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Introduction: Unlike the most common training approaches for bodybuilding, powerlifting programs are generally based on maximum and submaximal loads, putting enormous stresses on the lumbar spine. The flexion relaxation phenomenon evaluation is a clinical tool used for low back pain (LBP) assessment. This study aimed to evaluate the role of the flexion relaxation phenomenon in the analysis of LBP in the powerlifters. Methods: Healthy professional powerlifters participated in the study. In fact, we divided the participants into a LBP-low-risk group and a LBP-high-risk group, based on a prior history of LBP. Outcome measures included flexion relaxation ratio (FRR) and trough surface electromyography collected during trunk maximum voluntary flexion; furthermore, during a bench press lifting, we measured the height of the arched back (ARCH), using a camera and the Kinovea video editing software, to consider a potential correlation with the risk of LBP. Results: We included a group of 18 male (aged 24–39 y) powerlifters of 93 kg category. We measured a nonsignificant mean difference of ARCH between low-risk LBP group and high-risk LBP subjects. Curiously, maximum voluntary flexions were both above the threshold of 3.2 μV; therefore, with an absence of appropriate myoelectric silence, on the contrary, the FRR ratios were higher than 9.5, considering the presence of the phenomenon, exclusively for the low-risk group. The lumbar arched back measurement data did not report any association with the LBP risk, regarding the maximum voluntary flexion value, and even more than the FRR there is a relationship with the presence or the absence of LBP risk. Conclusions: FRR could be considered as a useful parameter for studying the risk of LBP in powerlifting. The FRR index not only refers to the possible myoelectric silence of the lumbar muscles in trunk maximum forward flexion but also takes into account the energy value delivered by the lumbar muscles during the flexion. Furthermore, we can indicate that the size of the powerlifter ARCH may not be a determining factor in the occurrence of LBP. [ABSTRACT FROM AUTHOR]

Objective: To explore the neuromuscular control mechanism and quantifying the fatigue response during bench press exercise is important references to prescribe an appropriate exercise program. However, current literature struggles to provide a concrete conclusion on the changes of intermuscular EMG-EMG coupling between synergistic and antagonist muscles during the exercise. Thus, the current study was designed to reveal fatigue-related changes of intermuscular EMG-EMG coupling during bench press exercise. Methods: Thirty-one healthy male participants performed a bench press exercise on the Smith machine at 60% One Repetition Maximum (1RM) workload to exhaustion, while surface electromyographic signals (sEMG) were collected from triceps brachii (TB), biceps brachii (BB), anterior deltoid (AD), posterior deltoid (PD), and pectoralis major (PM). Surface EMG signals were divided into the first half and second half of the bench press exercise. Phase synchronization index (PSI) was calculated between sEMG of synergistic muscle pairs AD-TB, AD-PM and antagonist muscle pairs BB-TB, AD-PD. Results: EMG power of TB, AD, PD, PM muscles in alpha (8–12 Hz) frequency band and EMG power of each muscle in beta (15–35 Hz), and gamma (35–60 Hz) frequency bands were all increased during the second half of contraction compared with the first half of contraction. PSI of gamma frequency band was significantly decreased in BB-TB muscle pair while EMG-EMG coupling of AD-TB in gamma frequency band was significantly increased during the second half of contraction compared to the first half of contraction. Conclusions: The results indicated a decrease of interconnection between synchronized cortical neurons and the motoneuron pool of BB and TB, and an increase of interconnection between AD-TB muscles during fatiguing bench press exercise at 60% 1RM workload. The changes of intermuscular coupling may be related to the supraspinal modulations to compensate for the decrease of muscle force as well as a result of unbalanced changes of agonist and antagonist muscle contractility. [ABSTRACT FROM AUTHOR]

Objectives: Occlusal splints are the main therapeutic choice in the treatment of temporomandibular disorders (TMD). However, their precise working mechanism is unclear. This study aimed to compare the biomechanical effect of three commercially available splint designs (full covering splint, anterior bite splint and posterior bite splint) during biting in a sample of healthy subjects. Materials and methods: Magnetic resonance imaging (MRI) was combined with jaw tracking to measure the minimal intraarticular distance (MID) of 20 human temporomandibular joints (TMJ) whilst simultaneously recording the electromyogram (EMG) of the masticatory muscles. The changes caused by clenching with a bite force of 100 N without splint (baseline) and on each splint were calculated. Repeated measures ANOVA was performed on the means of the MID variations and EMG amplitudes. Results: Clenching on the anterior bite splint resulted in two times less activation of the anterior temporalis muscle than baseline (p = 0.003), full covering (p = 0.011) and posterior bite splint (p = 0.011). MID was reduced by clenching in all conditions, but the reduction was almost three times larger with the anterior bite splint compared to no splint (p = 0.011). The full covering splint and the posterior bite splint did not differ significantly in EMG activation of both masseter and temporalis muscles and MID variation. Conclusions: This study showed that splint designs have a different impact on the MID and EMG activation while clenching. The anterior bite splint had a greater impact on the reduction of the muscle activation, whereas clenching on the anterior bite splint led to bigger reduction of MID and thus had the greatest influence on alteration in the condylar position. Clinical relevance: The design of the splint can affect MID and muscle activation and is a variable to consider in the treatment of patients with TMD according to their symptoms. [ABSTRACT FROM AUTHOR]

Peripersonal space (PPS), as opposed to extrapersonal space (EPS), refers to the area surrounding the body within which individuals interact with objects or conspecifics. However, objects in PPS can belong to oneself or to others, which was found to influence how these objects are encoded. We analyzed the performances of motor responses in a reachability judgment task concerning self‐owned and other‐owned objects (cups) presented in PPS or EPS. EMG activities were recorded on the thumbs (flexor pollicis brevis) to detect correct and erroneous motor activations. Behavioral data showed that motor responses were shorter and longer for self‐owned cups compared to other‐owned cups in PPS and EPS, respectively. Ten percent of trials showed initial response errors, which were higher in the EPS for self‐owned cups and in the PPS for other‐owned cups. Eighty‐two percent of these errors were corrected online, with corrections being more efficient for self‐owned cups in the PPS. Overall, the data revealed that reachability judgments were faster and more accurate in the PPS, with more efficient inhibition processes in the presence of motor errors. Motor selection and correction are thus modulated by the social context of object ownership, highlighting the specific role of the PPS in encoding self‐relevant objects for action. We used EMG signals from thumbs to assess the influence of object ownership and location on cognitive control. Reachability judgments were provided for self‐ or other‐owned objects presented in peripersonal (PPS) or extrapersonal (EPS) space. We found higher performances in PPS for self‐owned objects and in EPS for other‐owned objects. Inhibition processes associated with ownership‐dependent motor errors were more efficient in PPS. These results highlight the psychophysiological processes underlying PPS encoding of self‐relevant objects for action. [ABSTRACT FROM AUTHOR]

Every year, many people lose their lives because of road accidents. It is evident from statistics that drowsiness is one of the main causes of a large number of car accidents. In our research, we wish to solve this major problem by measuring the drowsiness level of the human brain while driving. The study aims to develop a novel technique to detect different alertness levels (i.e., awake, moderately drowsy, and maximally drowsy) of a person while driving. A hybrid model using a stacked autoencoder and hyperbolic tangent Long Short‐Term Memory (TLSTM) network with attention mechanism is designed for this purpose. The designed model uses different biopotential signals, such as electroencephalography (EEG), facial electromyography (EMG), and different biomarkers, such as pulse rate, respiration rate galvanic skin response, and head movement to detect a person's alertness level. Here, the stacked autoencoder model is used for automated feature extraction. TLSTM is used to predict a person's alertness level using stacked autoencoder network‐extracted features. The proposed model can classify awake, moderately drowsy, and maximally drowsy states of a person with accuracies of 99%, 98.3%, and 98.6%, respectively. The novel contributions of the paper includes (i) incorporation of an attention mechanism into the TLSTM network of the proposed hybrid model to focus on the emphatic states to enhance classification accuracy, and (ii) utilization of EEG, facial EMG, pulse rate, respiration rate, galvanic skin reaction, and head movement pattern to assess a person's alertness level. [ABSTRACT FROM AUTHOR]

