Characteristics of EMG frequency bands in temporomandibullar disorders patients

Superelastic Radiative Cooling Metafabric for Comfortable Epidermal Electrophysiological Monitoring

Epidermal electronics with superb passive-cooling capabilities are of great value for both daytime outdoor dressing comfort and low-carbon economy. Herein, a multifunctional and skin-attachable electronic is rationally developed on a porous all-elastomer metafabric for efficient passive daytime radiative cooling (PDRC) and human electrophysiological monitoring. The cooling characteristics are realized through the homogeneous impregnation of polytetrafluoroethylene microparticles in the styrene-ethylene-butylene-styrene fibers, and the rational regulation of microporosity in SEBS/PTFE metafabrics, thus synergistically backscatter ultraviolet-visible-near-infrared light (maximum reflectance over 98.0%) to minimize heat absorption while efficiently emit human-body midinfrared radiation to the sky. As a result, the developed PDRC metafabric achieves approximately 17 °C cooling effects in an outdoor daytime environment and completely retains its passive cooling performance even under 50% stretching. Further, high-fidelity electrophysiological monitoring capability is also implemented in the breathable and skin-conformal metafabric through liquid metal printing, enabling the accurate acquisition of human electrocardiograph, surface electromyogram, and electroencephalograph signals for comfortable and lengthy health regulation. Hence, the fabricated superelastic PDRC metafabric opens a new avenue for the development of body-comfortable electronics and low-carbon wearing technologies.

Do Temporomandibular Disorder Patients with Joint Pain Exhibit Forward Head Posture? A Cephalometric Study

Purpose

To evaluate head and cervical posture in individuals with or without temporomandibular disorders (TMDs) and to assess the correlations between pain, severity of symptoms, and posture.

Methods

A total of 384 patients (129 males and 255 females) was included. The Fonseca Anamnestic Index (FAI) was used to assess the severity and prevalence of TMD and the presence of temporomandibular joint (TMJ) pain. Patients were divided into three groups: the TMD-free group, TMD without TMJ pain group, and TMD with TMJ pain group. Subsequently, the patients with TMJ pain were further divided into mild TMD and moderate/severe TMD groups. Nine parameters were traced on cephalograms to characterize the head and cervical posture.

Results

TMD patients with TMJ pain showed increased forward head posture (FHP) than patients without TMJ pain and TMD-free subjects. No significant difference was observed between the TMD patients without TMJ pain and TMD-free subjects. In the TMD patients with the TMJ pain group, the moderate/severe TMD patients demonstrated increased FHP compared to mild TMD patients. TMD patients with joint pain had greater CVT/RL (B = 3.099), OPT/RL (B = 2.117), and NSL/C2' (B = 4.646) than the patients without joint pain after adjusting for confounding variables (P < 0.05).

Conclusion

TMD patients with TMJ pain showed increased FHP compared to other groups, and FHP became more significant as TMD severity increased in male patients, indicating the FHP might play an important role in the development of TMJ pain. In the clinical assessment of TMD, the patients' abnormal head and cervical posture might be considered.

Inter-muscular networks of synchronous muscle fiber activation

Skeletal muscles continuously coordinate to facilitate a wide range of movements. Muscle fiber composition and timing of activation account for distinct muscle functions and dynamics necessary to fine tune muscle coordination and generate movements. Here we address the fundamental question of how distinct muscle fiber types dynamically synchronize and integrate as a network across muscles with different functions. We uncover that physiological states are characterized by unique inter-muscular network of muscle fiber cross-frequency interactions with hierarchical organization of distinct sub-networks and modules, and a stratification profile of links strength specific for each state. We establish how this network reorganizes with transition from rest to exercise and fatigue-a complex process where network modules follow distinct phase-space trajectories reflecting their functional role in movements and adaptation to fatigue. This opens a new area of research, Network Physiology of Exercise, leading to novel network-based biomarkers of health, fitness and clinical conditions.

