 ± 2.9 yrs) performed dynamic leg extensions unilaterally under Normoxic (FiO 2  = 21 %) and Hypoxic (FiO 2  = 13 %) conditions in a randomized order at 20 %, 40 %, 60 %, 80 %, and 100 % of their maximal strength. Electromyographic (EMG) amplitude, EMG frequency, (Oxygenated and Deoxygenated hemoglobin; Oxy Hb , Deoxy Hb) , Total hemoglobin (Total Hb ), and skeletal muscle tissue oxygenation status (StO 2 ) were measured from the vastus lateralis during all contractions., Results: There were no detectable differences in the neuromuscular responses between normoxia and hypoxia for EMG amplitude (p = 0.37-0.74) and frequency (p = 0.17-0.83). For EMG amplitude there were general increases with intensity (p < 0.01-0.03). EMG frequency remained similar from 20% to 80% and then increased at 100 % effort (p = 0.02). There was no significant difference in patterns of responses for Oxy Hb (p = 0.870) and Total Hb (p = 0.200) between normoxia and hypoxia. StO 2 (p = 0.028) decreased and Deoxy Hb (p = 0.006) increased under hypoxia compared to normoxia during dynamic step muscle actions performed in a randomized order., Conclusion: Unlike fatigue, acute hypoxemia in an unfatigued state does not impact the localized neuromuscular responses, but minimally impacts the hemodynamic responses., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Emotional mimicry plays an important role in social interaction and is influenced by social context, especially eye gaze direction. However, the neural mechanism underlying the effect of eye gaze direction on emotional mimicry is unclear. Here, we explored how eye gaze direction influenced emotional mimicry with a combination of electromyography (EMG) and electroencephalography (EEG) techniques, which may provide a more comprehensive measure. To do this, we recorded facial EMG and scalp EEG signals simultaneously while participants observed emotional faces (happy vs. angry) with direct or averted gaze. Then, we split the EEG trials into two mimicry intensity categories (high mimicry intensity, HMI vs. low mimicry intensity, LMI) according to EMG activity. The ERP difference between HMI and LMI EEG trials revealed four ERP components (P50, P150, N200 and P300), and the effect of eye gaze direction on emotional mimicry was prominent on P300 at P7 and P8. Moreover, we also observed differences in the effect of eye gaze direction on mimicry of happy faces and angry faces, which were found on P300 at P7, as well as P150 at P7 and N200 at P7 and Pz. In short, the present study isolated the neural signals of emotional mimicry with a new multimodal method, and provided empirical neural evidence that eye gaze direction affected emotional mimicry.

Surface Electromyography (EMG) and Inertial Measurement Unit (IMU) sensors are gaining the attention of the research community as data sources for automatic sign language recognition. In this regard, we provide a dataset of EMG and IMU data collected using the Myo Gesture Control Armband, during the execution of the 26 gestures of the Italian Sign Language alphabet. For each gesture, 30 data acquisitions were executed, composing a total of 780 samples included in the dataset. The gestures were performed by the same subject (male, 24 years old) in lab settings. EMG and IMU data were collected in a 2 seconds time window, at a sampling frequency of 200 Hz.

Response inhibition refers to the suppression of prepared or initiated actions. Typically, the go/no-go task (GNGT) or the stop signal task (SST) are used interchangeably to capture individual differences in response inhibition. On the one hand, factor analytic and conjunction neuroimaging studies support the association of both tasks with a single inhibition construct. On the other hand, studies that directly compare the two tasks indicate distinct mechanisms, corresponding to action restraint and cancellation in the GNGT and SST, respectively. We addressed these contradictory findings with the aim to identify the core differences in the temporal dynamics of the functional networks that are recruited in both tasks. We extracted the time-courses of sensory, motor, attentional, and cognitive control networks by group independent component (G-ICA) analysis of electroencephalography (EEG) data from both tasks. Additionally, electromyography (EMG) from the responding effector muscles was recorded to detect the timing of response inhibition. The results indicated that inhibitory performance in the GNGT may be comparable to response selection mechanisms, reaching peripheral muscles at around 316 ​ms. In contrast, inhibitory performance in the SST is achieved via biasing of the sensorimotor system in preparation for stopping, followed by fast sensory, motor and frontal integration during outright stopping. Inhibition can be detected at the peripheral level at 140 ​ms after stop stimulus presentation. The GNGT and the SST therefore seem to recruit widely different neural dynamics, implying that the interchangeable use of superficially similar inhibition tasks in both basic and clinical research is unwarranted.