Background: Amyotrophic lateral sclerosis (ALS) is a lethal progressive neurodegenerative disease characterized by upper motor neuron (UMN) and lower motor neuron (LMN) involvement. Their varying degree of involvement results in a clinical heterogenous picture, making clinical assessments of UMN signs in patients with ALS often challenging. We therefore explored whether instrumented assessment using robotic manipulation could potentially be a valuable tool to study signs of UMN involvement. Methods: We examined the dynamics of the wrist joint of 15 patients with ALS and 15 healthy controls using a Wristalyzer single-axis robotic manipulator and electromyography (EMG) recordings in the flexor and extensor muscles in the forearm. Multi-sinusoidal torque perturbations were applied, during which participants were asked to either relax, comply or resist. A neuromuscular model was used to study muscle viscoelasticity, e.g. stiffness (k) and viscosity (b), and reflexive properties, such as velocity, position and force feedback gains (kv, kp and kf, respectively) that dominated the responses. We further obtained clinical signs of LMN (muscle strength) and UMN (e.g. reflexes, spasticity) dysfunction, and evaluated their relation with the estimated neuromuscular model parameters. Results: Only force feedback gains (kf) were elevated in patients (p = 0.033) compared to controls. Higher kf, as well as the resulting reflexive torque (Tref), were both associated with more severe UMN dysfunction in the examined arm (p = 0.040 and p < 0.001). Patients with UMN symptoms in the examined arm had increased kf and Tref compared to controls (both p = 0.037). Neither of these measures was related to muscle strength, but muscle stiffness (k) was lower in weaker patients (p = 0.012). All these findings were obtained from the relaxed test. No differences were observed during the instructions comply and resist. Conclusions: This findings are proof-of-concept that instrumented assessment using robotic manipulation is a feasible technique in ALS, which may provide quantitative, operator-independent measures relating to UMN symptoms. Elevated force feedback gains, driving larger reflexive muscle torques, appear to be particularly indicative of clinically established levels of UMN dysfunction in the examined arm. [ABSTRACT FROM AUTHOR]

In giant slalom, the ability to apply a high amount of force in the radial direction is essential for performance. A race is characterized by repeated turns performed at high velocity, potentially inducing fatigue. Therefore, this study aimed to assess the effect of fatigue on performance, trajectory characteristics, and force production capacities onto the snow. Twelve skiers ran a 4-turn section with (FATIGUE) and without pre-induced fatigue (CONTROL). Knee extensor maximal voluntary contraction (MVC) was performed before the experiment and after both conditions. Section time, energy dissipation, path length, total force output, force application effectiveness, and EMG activity of the main lower-limb muscles were compared between conditions. Multiple linear regressions were used to understand whether interindividual variability in the kinematic, kinetic and EMG between conditions explains variability in performance changes with fatigue. MVC was lower after FATIGUE (−19.1 ± 6.4%, p < 0.001) but did not change after CONTROL. FATIGUE was associated with longer section times (+0.21 ± 0.11 s, p < 0.001), energy dissipation (−0.78 ± 1.05 J.s.kg.m−1, p = 0.026), path length (+1.1 ± 1.6 m, p = 0.033) and lower force application effectiveness (−0.1 ± 0.1, p = 0.017). This study experimentally demonstrates that fatigue in giant slalom results in lower force application effectiveness, inducing over-dissipation of mechanical energy and longer path length, leading to lower performance. [ABSTRACT FROM AUTHOR]

AbstractPurposeMethodsResultsConclusionThe profession of physical therapy has historically relied on manual facilitation to improve motor control strategies and performance in persons rehabilitating from a stroke, yet there is insufficient evidence to support its use during functional task training. The purpose of this study was to determine the effects of integrated cueing (verbal and manual) and verbal cueing approaches during sit-to-stand training on midline alignment & muscle activation in chronic stroke survivors.Twenty-one chronic right-brained stroke survivors with hemiplegia were randomly assigned to the Integrated Cueing or Verbal Only group and outcome measures were recorded using an 18-Camera Motion Capture System, force plates, and surface electromyography (EMG).Both groups demonstrated a significant improvement in symmetry toward the midline after thirty training repetitions. Significant improvements in muscle activation were found in two muscle groups on the affected side of the body in the Integrated Cueing group, gastrocnemius and rectus femoris.Both the Verbal Only and Integrated Cueing groups made significant progress toward more symmetrical movement, yet more significant changes in the activation of hemiparetic extensor muscles were seen in the Integrated Cueing group. These findings support the use of manual cueing in movement activation and performance during the training of functional tasks.IMPLICATIONS FOR REHABPhysical therapists commonly use manual tactile cues to facilitate movement performance but there is currently insufficient evidence to support this use with stroke survivors.In a relatively small sample size, both verbal cues and integrated cues (verbal plus manual) improved symmetry during sit to stand in chronic right brain stroke survivors.Integrated cueing enhanced motor activation and performance during sit to stand better than verbal cues alone.Manual tactile cueing should be considered during functional task retraining.Physical therapists commonly use manual tactile cues to facilitate movement performance but there is currently insufficient evidence to support this use with stroke survivors.In a relatively small sample size, both verbal cues and integrated cues (verbal plus manual) improved symmetry during sit to stand in chronic right brain stroke survivors.Integrated cueing enhanced motor activation and performance during sit to stand better than verbal cues alone.Manual tactile cueing should be considered during functional task retraining. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the lower-limb muscle synergies of young and older adults during stationary cycling across various mechanical conditions to reveal adaptive strategies employed by the elderly to address various common pedaling tasks and function degradation. By comparing lower-limb muscle synergies during stationary cycling between young and old people, this study examined changes in muscle synergy patterns during exercise in older individuals. This is crucial for understanding neuromuscular degeneration and changes in movement patterns in older individuals. Sixteen young and sixteen older experienced cyclists were recruited to perform stationary cycling tasks at two levels of power (60 and 100 W) and three cadences (40, 60, and 90 rpm) in random order. The lower-limb muscle synergies and their inter- and intra-individual variability were analyzed. Three synergies were extracted in this study under all riding conditions in both groups while satisfying overall variance accounted for (VAF) > 85% and muscle VAF > 75%. The older adults exhibited lower variability in synergy vector two and a higher trend in the variability of activation coefficient three, as determined by calculating the variance ratio. Further analyses of muscle synergy structures revealed increased weighting in major contribution muscles, the forward-shifting peak activation in synergy one, and lower peak magnitude in synergy three among older adults. To produce the same cycling power and cadence as younger individuals, older adults make adaptive adjustments in muscle control—increased weighting in major contribution muscles, greater consistency in the use of primary force-producing synergies, and earlier peak activation of subsequent synergy. [ABSTRACT FROM AUTHOR]

Exoskeleton robots have the potential to augment human motor capabilities. however, current control strategies often require task-specific control laws tailored for different scenarios, which limits the applicability of exoskeletons. In this study, we propose a control strategy for exoskeleton robots that is adaptable across various scenarios. We employ adaptive oscillators (AO) with feedback control to rapidly estimate the wearer'smotion phase and subsequently provide torque assistance to the wearer's hip joint based on a TCN-LSTM model. During experiments, we collected surface electromyographic (sEMG) signals from the tibialis anterior, gastrocnemius, and rectus muscles of seven groups of subjects performing treadmill walking and inclined treadmill exercises. We utilized the short-time Fourier transform to extract frequency characteristics of the signals and statistically analyzed the rate of frequency change in each muscle group under different strategies. The results indicate that when wearing the exoskeleton, the overall muscle frequency changes more slowly, suggesting that subjects can maintain activity for a longer duration before fatigue sets in. This control strategy effectively reduces the energetic cost of lower limb work for the wearer and enhances the exoskeleton's versatility in various applications. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study investigated the behavior of postural adjustments throughout the entire action: from the preparatory phase (anticipatory postural adjustment, APA), the focal movement phase (online postural adjustments, OPA), to the compensatory phase (compensatory postural adjustment, CPA) while raising the arms in a standing position, both with eyes opened and closed. The goal was to analyze the effects of reduced sensorial information and different heights on postural muscle activity during these three phases. Methods: Eight young women performed rapid shoulder flexion while standing on the ground and on a 1-m elevated platform. The EMG activity of the trunk and lower limb muscles was recorded during all three phases. Results: Although average muscle activity was similar on the ground and the elevated platform, the pattern of postural muscle activation varied across the motor action. During OPA, all postural muscle activity was the highest, while it was the lowest during APA. On the elevated platform postural muscles have increased their activation during APA. In the most stable condition (standing on the ground with eyes opened), muscle activity showed a negative correlation between APA and OPA, but there was no correlation between OPA and CPA. Conclusions: Our results suggest postural control adapts to sensory, motor, and cognitive conditions. Therefore, the increased demand for postural control due to the height of the support base demands greater flexibility in postural synergies and alters muscle activity. [ABSTRACT FROM AUTHOR]