Evaluation of Pelvic Floor Muscles in Pregnancy and Postpartum With Non-Invasive Magnetomyography

Objective: To record and characterize features of levator ani muscles (LAM) activity in pregnancy and postpartum using non-invasive and novel Magnetomyography (MMG) technique with amplitude and spectral parameters. Methods: Nulliparous women with uncomplicated pregnancies participated in the MMG data collection during rest and voluntary LAM contractions (Kegels) with modulated intensity in third trimester and approximately 2 months postpartum (PP). Simultaneous surface electromyography was recorded to document the recruitment of accessory muscles. Moderate strength Kegel (MK) MMG trials were analyzed. Amplitude and spectral parameters including root-mean square (RMS) amplitude, power spectrum density (PSD) and normalized PSD (rPSD) in three frequency bands (low, middle, high) were computed on MK epochs. Statistical comparisons between pregnancy and postpartum were calculated. Results: MMG recordings were measured from 10 pregnant women. Results showed decreased RMS and power between third trimester and postpartum, trending towards significance. rPSD values in the low frequency band decreased significantly (p = 0.028) from third trimester to postpartum, while significant increase was observed in the middle frequency band (p = 0.018). Conclusions: This study shows that MMG as non-invasive tool has the ability to detect and characterize changes of LAM activity with amplitude and spectral parameters during pregnancy and postpartum.

Parallel-Inception CNN Approach for Facial sEMG based Silent Speech Recognition

With the purpose of providing an external human-machine interaction platform for the elderly in need, a novel facial surface electromyography based silent speech recognition system was developed. In this study, we propose a deep learning architecture named Parallel-Inception Convolutional Neural Network (PICNN), and employ up-to-date feature extraction method log Mel frequency spectral coefficients (MFSC). To better meet the requirements of our target users, a 100-class dataset containing daily life-related demands was designed and generated for the comparative experiments. According to experimental results, the highest recognition accuracy of 88.44% was achieved by proposed recognition framework based on MFSC and PICNN, exceeding the performance of state-of-the-art deep learning algorithms such as CNN, VGGNet and Inception CNN (3.22%, 4.09% and 1.19%, respectively). These findings suggest that the newly developed silent speech approach holds promise to provide a more reliable communication channel, and the application scenery of speech recognition technology has been expanded at the same time.

Is jaw muscle activity impaired in adults with persistent temporomandibular disorders? A systematic review and meta-analysis

Understanding jaw muscle activity changes in temporomandibular disorders (TMD) is crucial to guide clinical management. The nature of these changes is currently unclear. Explore changes in jaw muscle activity in TMD. Electronic databases (PubMed, EMBASE, CINAHL, Scopus, Web of Science, Cochrane) and bibliographies were searched from inception to 9 July 2020 for eligible studies, including grey literature. Case-control and interventional studies reporting time-domain and frequency-domain electromyographic measures of jaw muscle activity in TMD and control groups were included. SIGN checklist for case-control studies was used to evaluate risk of bias. Results were pooled for meta-analysis using random-effects model. Confidence in cumulative evidence was established using American Academy of Neurology guidelines. Forty-five studies were included. Most were rated moderate risk of bias. Activity of four muscles (masseter, temporalis, lateral pterygoid, suprahyoids) was assessed across six domains (resting, clenching, chewing, swallowing, concentrating, resisted mandibular movements), with partial meta-analysis scope. Masseter and temporalis activity were significantly higher at rest (P = .05, P < .0001), but lower during brief maximal clenching (P = .005, P = .04) in TMD vs controls. Insufficient data precluded meta-analysis of remaining outcomes and subgroup analysis. Confidence in cumulative evidence ranged from moderate to very low. Changes in jaw muscle activity exist in TMD, which are both task-specific and muscle-specific. It remains unclear whether jaw muscle activity changes vary between TMD subgroups. Muscle function should be considered in clinical management of TMD. Insufficient subgroup data highlight future direction for research.