Background: Essential tremor (ET) is one of the most common hyperkinetic movement disorders. Previous research into the pathophysiology of ET suggested underlying cerebellar abnormalities. Objective: In this study, we added electromyography as an index of tremor intensity to functional Magnetic Resonance Imaging (EMG-fMRI) to study a group of ET patients selected according to strict criteria to achieve maximal homogeneity. With this approach we expected to improve upon the localization of the bilateral cerebellar abnormalities found in earlier fMRI studies. Methods: We included 21 propranolol sensitive patients, who were not using other tremor medication, with a definite diagnosis of ET defined by the Tremor Investigation Group. Simultaneous EMG-fMRI recordings were performed while patients were off tremor medication. Patients performed unilateral right hand and arm extension, inducing tremor, alternated with relaxation (rest). Twenty-one healthy, age- and sex-matched participants mimicked tremor during right arm extension. EMG power variability at the individual tremor frequency as a measure of tremor intensity variability was used as a regressor, mathematically independent of the block regressor, in the general linear model used for fMRI analysis, to find specific tremor-related activations. Results: Block-related activations were found in the classical upper-limb motor network, both for ET patients and healthy participants in motor, premotor and supplementary motor areas. In ET patients, we found tremor-related activations bilaterally in the cerebellum: in left lobules V, VI, VIIb and IX and in right lobules V, VI, VIIIa and b, and in the brainstem. In healthy controls we found simulated tremor-related activations in right cerebellar lobule V. Conclusions: Our results expand on previous findings of bilateral cerebellar involvement in ET. We have identified specific areas in the bilateral somatomotor regions of the cerebellum: lobules V, VI and VIII.

We evaluated the role of visual stimulation on postural muscles and the changes in the center of pressure (CoP) during standing posture in expert and amateur basketball players. Participants were instructed to look at a fixation point presented on a screen during foveal, peripheral, and full field optic flow stimuli. Postural mechanisms and motor strategies were assessed by simultaneous recordings of stabilometric, oculomotor, and electromyographic data during visual stimulation. We found significant differences between experts and amateurs in the orientation of visual attention. Experts oriented attention to the right of their visual field, while amateurs to the bottom-right. The displacement in the CoP mediolateral direction showed that experts had a greater postural sway of the right leg, while amateurs on the left leg. The entropy-based data analysis of the CoP mediolateral direction exhibited a greater value in amateurs than in experts. The root-mean-square and the coactivation index analysis showed that experts activated mainly the right leg while amateurs the left leg. In conclusion, playing sports for years seems to have induced some strong differences in the standing posture between the right and left sides. Even during non-ecological visual stimulation, athletes maintain postural adaptations to counteract the body oscillation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background/Objective: The purpose of this study was to analyze muscle activation when performing push-ups under different stability conditions. Methods: Physically fit young male university students (N = 30) performed five push-ups under stable conditions (on the floor) and using four unstable devices (wobble board, stability disc, fitness dome, and the TRX Suspension Trainer). The push-up speed was controlled using a metronome, and the testing order was randomized. The average amplitudes of the electromyographic (EMG) root mean square of the anterior deltoid (DELT), serratus anterior (SERRA), lumbar multifidus (LUMB), and rectus femoris (FEM) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Results: No significant differences were found for the DELT [F(4,112) = 1.978; p = 0.130] among the conditions. However, statistically significant differences were found among the different conditions for the SERRA [F(4,60) = 17.649; p