Kinematics, kinetics and biomechanics of human gait are widely investigated fields of research. The biomechanics of locomotion have been described as characterizing muscle activations and synergistic control, i.e., spatial and temporal patterns of coordinated muscle groups and joints. Both kinematic synergies and muscle synergies have been extracted from locomotion data, showing that in healthy people four–five synergies underlie human locomotion; such synergies are, in general, robust across subjects and might be altered by pathological gait, depending on the severity of the impairment. In this work, for the first time, we apply the mixed matrix factorization algorithm to the locomotion data of 15 healthy participants to extract hybrid kinematic–muscle synergies and show that they allow us to directly link task space variables (i.e., kinematics) to the neural structure of muscle synergies. We show that kinematic–muscle synergies can describe the biomechanics of motion to a better extent than muscle synergies or kinematic synergies alone. Moreover, this study shows that at a functional level, modular control of the lower limb during locomotion is based on an increased number of functional synergies with respect to standard muscle synergies and accounts for different biomechanical roles that each synergy may have within the movement. Kinematic–muscular synergies may have impact in future work for a deeper understanding of modular control and neuro-motor recovery in the medical and rehabilitation fields, as they associate neural and task space variables in the same factorization. Applications include the evaluation of post-stroke, Parkinson's disease and cerebral palsy patients, and for the design and development of robotic devices and exoskeletons during walking. [ABSTRACT FROM AUTHOR]

Neck pain associated with helmet‐wear is an occupational health problem often observed in helicopter pilots and aircrew. Whether aircrew helmet wearing is associated with physiological and biomechanical differences between sexes is currently unknown. This study investigated neuromuscular activation patterns during different helmet‐wearing conditions. The helmet load was manipulated through a novel Helmet Balancing System (HBS) in healthy, non‐pilot male and female participants (n = 10 each, age 19–45 years) in two phases. Phase A assessed the acute effects of helmet‐wear on neck muscles activation during head movements. Phase B examined changes in muscle activity and cervical disc height after wearing a helmet for 45 min. In Phase A, muscle activity was similar between sexes in many movements, but it was higher in female participants when wearing a helmet than in males. The HBS reduced muscle activity in both sexes. In Phase B, female participants exhibited a greater level of muscular fatigue, and male participants' cervical disc height was significantly decreased [5.7 (1.4) vs. 4.4 (1.5) mm, P < 0.001] after continuous wearing. Both sexes showed no significant change in muscle fatigue and disc height [male: 5.0 (1.3) vs. 5.2 (1.4) mm, P = 0.604] after applying HBS. These findings demonstrate sex‐specific physiological and biomechanical responses to wearing a helmet. They may indicate different postural and motor control strategies, associated with different neck pain aetiologies in male and female aircrew, the knowledge of which is important to reduce or prevent musculoskeletal injuries associated with helmet wearing. What is the central question of this study?Do sex differences exist in the neck physiological response to helmet‐wearing?What is the main finding and its importance?Sex differences exist in both the acute response and after 45 min of helmet wearing: during a given head movement, female participants' muscle activity was greater than male participants' and females also demonstrated greater muscular fatigue after continuous helmet‐wear than males while cervical disc height showed a significant reduction after 45 min helmet‐wear in males only. These findings could provide insight into future training or injury prevention strategy for pilots. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of an 8 week targeted training program on speed, agility, and muscle asymmetries in soccer players. 32 elite soccer players were recruited for the study. Their age, body mass, and body height were 25.8 ± 7.3 years, 77.4 ± 11.1 kg, and 177.5 ± 9.8 cm, respectively. After the warm-up, participants performed two maximum 30 m sprints with a 5-minute rest interval between trials. After the linear sprint test, performed two repetitions of the COD randomized ZigZag test. The tests were performed at the beginning and at the end of the pre-season, which lasted for 8 weeks. EMG was measured bilaterally from the quadriceps, hamstrings, and gluteal muscles with shorts made of knitted fabric similar to elastic clothes. Athletes in the experimental group performed sport-specific targeted strength training based on movement patterns 4 times per week (Monday, Tuesday, Thursday, and Friday). The training included 6 bodyweight exercises (Bird Dog, Single-Leg Glute Bridge, Dead Bug, Side Plank, Reverse Lunge, and Clamshell), performed unilaterally in 5 sets of 10 repetitions of each exercise. The load progression included an additional set in each successive week of the experiment. The data analysis showed significant improvement in 5 m and 30 m sprints after applying the 8-week targeted training protocol. A statistically significant improvement in performance was also observed after the 8-week training period in case of COD, while the speed deficit also decreased significantly. The greatest improvements were observed during the COD test. As a result of repeated COD training over a period of 8 weeks, its technique was improved. Implementation of training methods, which target specific aspects of soccer in the pre-season training routines can improve key motor abilities for that sports discipline. A comprehensive training approach including speed, agility, and resistance training based on specific movement patterns should be applied by strength and conditioning practitioners in soccer teams to achieve peak physical performance and reduce injury risk due to the partial elimination of muscular asymmetries. [ABSTRACT FROM AUTHOR]

Reverse shoulder arthroplasty (RSA) aims to restore function in patients with rotator cuff failure and joint arthropathy. After surgery, patients are routinely referred to a rehabilitation specialist to regain range of motion, strength, and function. A key element in these programs is active exercises. The exercises are often selected based on assumed muscle activity, investigated by electromyography (EMG). In particular, in this patient population, activation of the deltoid and the scapular muscles is the focus of exercise therapy. Currently, most studies investigating muscle activity levels during exercises are performed on healthy individuals. To our knowledge, no study exists analyzing EMG activity during exercises in a population of shoulder arthroplasty patients. Therefore, the study aimed to analyze activity in the shoulder girdle muscles during 6 commonly used rehabilitation exercises 12 weeks after reverse shoulder arthroplasty surgery. Forty-four patients (50 shoulders) participated in this cross-sectional study, 12 weeks postoperatively (mean 99.18 ± 12.8 days), aged 68.9 ± 7.75 years. Surface EMG activity was measured in 10 shoulder girdle muscles: the 3 trapezius parts, serratus anterior, the 3 deltoid parts, latissimus dorsi, and 2 pectoralis major parts during 6 exercises, 3 in a closed chain, and 3 open chain elevation exercises. Gravity-minimized exercises (horizontal plane) show low activity for almost all muscles. Vertical closed kinetic chain exercises show an increased activity compared to horizontal plane exercises. Open kinetic chain exercises against gravity showed the greatest activity in deltoid and upper trapezius. For the other muscles, no consistency in progression was found. This study offers a progression of exercises for patients after reverse shoulder arthroplasty based on increased muscle activity. [ABSTRACT FROM AUTHOR]

Rowing is a complex sport where technique can significantly impact performance. A better understanding of the rowers' technique and neuromuscular activations during scull rowing, along with their impact on rowing performance, could greatly help trainers and athletes. Twelve male rowers were asked to row at their competitive stroke rate, and we collected data describing neuromuscular activations, trunk and arm kinematics, as well as technical determinants such as oar angles and angle asymmetries. We fitted linear mixed-effect models to investigate the effects of these variables on power production and boat speed. A larger effective angle had the greatest positive effect on power output, and slip angles had the largest negative effects. Increased elbow flexion at catch had the greatest negative effect on speed. Angle asymmetries affected neither power nor speed. Increased upper limb neuromuscular activity during the first and third quarters of the drive phase helped reduce slip angles, thus increasing performance. Power and speed were influenced similarly by the predictor variables. Still, they showed subtle differences, indicating that the strategies to maximize power production might not be the best ones to also achieve the maximum speed. [ABSTRACT FROM AUTHOR]