Functional evaluation of triceps surae during heel rise test: from EMG frequency analysis to machine learning approach

Soleus muscle flap as coverage tissue is a possible surgical solution adopted to cover the wounds due to open fractures. Despite this procedure presents many clinical advantages, relatively poor information is available about the loss of functionality of triceps surae of the treated leg. In this study, a group of patients who underwent a soleus muscle flap surgical procedure has been analyzed through the heel rise test (HRT), in order to explore the triceps surae residual functionalities. A frequency band analysis was performed in order to assess whether the residual heads of triceps surae exhibit different characteristics with respect to both the non-treated lower limb and an age-matched control group. Then, an in-depth analysis based on a machine learning approach was proposed for discriminating between groups by generalizing across new unseen subjects. Experimental results showed the reliability of the proposed analyses for discriminating between-group at a specific time epoch and the high interpretability of the proposed machine learning algorithm allowed the temporal localization of the most discriminative frequency bands. Findings of this study highlighted that significant differences can be recognized in the myoelectric spectral characteristics between the treated and contralateral leg in patients who underwent soleus flap surgery. These experimental results may support the clinical decision-making for assessing triceps surae performance and for supporting the choice of treatment in plastic and reconstructive surgery. Graphical Abstract The Graphical abstract presents the scope of the proposed analysis of myoelectric signals of soleus and gastrocnemius muscles of patiens groups during Hell Rise Test, highlighting the applied methods and the obtained results.

Comparison of the pattern of activation of the masticatory muscles among individuals with and without TMD: A systematic review

OBJECTIVE

To verify the characteristics of the electromyographic signal of masticatory muscles in individuals with TMD and asymptomatic individuals.

METHODS

A systematic review was carried out, selecting cross-sectional studies with at least one electromyographic parameter (FM; iEMG; RMS) of the masticatory muscles (anterior temporal, bilateral masseter, and suprahyoid muscles) of individuals with TMD compared to asymptomatic individuals.

RESULTS

This review identified 1656 titles, of which 30 articles were included in the final analysis. It was observed that the data referring to the pattern of activation of masticatory muscles in the rest, isometry, and isotonic conditions of individuals with TMD are heterogeneous. This fact may be related to variability in the methods and analyses applied in the studies.

CONCLUSION

Data referring to the pattern of activation of masticatory muscles in the rest and isometry conditions and in the mastication cycle of individuals with TMD and asymptomatic individuals are diverse.

Acupuncture in Temporomandibular Disorders Painful Symptomatology: An Evidence-Based Case Report

Temporomandibular dysfunction (TMD) is complex and multifactorial. Its etiology involves various factors, such as malocclusion, psychological patterns, parafunctional habits, and the temporomandibular joint anatomy. Symptoms include myofascial pain, joint clicking, mouth opening limitation, headaches, earaches, and neck pain, comprising one of the greatest causes of nondental pain. Acupuncture has been used to treat these conditions by acting locally both in muscle relaxation and pain management as well as reaching physical, mental, and emotional balance. The aim of this study is to present a brief literature review reporting the efficacy of acupuncture on TMDs and a case report in which the painful symptomatology of TMD was treated with a systemic protocol, based on scientific evidence and concepts of traditional Chinese medicine. Acupuncture may be a complementary treatment for TMD, and in this case report, it eliminated the patient's painful symptomatology.

Intra-Day and Inter-Day Reliability of Measurements of the electromyographic signal on masseter and temporal muscles in patients with Down syndrome

The aim of the present study was to evaluate intra-day (test) and inter-day (re-test) reliability of surface electromyography (sEMG) signals of the masseter and temporal muscles in patients with Down syndrome (DS). We determined the reliability of sEMG variables in 33 patients with DS. EMG signals were recorded at rest as well as during maximum voluntary clenching and maximum habitual intercuspation (MHI). The signals were analyzed considering the amplitude in the root mean square (RMS), mean frequency (MNF), median frequency (MDF) and approximate entropy (ApEn). The intraclass correlation (ICC_2,1) for the three trials recorded during MHI in the two sessions (test and retest) revealed excellent intra-session and inter-session reliability (ICC_2,1 = 0.76 to 0.97) for all sEMG variables and muscles. In the rest position, excellent reliability was found for RMS and ApEn (ICC_2,1 = 0.75 to 1.00) and good to excellent reliability was found for MDF and MNF (ICC_2,1 = 0.64 to 0.93). The intra-session (test) and inter-session (re-test) analyses demonstrated the reliability of nonlinear sEMG variables of the masticatory muscles in adults with Down Syndrome.