Understanding the consequences and ecological relevance of muscle fatigue is important to guide the development of strategies to preserve independence. However, few studies have examined walking-related fatigue and the effects on walking instability. Our purpose was to investigate the effects of prolonged walking on leg muscle activity and vulnerability to balance perturbations. Eighteen healthy young adults completed a 30-min walking trial at their preferred walking speed while leg muscle activities were recorded. Before and after the 30-min walk, participants responded to five 5% body weight lateral force perturbations. Time-frequency analysis with wavelet transformation and principal component analyses assessed neuromuscular adaptations of muscles to prolonged walking. Following prolonged walking, we observed a time-dependent increase in EMG intensities at slower frequencies for the soleus and tibialis anterior and a decrease in mean amplitudes for the soleus, lateral gastrocnemius, and semitendinosus. Mean mediolateral CoM displacement following perturbations averaged 21% larger after the 30-min walk. Our results suggest that walking for 30 min at a comfortable speed elicits complex neuromuscular adaptations indicative of local muscle fatigue and an increased vulnerability to walking balance perturbations. These findings could inform fatigue monitoring systems or walking assistive devices aimed at reducing walking-related fatigue and maintaining independent mobility., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Trunk extensor muscle fatigue typically manifests as a decline in spectral content of surface electromyography. However, previous research on the relationship of this decline with trunk extensor muscle endurance have shown inconsistent results. The decline of spectral content mainly reflects the decrease in average motor unit action potential conduction velocity (CV). We evaluated whether the rate of change in CV, as well as two approaches employing the change in spectral content, are related to trunk extensor muscle endurance. Fourteen healthy male participants without a low-back pain history performed a non-strictly controlled static forward trunk bending trial until exhaustion while standing. For 13 participants, physiologically plausible CV estimates were obtained from high-density surface electromyography bilaterally from T6 to L5. Laterally between L1 and L2, the linear rate of CV change was strongly correlated to endurance time (R 2  = 0.79), whereas analyses involving the linear rate of change in spectral measures showed a lower (R 2  = 0.38) or no correlation. For medial electrode locations, estimating CV and its relationship with endurance time was less successful, while the linear rate of change in spectral measures correlated moderately to endurance time (R 2  = 0.44; R 2  = 0.56). This study provides guidance on monitoring trunk extensor muscle fatigue development using electromyography., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

There are significant differences in duration and intensity of clinical neurophysiology specialty training within the countries of the Europe, Middle East and Africa Chapter of the International Federation of Clinical Neurophysiology. We address these differences by proposing recommendations which may facilitate harmonisation of training and education within the Chapter. They arose from two workshops whose recommendations were then circulated widely within national societies in the Chapter for feedback and for consensus. The recommendations are applicable to clinical neurophysiology as a medical monospecialty and/or as a subspecialty (usually of neurology). We make a number of recommendations on governance and regulation of training, on the requirements for competence and the numbers of various examinations and tests performed by trainees, some under supervision. We also recommend a modular approach considering primary and complementary modules. Primary modules are electroencephalography, electromyography, nerve conduction studies and evoked potentials, while complementary ones include sleep analysis, intraoperative monitoring, small fibre testing, peripheral nerve and muscle ultrasound, intracortical recordings, and analysis of movement disorders. It is recommended that national examinations should include a variety of techniques to assess knowledge and judgement, practical skills, teamwork, communication skills, as well as safety and quality. The aim of the suggested recommendations is to harmonize clinical neurophysiology training in the member societies throughout the Chapter. It is realised that this may mean that the numbers for competence are aspirational for some, though ways to mitigate this, for instance through supranational training centres, are also discussed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 International Federation of Clinical Neurophysiology. All rights reserved.)