Purpose: Neuromuscular monitoring is frequently plagued by artefacts, which along with the frequent unawareness of the principles of this subtype of monitoring by many clinicians, tends to lead to a cynical attitute by clinicians towards these monitors. As such, the present study aims to derive a feature set and evaluate its discriminative performance for the purpose of Train-of-Four Ratio (TOF-R) outlier analysis during continuous intraoperative EMG-based neuromuscular monitoring. Methods: Patient data was sourced from two devices: (1) Datex-Ohmeda Electromyography (EMG) E-NMT: a dataset derived from a prospective observational trial including 136 patients (21,891 TOF-R observations), further subdivided in two based on the type of features included; and (2) TetraGraph: a clinical case repository dataset of 388 patients (97,838 TOF-R observations). The two datasets were combined to create a synthetic set, which included shared features across the two. This process led to the training of four distinct models. Results: The models showed an adequate bias/variance balance, suggesting no overfitting or underfitting. Models 1 and 2 consistently outperformed the others, with the former achieving an F1 score of 0.41 (0.31, 0.50) and an average precision score (95% CI) of 0.48 (0.35, 0.60). A random forest model analysis indicated that engineered TOF-R features were proportionally more influential in model performance than basic features. Conclusions: Engineered TOF-R trend features and the resulting Cost-Sensitive Logistic Regression (CSLR) models provide useful insights and serve as a potential first step towards the automated removal of outliers for neuromuscular monitoring devices. Trial registration: NCT04518761 (clinicaltrials.gov), registered on 19 August 2020. Key points: • Neuromuscular monitoring is still suboptimally employed by anesthesiologists despite recent recommendations. • Artefactual phenomena are frequently reported as a cause of distrust in neuromuscular monitoring. • Machine-learning models based on universal neuromuscular monitoring variables can be developed to minimise artefacts and so increase end-user compliance. [ABSTRACT FROM AUTHOR]

The superior colliculus (SC) has been increasingly implicated in the rapid processing of evolutionarily relevant stimuli like faces, but the behavioural relevance of such processing is unclear. The SC has also been implicated in the generation of express visuomotor responses (EVR), which are very short‐latency (~80 ms) bursts of muscle activity time‐locked to visual target presentation. These observations led us to investigate the influence of faces on EVRs. We recorded upper limb muscle activity from healthy participants as they reached toward targets in the presence of a distractor. In some experiments, faces were used as stimuli. Across blocks of trials, we varied the instruction as to which stimulus served as the target or distractor. Doing so allowed us to assess the impact of instruction on muscle recruitment given identical visual stimuli. We found that responses were uniquely modulated in tasks involving high‐contrast faces, promoting reaches toward or away from a face depending on instruction. Follow‐up experiments confirmed that the phenomenon required highly salient repeated faces and was not observed to non‐facial stimuli nor to faces expressing different affects. This study extends the hypothesis that the SC mediates the EVR by demonstrating that faces impact muscle recruitment at short latencies that precede cortical activity for face perception. Our results constitute direct evidence for the behavioural relevance of face detection in the brainstem, and also implicate a role for top‐down cortical pre‐setting of the EVR depending on task context. [ABSTRACT FROM AUTHOR]

Background: The quantification of electromyographic activity using surface electrodes is invaluable for understanding gait disorders in patients with central nervous system lesions. We propose to evaluate a commercially available low-cost system compared to a reference system in participants with stroke-related movement disorders in functional situations. Methods: Three hemiparetic participants performed three functional tasks: two treadmill walks at different speeds and a sit-to-stand test. The vastus lateralis and gastrocnemius medialis muscles were equipped with two EMG sensors. The comparison between the two EMG systems was based on 883 identified cycles. Spearman's correlation coefficients (SCs), linear correlation coefficients (LCCs), and cross-correlation coefficients (CCCs) were calculated. Results: The main results indicate good to very good similarity of the EMG signals collected from the two tested sEMG systems. In the comfortable-walking condition, an SC of 0.894 ± 0.091 and an LCC of 0.909 ± 0.094 were noted. In the fast-walking condition, an SC of 0.918 ± 0.064 and an LCC of 0.935 ± 0.056 were observed. For the 1 min sit-to-stand test, an SC of 0.880 ± 0.058 and an LCC of 0.881 ± 0.065 were noted. Conclusions: This study demonstrates good to very good similarity between the two sEMG systems, enabling the analysis of muscle activity during functional tasks. [ABSTRACT FROM AUTHOR]

Activities and falls monitoring systems using wearable technology have a promising future. The publicly available datasets are based on a few inertial features only acquired with an accelerometer, gyroscope, smartphone or smart Watches. The activities and falls performed are also less. In this study, a dataset is created by collecting physiological features along with inertial features which will help in developing and validating systems studying the effect of physiological features on the detection and prediction of falls and activities. The dataset consists of 7 activities and 8 falls for inertial data; 2 activities for ECG data; 6 activities for EMG data and 6 activities for GSR data. Basic body parameters like height, weight, etc. along with beats per minute, SpO2 and blood pressure are also recorded for 12 subjects. The collected data is analyzed statistically using a boxplot, pair plot, correlation heatmap and p value. The activities are classified using SVM, KNN, RF and DT. For GSR, more than 90% accuracy is achieved and for EMG, the accuracy is less than 80%. For IMU data, more than 95% accuracy is achieved. The results encourage combining inertial, physiological and basic body parameters to detect and predict falls and activities. [ABSTRACT FROM AUTHOR]

Background: Sarcopenia is a muscle disorder causing a progressive reduction of muscle mass and strength, but the mechanism of its manifestation is still partially unknown. The three main parameters to assess are: muscle strength, muscle volume or quality and low physical performance. There is not a definitive approach to assess the musculoskeletal condition of frail population and often the available tests to be performed in those clinical bedridden patients is reduced because of physical impairments. In this paper, we propose a novel instrumental multi-domain and non-invasive approach during a well-defined protocol of measurements for overcoming these limitations. A group of 28 bedridden elder people, subjected to surgery after hip fracture, was asked to perform voluntary isometric contractions at the 80% of their maximum voluntary contraction with the non-injured leg. The sensor employed before and/or during the exercise were: ultrasound to determine the muscle architecture (vastus lateralis); force acquisition with a load cell placed on the chair, giving an indication of the muscle strength; surface electromyography (EMG) for monitoring muscular electrical activity; time-domain (TD) near-infrared spectroscopy (NIRS) for evaluating muscle oxidative metabolism. Results: A personalized "report card" for each subject was created. It includes: the force diagram (both instantaneous and cumulative, expected and measured); the EMG–force diagram for a comparison between EMG derived median frequency and measured force; two graphs related to the hemodynamic parameters for muscle oxidative metabolism evaluation, i.e., oxy-, deoxy-, total-hemoglobin and tissue oxygen saturation for the whole exercise period. A table with the absolute values of the previous hemodynamic parameters during the rest and the ultrasound related parameters are also included. Conclusions: In this work, we present the union of protocols, multi-domain sensors and parameters for the evaluation of the musculoskeletal condition. The novelties are the use of sensors of different nature, i.e., force, electrical and optical, together with a new way to visualize and combine the results, by means of a concise, exhaustive and personalized medical report card for each patient. This assessment, totally non-invasive, is focused on a bedridden population, but can be extended to the monitoring of rehabilitation progresses or of the training of athletes. [ABSTRACT FROM AUTHOR]