Electromyography of the masticatory muscles during chewing in different head and neck postures - A pilot study

Objectives

The objectives of this pilot study were to analyze the electromyography (EMG) activity of masseter and anterior temporalis muscles during chewing in 2 different posture conditions: natural head posture (NHP) and maximum yet comfortable forward head posture (FHP) in healthy individuals; and to compare EMG activity between subjects based on their NHP during chewing.

Methods

Fifteen subjects participated. Sagittal head posture in sitting position was clinically assessed using a plumb line. Participants were classified as having FHP or upright head posture (UP). Surface EMG was used to evaluate superficial masseter and anterior temporalis bilaterally during chewing in NHP and FHP. Three trials with five chewing cycles were recorded. EMG data were normalized using a maximum voluntary contraction. An independent t-test was used to calculate differences between sides. If no differences were found, both sides were analyzed together. To analyze differences between the 2 conditions, a paired t-test was used. Independent t-test was used to calculate difference between subjects with UP and FHP.

Results

A significant increase in muscle activity was found for masseter muscle in the FHP condition. No differences were found in muscle activity in natural head position by posture classification. A trend of increased activity was observed for masseter and temporalis muscles during chewing in FHP.

Conclusion

Head and neck posture was found to influence masticatory muscle activity during the function of chewing. The results of this study may help clinicians to better understand the association between head and neck posture alterations with masticatory muscles related disorders.

Evaluation of the masticatory muscle function, physiological sleep variables, and salivary parameters after electromechanical therapeutic approaches in adult patients with Down syndrome: a randomized controlled clinical trial

Background

There are many comorbidities associated with Down syndrome (DS), including obstructive sleep apnea (OSA) and masticatory muscle alteration. Muscular hypotonia, in particular, of the masticatory and oropharyngeal muscles is one of the main characteristics of individuals with DS, resulting in impairments of speech, swallowing, and mastication in these individuals. In addition, total or partial obstruction of the airways during sleep can occur due to pharyngeal hypotonia, leading to snoring and to OSA. This progressive respiratory disorder is associated with a high risk of morbidity and mortality in individuals with DS. The aim of this research is to assess the therapeutic effects of surface neuromuscular electrical stimulation (NMES), the mastication apparatus (MA), and a mandibular advancement oral appliance (OA_m) with an embedded thermosensitive microchip on the functions of masticatory muscles (bilateral masseter and temporal muscles), physiological sleep variables, and salivary parameters in adult patients with DS.

Methods

The patients with DS will be randomly selected and divided into three groups (DS-NMES, DS-MA, and DS-OA_m) with a minimum of 10 patients in each group. A thermosensitive microchip will be embedded in the OA_m to record its compliance. The therapeutic effects on masticatory muscle function will be investigated through electromyography, a caliper, and a force-transducer device; the sleep variables, in turn, will be evaluated by means of polysomnography. The physicochemical and microbiological properties of the saliva will also be analyzed, including the salivary flow, viscosity, buffer capacity, cortisol levels (susceptibility to psychological and/or physical stress), and Pseudomonas aeruginosa levels (risk of aspiration pneumonia) in these patients. The methods determined for this study will be carried out prior to and after 2 months of the recommended therapies.

Discussion

The primary outcomes would be the improvement and/or reestablishment of the function of masticatory muscles and the physiological sleep variables in this target public since individuals with DS commonly present generalized muscular hypotonia and dysfunction of the oropharyngeal musculature. As a secondary outcome indicator, the impact of the applied therapies (NMES, MA, and OA_m) on the salivary microbiological and physicochemical properties in DS individuals will also be assessed. Furthermore, the compliance of OA_m usage will be measured through a thermosensitive microchip.

Trial registration

Registro Brasileiro de Ensaios Clínicos, RBR-3qp5np. Registered on 20 February 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3300-0) contains supplementary material, which is available to authorized users.

Characterizing pelvic floor muscles activities using magnetomyography

AIMS

To characterize levator ani muscle (LAM) activity in nulligravidas using magnetomyography (MMG) and define MMG characteristics associated with LAM activity with and without accessory muscle contributions.