Dynamic muscle fatigue during repetitive movements can lead to changes in communication between the central nervous system and peripheral muscles. This study investigated these changes by examining electromyogram (EMG) characteristics from agonist and antagonist muscles during a fatiguing task. Twenty-two healthy male university students (age: 22.92 ± 2.19 years) performed heel raises until fatigue. EMG signals from lateral gastrocnemius (GL) and tibialis anterior (TA) muscles were processed using synchrosqueezed wavelet transform (SST). Root mean square (RMS), mean frequency (MF), power across frequency ranges, wavelet coherence, and co-activation ratio were computed. During the initial 80% of the task, RMS and EMG power increased for both muscles, while MF declined. In the final 20%, GL parameters stabilized, but TA showed significant decreases. Beta and gamma intermuscular coherence increased upon reaching 60% of the task. Alpha coherence and co-activation ratio remained constant. Results suggest that the central nervous system adopts a differentiated control strategy for agonist and antagonist muscles during fatigue progression. Initially, a coordinated "common drive" mechanism enhances both muscle groups' activity. Later, despite continued increases in muscle activity, neural-muscular coupling remains stable. This asynchronous, differentiated control mechanism enhances our understanding of neuromuscular adaptations during fatigue, potentially contributing to the development of more targeted fatigue assessment and management strategies. [ABSTRACT FROM AUTHOR]

The diaphragm muscle (DIAm) is the primary inspiratory muscle in mammals. In awake animals, considerable heterogeneity in the electromyographic (EMG) activity of the DIAm reflects varied ventilatory and nonventilatory behaviors. Experiments in awake animals are an essential component to understanding the neuromotor control of breathing, which has especially begun to be appreciated within the last decade. However, insofar as the intent is to study the control of breathing, it is paramount to identify DIAm EMG activity that in fact reflects breathing. Current strategies for doing so in a reproducible, reliable, and efficient fashion are lacking. In the present article, we evaluated DIAm EMG from awake animals using hierarchical clustering across four-dimensional feature space to classify eupneic breathing. Our model, which can be implemented with automated threshold of the clustering dendrogram, successfully identified eupneic breathing with high F1 score (0.92), specificity (0.70), and accuracy (0.88), suggesting that it is a robust and reliable tool for investigating the neural control of breathing. NEW & NOTEWORTHY: The heterogeneity of diaphragm muscle (DIAm) activity in awake animals reflects real motor behavior diversity but makes assessments of eupneic breathing challenging. The present article uses an unsupervised machine learning model to identify eupneic breathing amidst a deluge of different DIAm electromyography (EMG) burst patterns in awake rats. This technique offers a scalable and reliable tool that improves efficiency of DIAm EMG analysis and minimizes potential sources of bias. [ABSTRACT FROM AUTHOR]

Gait phase recognition systems based on surface electromyographic signals (EMGs) are crucial for developing advanced myoelectric control schemes that enhance the interaction between humans and lower limb assistive devices. However, machine learning models used in this context, such as Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM), typically experience performance degradation when modeling the gait cycle with more than just stance and swing phases. This study introduces a generalized phasor-based feature extraction approach (PHASOR) that captures spatial myoelectric features to improve the performance of LDA and SVM in gait phase recognition. A publicly available dataset of 40 subjects was used to evaluate PHASOR against state-of-the-art feature sets in a five-phase gait recognition problem. Additionally, fully data-driven deep learning architectures, such as Rocket and Mini-Rocket, were included for comparison. The separability index (SI) and mean semi-principal axis (MSA) analyses showed mean SI and MSA metrics of 7.7 and 0.5, respectively, indicating the proposed approach's ability to effectively decode gait phases through EMG activity. The SVM classifier demonstrated the highest accuracy of 82% using a five-fold leave-one-trial-out testing approach, outperforming Rocket and Mini-Rocket. This study confirms that in gait phase recognition based on EMG signals, novel and efficient muscle synergy information feature extraction schemes, such as PHASOR, can compete with deep learning approaches that require greater processing time for feature extraction and classification. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this paper, a comprehensive exploration is undertaken to elucidate the utilization of Spiking Neural Networks (SNNs) within the biomedical domain. The investigation delves into the experimentally validated advantages of SNNs in comparison to alternative models like LSTM, while also critically examining the inherent limitations of SNN classifiers or algorithms. SNNs exhibit distinctive advantages that render them particularly apt for targeted applications within the biomedical field. Over time, SNNs have undergone extensive scrutiny in realms such as neuromorphic processing, Brain-Computer Interfaces (BCIs), and Disease Diagnosis. Notably, SNNs demonstrate a remarkable affinity for the processing and analysis of biomedical signals, including but not limited to electroencephalogram (EEG), electromyography (EMG), and electrocardiogram (ECG) data. This paper initiates its exploration by introducing some of the biomedical applications of EMG, such as the classification of hand gestures and motion decoding. Subsequently, the focus extends to the applications of SNNs in the analysis of EEG and ECG signals. Moreover, the paper delves into the diverse applications of SNNs in specific anatomical regions, such as the eyes and noses. In the final sections, the paper culminates with a comprehensive analysis of the field, offering insights into the advantages, disadvantages, challenges, and opportunities introduced by various SNN models in the realm of healthcare and biomedical domains. This holistic examination provides a nuanced perspective on the potential transformative impact of SNN across a spectrum of applications within the biomedical landscape. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) has had a significant impact on human life because of its pervasiveness across industries and its rapid development. Although AI has achieved superior performance in learning and reasoning, it encounters challenges such as substantial computational demands, privacy concerns, communication delays, and high energy consumption associated with cloud-based models. These limitations have facilitated a paradigm change in on-device AI processing, which offers enhanced privacy, reduced latency, and improved power efficiency through the direct execution of computations on devices. With advancements in neuromorphic systems, spiking neural networks (SNNs), often referred to as the next generation of AI, are currently in focus as on-device AI. These technologies aim to mimic the human brain efficiency and provide promising real-time processing with minimal energy. This study reviewed the application of SNNs in the analysis of biomedical signals (electroencephalograms, electrocardiograms, and electromyograms), and consequently, investigated the distinctive attributes and prospective future paths of SNNs models in the field of biomedical signal analysis. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the effectiveness of a passive back-support exosuit at reducing low back muscle fatigue during an 18-minute trunk posture maintenance task. On two separate days sixteen participants performed an 18-minute trunk posture profile that reflected trunk flexion postures observed during a challenging vascular surgery procedure. On one day they performed the procedure with the support of the exosuit, on the other day without. Test contractions were performed every three minutes to capture the time-dependent electromyographic activity of the bilateral erector spinae muscles. Time domain (amplitude) and frequency domain (median frequency) measures of erector spinae muscle fatigue were assessed. Results revealed that the exosuit significantly reduced the measures of erector spinae muscle fatigue in terms of both amplitude (6.1%) and median frequency (5.3%), demonstrating a fatigue reduction benefit of the exosuit in a realistic surgical posture maintenance task. PRACTITIONER SUMMARY: To examine the potential adoption of a back-support exosuit system in the surgical environment, this study used an 18-minute posture maintenance task that reflected trunk flexion postures observed during a vascular surgery procedure and suggests that the exosuit system can effectively reduce low back muscle fatigue during a vascular surgical procedure. [ABSTRACT FROM AUTHOR]

Abstract Background Amyotrophic lateral sclerosis (ALS) is a lethal progressive neurodegenerative disease characterized by upper motor neuron (UMN) and lower motor neuron (LMN) involvement. Their varying degree of involvement results in a clinical heterogenous picture, making clinical assessments of UMN signs in patients with ALS often challenging. We therefore explored whether instrumented assessment using robotic manipulation could potentially be a valuable tool to study signs of UMN involvement. Methods We examined the dynamics of the wrist joint of 15 patients with ALS and 15 healthy controls using a Wristalyzer single-axis robotic manipulator and electromyography (EMG) recordings in the flexor and extensor muscles in the forearm. Multi-sinusoidal torque perturbations were applied, during which participants were asked to either relax, comply or resist. A neuromuscular model was used to study muscle viscoelasticity, e.g. stiffness (k) and viscosity (b), and reflexive properties, such as velocity, position and force feedback gains (kv, kp and kf, respectively) that dominated the responses. We further obtained clinical signs of LMN (muscle strength) and UMN (e.g. reflexes, spasticity) dysfunction, and evaluated their relation with the estimated neuromuscular model parameters. Results Only force feedback gains (kf) were elevated in patients (p = 0.033) compared to controls. Higher kf, as well as the resulting reflexive torque (Tref), were both associated with more severe UMN dysfunction in the examined arm (p = 0.040 and p

Abstract Neck pain associated with helmet‐wear is an occupational health problem often observed in helicopter pilots and aircrew. Whether aircrew helmet wearing is associated with physiological and biomechanical differences between sexes is currently unknown. This study investigated neuromuscular activation patterns during different helmet‐wearing conditions. The helmet load was manipulated through a novel Helmet Balancing System (HBS) in healthy, non‐pilot male and female participants (n = 10 each, age 19–45 years) in two phases. Phase A assessed the acute effects of helmet‐wear on neck muscles activation during head movements. Phase B examined changes in muscle activity and cervical disc height after wearing a helmet for 45 min. In Phase A, muscle activity was similar between sexes in many movements, but it was higher in female participants when wearing a helmet than in males. The HBS reduced muscle activity in both sexes. In Phase B, female participants exhibited a greater level of muscular fatigue, and male participants’ cervical disc height was significantly decreased [5.7 (1.4) vs. 4.4 (1.5) mm, P

Abstract Background Sarcopenia is a muscle disorder causing a progressive reduction of muscle mass and strength, but the mechanism of its manifestation is still partially unknown. The three main parameters to assess are: muscle strength, muscle volume or quality and low physical performance. There is not a definitive approach to assess the musculoskeletal condition of frail population and often the available tests to be performed in those clinical bedridden patients is reduced because of physical impairments. In this paper, we propose a novel instrumental multi-domain and non-invasive approach during a well-defined protocol of measurements for overcoming these limitations. A group of 28 bedridden elder people, subjected to surgery after hip fracture, was asked to perform voluntary isometric contractions at the 80% of their maximum voluntary contraction with the non-injured leg. The sensor employed before and/or during the exercise were: ultrasound to determine the muscle architecture (vastus lateralis); force acquisition with a load cell placed on the chair, giving an indication of the muscle strength; surface electromyography (EMG) for monitoring muscular electrical activity; time-domain (TD) near-infrared spectroscopy (NIRS) for evaluating muscle oxidative metabolism. Results A personalized “report card” for each subject was created. It includes: the force diagram (both instantaneous and cumulative, expected and measured); the EMG–force diagram for a comparison between EMG derived median frequency and measured force; two graphs related to the hemodynamic parameters for muscle oxidative metabolism evaluation, i.e., oxy-, deoxy-, total-hemoglobin and tissue oxygen saturation for the whole exercise period. A table with the absolute values of the previous hemodynamic parameters during the rest and the ultrasound related parameters are also included. Conclusions In this work, we present the union of protocols, multi-domain sensors and parameters for the evaluation of the musculoskeletal condition. The novelties are the use of sensors of different nature, i.e., force, electrical and optical, together with a new way to visualize and combine the results, by means of a concise, exhaustive and personalized medical report card for each patient. This assessment, totally non-invasive, is focused on a bedridden population, but can be extended to the monitoring of rehabilitation progresses or of the training of athletes.

The passive stay apparatus works by blocking flexion of the knee and tarsus joints in the horse, preventing muscle fatigue. During ambulation, if this mechanism fails to release, the animal will present upward fixation of the patella, which in severe cases, can only be treated by medial patellar desmotomy (MPD). The objective of this study was to investigate the possible electromyographic and behavioral changes, after the impairment of the passive stay apparatus, in horses who have undergone MPD surgery. Five horses presenting dorsal fixation of the patella underwent electromyographic measurements at preoperatively and immediately postoperatively, 24 h, seven, 14 and 21 days after surgery. The samples were collected on a computerized surface electromyograph designed in accordance with the standards of international society of electrophysiology and kinesiology (ISEK). To capture the signals, electrodes positioned on the tensor fasciae lata, vastus lateralis, biceps femoris and semitendinosus muscles were used, bilaterally. These muscles were chosen due to their participation in the passive stay apparatus. The electromyographic signals were collected and processed using a software calibrated to collect data with a sampling frequency of 1000 Hz per channel. The collections took place over 60 min periods, and the results were obtained from the root means square (RMS) analysis. It was noted that the preoperative average of rest in tripedal support was 62%. On the other hand, change in weight bearing member and rest in three limbs in the postoperative period did not occur. This inability to maintain tripedal support in the postoperative period prevents the horse from resting while standing. Furthermore, there was a gradual increase in the need for post-surgical muscle recruitment, resulting in long periods of decubitus due to muscle fatigue, which is less than ideal for such large animals. Therefore, it was concluded that the animals submitted to medial patellar desmotomy, in this study, presented an inability to maintain tripedal support, in addition to a greater need for recruitment of muscle fibers, evidenced by the gradual increase in the electromyographic tracing and total RMS value of the muscles evaluated. [ABSTRACT FROM AUTHOR]

This paper presents Part 2 of a study that investigated the effects of an 8-week (3x/week) underwater treadmill (UT) walking intervention on knee osteoarthritis (KOA) outcomes in 6 adults with KOA (62.7 ± 14.2 years). The Knee Outcome Survey (KOS) for activities of daily living and muscle activity during a 10-m walk and a 20 cm step down were measured before and after the intervention. The following KOS measures improved after the UT walking program (p < 0.05; g > 0.8): stiffness, swelling, weakness, walking, going up stairs, going downstairs, kneeling on the front of the knee, squatting, and sitting with the knee bent. Knee flexion excursion during stance of walking increased after the UT walking intervention (p = .01). Co-activation between the tibialis anterior and medial gastrocnemius decreased during the 20 cm step down (p = .04). The findings of this study support using the WWE as a model for UT walking interventions in KOA. [ABSTRACT FROM AUTHOR]

Abstract Background The elbow is a common site for overuse injuries in golfers. Tendinopathies, such as medial and lateral epicondylitis, are frequently diagnosed in amateur and professional golfers. The aim of our study was to determine the effect of an ergonomic golf grip on forearm muscle activity during the five phases of the golf swing. Methods Thirty right-handed golfers with a mean age of 32 years (range, 18–70 years) and a mean handicap of 15 (range, 0–43) performed 10 golf swings with a standard and ergonomic golf grip respectively. The mean and maximum muscle activity of the Musculus (M.) extensor carpi radialis brevis (ECRB), M. flexor carpi ulnaris (FCU), M. pronator teres (PT) and M. biceps brachii (BB) of the lead and trail arms were assessed during the five phases of the golf swing using surface electromyography (EMG). Subgroup analyses were performed regarding sex, playing ability (handicap 20 h) and preexisting elbow pain during golfing (VAS

Purpose: People with both pronated feet and anterior cruciate ligament repair may benefit from walking on sand as a therapeutic option. The consequences of walking on sand on the muscular activity and gait biomechanics of these people are not well understood. This study aims to determine how sand training affects gait mechanics in individuals with both anterior cruciate ligament repair and pronated foot. Methods: The intervention and control groups included 28 adult males with pronated feet, where anterior cruciate ligament repair was randomly performed. The walking task was done on an 18-meter walkway at a consistent velocity. Muscle activities and ground reaction forces (GRF) were recorded using an electromyography system and a Bertec force plate, respectively. Results: Group-by-time interactions were significant for anterior and posterior reaction forces (P

Electromyography (EMG), galvanic skin responses (GSR), and electrocardiogram (ECG) tools have been used to investigate emotional responses to marketing stimuli, encompassing advertisements, product packaging, and brand logos. However, despite the widespread application of EMG, GSR, and ECG tools in neuromarketing research, a comprehensive synthesis of their collective impact remains conspicuously absent. Addressing this gap is the primary goal of the present review paper, which systematically scrutinizes recent studies employing EMG, GSR, and ECG to assess emotional responses to marketing stimuli. Employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, relevant articles were meticulously extracted from the Scopus database, spanning the years 2009 to 2022, including twenty articles for detailed analysis. The outcomes of this review underscore the unique insights offered by these tools into emotional reactions, emphasizing that their collective utilization can afford a more comprehensive understanding of these intricate processes. This propels advancements in comprehending the pivotal role of emotions in consumer behavior and serves as a guidepost for future research directions in this burgeoning field. Ultimately, this paper aims to furnish a broad understanding and detailed insights into the current trends within neuromarketing research, specifically employing EMG, GSR, and ECG tools.