METHODS

MMG data were collected from eight nulligravidas during rest and voluntary LAM contractions (Kegels) of varying intensity. We utilized simultaneous vaginal manometry and surface electromyography (sEMG) to evaluate for accessory muscle recruitment. Moderate Kegel (MK) MMG trials were sub-selected based on the presence or absence of accessory muscle interaction. Amplitude and spectral-related indicators were calculated across MK epochs: root-mean square (RMS) amplitude, percentage amplitude relative to rest, and relative power spectrum density (rPSD) in three frequency bands (low, middle, high). Ternary diagram characterized rPSD from selected Kegels and ROC analysis was performed to identify cut-points to differentiate MKs from interacting MKs.

RESULTS

Nineteen MMG recordings were obtained. Amplitude and spectral parameters were significantly different between isolated and interacting MK epochs. Mean RMS and power values of the isolated MK were, respectively, 120.66 ± 43.8 fT and 1.72 ± 1.44 (T² /Hz)*10^-28 . Amplitudes of MK were 64% and 117 higher than baseline activities for the isolated and interacting epochs, respectively. ROC curves reveled cut-off points on low and middle frequency bands that achieved perfect separation (ROC-AUC = 1.0) between isolated and interacting MK.

CONCLUSIONS

Our study demonstrates that MMG, a novel biomagnetic technique, allows precise detection and characterization of normal female pelvic floor function. Results show that isolated moderate voluntary contraction of the LAMs produces distinct MMG amplitude and spectral characteristics compared with Kegels involving co-activation of other muscle groups.

Experimental and Numerical Characterization of the Mechanical Masseter Muscle Response During Biting

Predictive simulations of the mastication system would significantly improve our understanding of temporomandibular joint (TMJ) disorders and the planning of cranio-maxillofacial surgery procedures. Respective computational models must be validated by experimental data from in vivo characterization of the mastication system's mechanical response. The present pilot-study demonstrates the feasibility of a combined experimental and numerical procedure to validate a computer model of the masseter muscle. An experimental setup is proposed that provides a simultaneous bite force measurement and ultrasound-based visualization of muscle deformation. The direct comparison of the experimentally observed and numerically predicted muscle response demonstrates the predictive capabilities of such anatomically accurate biting models. Differences between molar and incisor biting are investigated; muscle deformation is recorded for three different bite forces in order to capture the effect of increasing muscle fiber recruitment. The three-dimensional (3D) muscle deformation at each bite position and force-level is approximatively reconstructed from ultrasound measurements in five distinct cross-sectional areas (four horizontal and one vertical cross section). The experimental work is accompanied by numerical simulations to validate the predictive capabilities of a constitutive muscle model previously formulated. An anatomy-based, fully 3D model of the masseter muscle is created from magnetic resonance images (MRI) of the same subject. The direct comparison of experimental and numerical results revealed good agreement for maximum bite forces and masseter deformations in both biting positions. The present work therefore presents a feasible in vivo measurement system to validate numerically predicted masseter muscle contractions during mastication.

Photobiomodulation improves motor response in patients with spinal cord injury submitted to electromyographic evaluation: randomized clinical trial

Photobiomodulation is a treatment that has been widely used in neurotrauma and neurodegenerative diseases. In the present study, low-level laser therapy was administered to patients with spinal cord injury. Twenty-five individuals were divided into two groups: placebo photobiomodulation plus physiotherapy and active photobiomodulation plus physiotherapy. Electromyographic evaluations were performed before and after 12 sessions of phototherapy as well as 30 days after the end of treatment. In the active phototherapy group, median frequency values of the brachial biceps and femoral quadriceps muscles were higher at rest and during isotonic contraction 30 days after photobiomodulation (p = 0.0258). No significant results were found regarding the rest and isotonic conditions in the pre-photobiomodulation period (p = 0.950) or immediately following photobiomodulation (p = 0.262). The data provide evidence that phototherapy improves motor responses in individuals with spinal cord injury, as demonstrated by differences in the EMG signal before and after treatment.

TRIAL REGISTRATION

NCT 03031223.