Introduction. Clinical and instrumental predictors of the efficiency of conservative and surgical treatment of median nerve neuropathy in the carpal tunnel still remain a topical issue. Aim. To identify clinical and instrumental predictors of clinical outcomes and patients’ satisfaction after conservative and surgical treatment of carpal tunnel syndrome. Materials and methods. Analysis of clinical outcomes and patients’ satisfaction in 93 cases with carpal tunnel syndrome: the first group included 49 patients (68 wrists) after conservative and the second group included 44 patients (50 wrists) after surgical treatment. To identify predictors of the efficiency of treatment, analyzed the following clinical-instrumental values: patients’ age, duration of the disease, discriminative sensation, pain intensity according to VAS, values of DASH, BCTQ, CTS scales, clinical stage by Hi-Ob scale, electromyography severity grade according to Bland J.D., nerve conduction study and sonography results. Results. The nerve conduction study and clinical examinations data (discriminative sensation, clinical stage, duration of the disease, BCTQ and DASH values) show reliable effects on clinical outcomes and patients’ satisfaction after conservative treatment. The sensory nerve action potential amplitude and electromyography severity grade have the highest prognostic accuracy (91.4% and 84.5% respectively) for poor (unsatisfactory) result. For surgical treatment, identified results of nerve conduction study, sonography, and patients' age show reliable effects on clinical outcomes and patients’ satisfaction. The values of the highest prognostic accuracy for poor (unsatisfactory) result were nerve deformity index established by sonography (77.8%) and thenar compound muscle action potential amplitude – by nerve conduction study (78.7%). Conclusions. We identified clinical-instrumental predictors of clinical outcomes and patients’ satisfaction after conservative and surgical treatment of carpal tunnel syndrome. Specific results of instrumental examination demonstrated excellent diagnostic quality and the highest prognostic accuracy.

Background: The elbow is a common site for overuse injuries in golfers. Tendinopathies, such as medial and lateral epicondylitis, are frequently diagnosed in amateur and professional golfers. The aim of our study was to determine the effect of an ergonomic golf grip on forearm muscle activity during the five phases of the golf swing. Methods: Thirty right-handed golfers with a mean age of 32 years (range, 18–70 years) and a mean handicap of 15 (range, 0–43) performed 10 golf swings with a standard and ergonomic golf grip respectively. The mean and maximum muscle activity of the Musculus (M.) extensor carpi radialis brevis (ECRB), M. flexor carpi ulnaris (FCU), M. pronator teres (PT) and M. biceps brachii (BB) of the lead and trail arms were assessed during the five phases of the golf swing using surface electromyography (EMG). Subgroup analyses were performed regarding sex, playing ability (handicap < 10 vs. ≥10), weekly playing time (≤ 5 h, 5–20 h, > 20 h) and preexisting elbow pain during golfing (VAS < 2 vs. VAS ≥ 2). Significance was set at p < 0.05. Results: An ergonomic golf grip resulted in a reduction in muscle activity in at least one but up to three consecutive phases of the golf swing for the ECRB, FCU and PT of the lead arm and for the PT of the trail arm. Amateurs, a playing time < 20 h per week and golfers without preexisting elbow pain were factors that were associated with greater reductions in muscle activity. Conclusion: Forearm muscle activity can be decreased using an ergonomic golf grip, indicating the possible role of an ergonomic golf grip as a preventive measure against overuse syndromes such as medial and lateral epicondylitis. Trial registration number: This study was retrospectively registered at the German Clinical Trials Register DRKS-ID: DRKS00033732 (01/03/2024). [ABSTRACT FROM AUTHOR]

The objective was to investigate the effects of running shoes with midsole hollow structure span and height on the biomechanics of the lower limbs during running. We collected 21 adults with running habits who wore two pairs of running shoes with different midsole hollow structures and ran at a speed of 3.3m/s on a force-measuring treadmill. The lower limb kinematics, ground reaction force (GRF) and lower limb muscle activation characteristics were simultaneously captured by a motion capture system, a 3D force treadmill, and a surface electromyography (sEMG) system. Paired t-tests were performed on data for the two shoe conditions that fit the normal distribution assumptions; otherwise, Wilcoxon signed-rank tests were used. The statistical parameter mapping (SPM) technology was used for the analysis of 1D parameters of kinematic, dynamic, and sEMG activation characteristics. The result showed that the time to the peak impact force at touchdown of Hollow shoe2 was significantly increased (P<0.01), the maximum loading rate (P<0.01) and average loading rate (P<0.05) were significantly reduced, braking time (P<0.05), push time (P<0.05), contact time (P<0.01) of Hollow shoe2 were significantly increased compared with Hollow shoe1. Hollow shoe2 push phase of the tibialis anterior muscle activation characteristics was significantly lower (SPM, P<0.05) than Hollow shoe1. Our conclusion is that running shoes offer the solution as they have the advantage of the complex structure of the hollow midsole. [ABSTRACT FROM AUTHOR]

This study delves into decoding hand gestures using surface electromyography (EMG) signals collected via a precision Myo-armband sensor, leveraging machine learning algorithms. The research entails rigorous data preprocessing to extract features and labels from raw EMG data. Following partitioning into training and testing sets, four traditional machine learning models are scrutinized for their efficacy in classifying finger movements across seven distinct gestures. The analysis includes meticulous parameter optimization and five-fold cross-validation to evaluate model performance. Among the models assessed, the Random Forest emerges as the top performer, consistently delivering superior precision, recall, and F1-score values across gesture classes, with ROC-AUC scores surpassing 99%. These findings underscore the Random Forest model as the optimal classifier for our EMG dataset, promising significant advancements in healthcare rehabilitation engineering and enhancing human–computer interaction technologies. [ABSTRACT FROM AUTHOR]

After stroke, the poorer recovery of motor function of upper extremities compared to other body parts is a longstanding problem. Based on our recent functional MRI evidence on healthy volunteers, this perspective paper proposes systematic hand motor rehabilitation utilizing the plasticity of interhemispheric interaction between motor cortices and following its developmental rule. We first discuss the effectiveness of proprioceptive intervention on the paralyzed (immobile) hand synchronized with voluntary movement of the intact hand to induce muscle activity in the paretic hand. In healthy participants, we show that this bilateral proprioceptive-motor coupling intervention activates the bilateral motor cortices (= bilaterally active mode), facilitates interhemispheric motorcortical functional connectivity, and augments muscle activity of the passivelymoved hand. Next, we propose training both hands to perform different movements, which would be effective for stroke patients who becomes able to manage to move the paretic hand. This bilaterally different movement training may guide the motor cortices into left-right independent mode to improve interhemispheric inhibition and hand dexterity, because we have shown in healthy older adults that this training reactivates motor-cortical interhemispheric inhibition (= left-right independent mode) declined with age, and can improve hand dexterity. Transition of both motor cortices from the bilaterally active mode to the left-right independent mode is a developmental rule of hand motor function and a common feature of motor function recovery after stroke. Hence, incorporating the brain's inherent capacity for spontaneous recovery and adhering to developmental principles may be crucial considerations in designing effective rehabilitation strategies. [ABSTRACT FROM AUTHOR]

The objective of the article is to recognize users' emotions by classifying facial electromyographic (EMG) signals. A biomedical signal amplifier, equipped with eight active electrodes positioned in accordance with the Facial Action Coding System, was used to record the EMG signals. These signals were registered during a procedure where users acted out various emotions: joy, sadness, surprise, disgust, anger, fear, and neutral. Recordings were made for 16 users. The mean power of the EMG signals formed the feature set. We utilized these features to train and evaluate various classifiers. In the subject-dependent model, the average classification accuracies were 96.3% for KNN, 94.9% for SVM with a linear kernel, 94.6% for SVM with a cubic kernel, and 93.8% for LDA. In the subject-independent model, the classification results varied depending on the tested user, ranging from 91.4% to 48.6% for the KNN classifier, with an average accuracy of 67.5%. The SVM with a cubic kernel performed slightly worse, achieving an average accuracy of 59.1%, followed by the SVM with a linear kernel at 53.9%, and the LDA classifier at 41.2%. Additionally, the study identified the most effective electrodes for distinguishing between pairs of emotions. [ABSTRACT FROM AUTHOR]

Muscle synergies are defined as coordinated recruitment of groups of muscles with specific activation balances and time profiles aimed at generating task-specific motor commands. While muscle synergies in postural control have been investigated primarily in reactive balance conditions, the neuromechanical contribution of muscle synergies during voluntary control of upright standing is still unclear. In this study, muscle synergies were investigated during the generation of isometric force at the trunk during the maintenance of standing posture. Participants were asked to maintain the steady-state upright standing posture while pulling forces of different magnitudes were applied at the level at the waist in eight horizontal directions. Muscle synergies were extracted by nonnegative matrix factorization from sixteen lower limb and trunk muscles. An average of 5-6 muscle synergies were sufficient to account for a wide variety of EMG waveforms associated with changes in the magnitude and direction of pulling forces. A cluster analysis partitioned the muscle synergies of the participants into a large group of clusters according to their similarity, indicating the use of a subjective combination of muscles to generate a multidirectional force vector in standing. Furthermore, we found a participant-specific distribution in the values of cosine directional tuning parameters of synergy amplitude coefficients, suggesting the existence of individual neuromechanical strategies to stabilize the whole-body posture. Our findings provide a starting point for the development of novel diagnostic tools to assess muscle coordination in postural control and lay the foundation for potential applications of muscle synergies in rehabilitation. [ABSTRACT FROM AUTHOR]

How the neuromechanics of the lower limb functional muscle groups change with running speed remains to be fully elucidated, with implications for our understanding of human locomotion, conditioning, and injury prevention. This study compared the neuromechanics (ground reaction and joint kinetics, kinematics and muscle activity) of middle‐distance athletes running on an instrumented treadmill at six wide‐ranging speeds (2.78–8.33 m·s−1). Ground reaction forces and kinematics were analyzed using inverse dynamics to calculate flexor and extensor joint torques, and positive and negative work done by these torques. Contributions of each functional muscle group to the total positive and negative work done by the limb during stance, swing, and the whole stride were quantified. During stance, the ankle plantar flexors were the major energy generator and absorber (>60%) at all speeds, but their contribution to whole stride energy generation and absorption declined with speed. Positive work by the hip extensors rose superlinearly with speed during stance (3‐fold) and especially during swing (12‐fold), becoming the biggest energy generator across the whole stride at >5 m·s−1. Knee flexor and extensor negative work also rose superlinearly with speed during swing, with the knee flexors becoming the greatest energy absorber over the whole stride at >7.22 m·s−1. Across speeds, plantar flexor peak moment and positive work accounted for 97% and 96% of the variance in step length, and swing hip extension peak moment and positive work accounted for 98% and 99% of the variance in step frequency. There were pronounced speed, phase (stance/swing), and work (positive/negative) dependent contributions of the different functional muscle groups during running, with extensive implications for conditioning and injury prevention. [ABSTRACT FROM AUTHOR]

Functional electrical stimulation (FES) is a rehabilitation and assistive technique used for stroke survivors. FES systems mainly consist of sensors, a control algorithm, and a stimulation unit. However, there is a critical need to reassess sensing and control techniques in FES systems to enhance their efficiency. This SLR was carried out following the PRISMA 2020 statement. Four databases (PubMed, Scopus, Web of Science, Wiley Online Library) from 2010 to 2024 were searched using terms related to sensing and control strategies in FES systems. A total of 322 articles were chosen in the first stage, while only 60 of them remained after the final filtering stage. This systematic review mainly focused on sensor techniques and control strategies to deliver FES. The most commonly used sensors reported were inertial measurement units (IMUs), 45% (27); biopotential electrodes, 36.7% (22); vision-based systems, 18.3% (11); and switches, 18.3% (11). The control strategy most reported is closed-loop; however, most of the current commercial FES systems employ open-loop strategies due to their simplicity. Three main factors were identified that should be considered when choosing a sensor for gait-oriented FES systems: wearability, accuracy, and affordability. We believe that the combination of computer vision systems with artificial intelligence-based control algorithms can contribute to the development of minimally invasive and personalized FES systems for the gait rehabilitation of patients with FDS. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease, characterized by loss of central and peripheral motor neurons. Although the disease is clinically and genetically heterogeneous, axonal hyperexcitability is a commonly observed feature that has been suggested to reflect an early pathophysiological step linked to the neurodegenerative cascade. Therefore, it is important to clarify the mechanisms causing axonal hyperexcitability and how these relate to the clinical characteristics of patients. Measures derived directly from a nerve excitability recording are frequently used as study end points, although their biophysical basis is difficult to deduce. Mathematical models can aid in the interpretation but are reliable only when applied to group-averaged recordings. Consequently, model estimates of membrane properties cannot be compared with clinical characteristics or treatment effects in individual patients, posing a considerable limitation in heterogeneous diseases, such as amyotrophic lateral sclerosis. To address these challenges, we revisited nerve excitability using a new pattern analysis-based approach (principal component analysis). We evaluated disease-specific patterns of excitability changes and established their biophysical origins. Based on the observed patterns, we developed new compound measures of excitability that facilitate the implementation of this approach in clinical settings. We found that excitability changes in amyotrophic lateral sclerosis patients (n = 161, median disease duration = 11 months) were characterized by four unique patterns compared with controls (n = 50, age and sex matched). These four patterns were best explained by changes in resting membrane potential (modulated by Na+/K+ currents), slow potassium and sodium currents (modulated by their gating kinetics) and refractory properties of the nerve. Consequently, we were able to show that altered gating of slow potassium channels was associated with, and predictive of, the rate of progression of the disease on the amyotrophic lateral sclerosis functional rating scale. Based on these findings, we designed four composite measures that capture these properties to facilitate implementation outside this study. Our findings demonstrate that changes in nerve excitability in patients with amyotrophic lateral sclerosis are dominated by four distinct patterns, each with a distinct biophysical origin. Based on this new approach, we provide evidence that altered slow potassium-channel function might play a role in the rate of disease progression. The magnitudes of these patterns, quantified using a similar approach or our new composite measures, have potential as efficient measures to study membrane properties directly in amyotrophic lateral sclerosis patients, and thus aid prognostic stratification and trial design. [ABSTRACT FROM AUTHOR]

Introduction/Aims: Paired‐pulse stimulation provides clinically useful information regarding sensory inhibition. When supraorbital nerve stimulation is repeated within a short interval, the response to the second stimulation is reduced to varying degrees. This magnitude of change in stimulation response can be monitored by electromyogram (EMG) or by mechanomyogram (MMG) as in this report. MMG has some advantages such as being less time consuming and lacking stimulus artifact. We compared the use of MMG and EMG to validate MMG as an effective method of assessing blink reflex paired‐pulse inhibition. Methods: Eight volunteers participated. Participants received electrical stimulation to the supraorbital nerve of each side. A paired‐pulse paradigm was employed, varying the conditioning‐test interval between 5 and 800 ms. The R1 component of the induced blink reflex was simultaneously recorded by EMG using a pair of electrodes placed on the lower eyelid and by MMG using an accelerometer placed between the electrodes. Results: The correlation coefficient of the R1 amplitude between MMG and EMG of the grand‐averaged waveforms was 0.99. The average participant r value was.91 (range.76–.99). Similar analyses were performed for the amplitude variation of the second response relative to the first response. Results correlated well, yielding r values of.97 and.86 for the grand‐averaged waveform and the average for each subject. Discussion: The present results demonstrate that MMG could be an alternative to EMG in assessing paired‐pulse inhibition of the electrical blink reflex R1 component. [ABSTRACT FROM AUTHOR]