sEMG Analysis

The aim of the study was to analyze the relationship between stress measured by the perceived stress scale (PSS-10) questionnaire and masticatory muscle activity. Experimental design assumed the study of healthy young women without temporomandibular disorders, dividing them into three groups depending on the result of the stress level and then comparing these groups in terms of bioelectrical activity of the masticatory muscles. After the exclusion criteria were applied, 63 female students (mean age: 22.3 ± 2.4 years) from Medical University of Lublin were included in the study. The subjects were then divided into 3 groups: with low (n = 18), medium (n = 18) and high stress level (n = 27), according to PSS-10 results. Resting and functional activity of temporalis anterior (TA) and masseter (MM) muscles were measured by electromyograph BioEMG III. There were statistically significant effects of group on the absolute value of asymmetry index (AsI) of TA and MM during maximum voluntary ...

Masticatory muscle activity during teeth clenching is associated with changes in many physiological parameters throughout the body. Clenching can improve muscle activity, force production, rate of force development, and joint fixation. Hence, teeth clenching and masticatory muscle activity can be important in competitive sports activities. Sport climbing is becoming increasingly popular and will be included for the first time in the Summer Olympic Games, Tokyo, 2020. However, masticatory muscle activity in sport climbers has not yet been studied. The aim of the presented study is to compare the bioelectrical activity of the masticatory muscles in sport climbers and non-climbers in order to determine the relationship between these muscles and climbing activity. 44 subjects without masticatory system disorders (16 women and 28 men, average age 26.3) were divided into two groups of 22 sport climbers (8 women, 14 men, climbing experience >4 years), while 22 people (8 women, 14 men, w...

We propose and evaluate a new method for measuring and discriminating among flexion, extension, abduction and adduction movements of hand fingers. In particular, flex sensors allowed registering flexion-extension movements, whereas data from multi-channel surface electromyography (sEMG) electrodes allowed discriminating adduction-abduction movements of thumb, index and middle fingers. An electronic interface was designed to acquire and pre-process signals feeding a Personal Computer (PC), running indigenously made routines for data recording, visualization and storing. A novel test for repeatability and reproducibility was also proposed and successfully adopted.

Introduction. Characteristics of pain complaints of
patients have changed. Currently, more and more patients
report pain in the temporomandibular joint (TMJ) area
that result from excessive tension of the muscles in the
masticatory system. They need complex treatment
including trigger point release therapy that is one of the
leading methods used in case of excessive muscle tension.
Aim. Assessment of the efficacy of trigger point therapy
of the ascending part of the trapezius muscle with
superficial electromyography (sEMG) in patients reporting
pain in the temporomandibular joint area.
Material and methods. The study included 20 male patients aged between 21 and 26 years (the mean age of 22.6) reporting
complaints associated with pain and dysfunction of the
masticatory system. Patients had an assessment of pain
performed with the VAS scale before and after treatment.
In the study group electromyography measurements of
the trapezius muscle in the isometric position lasting for
30 seconds were performed with the Myon Motion Capture
before and after trigger point release therapy. Results.
The level of pain measured with the VAS scale reduced
after treatment. The reduction of the sEMG signal in the
isometric position after treatment was lower than before
treatment.
Conclusions. The application of trigger point
release therapy on the trapezius muscle contributes to
slower reduction of the sEMG signal frequency during
isometric contraction what may indicate that this muscle
works more efficiently during contraction. Trigger point
release therapy performed once helps reduce pain
complaints reported by patients in their temporomandibular
joints. The superficial electromyography objectively
indicates that trigger point release therapy of the trapezius
muscle demonstrating excessive tension in its ascending
part is effective.

This study aimed to assess the relationship between the occurrence of cervical myofascial pain with active myofascial trigger points (MTrPs) within the upper trapezius muscle and the electromyographic asymmetry index (AsI) of masticatory muscles: temporalis anterior (TA), superficial part of the masseter muscle (MM), and anterior belly of the digastric muscle (DA). The study group comprised 100 subjects (80 women and 20 men) aged 18 to 30 years (mean 23 ± 2.6 years) reporting pain in the neck muscles, diagnosed with myofascial pain with active MTrPs only within the upper trapezius muscle. The control group comprised 60 healthy, pain-free subjects (42 women and 18 men) aged 20 to 30 years (mean 22.8 ± 2.6 years) without MTrPs in the upper trapezius muscle. The palpation measurement, based on the diagnostic criteria of Travell and Simons, was used to diagnose active MTrPs. The masticatory muscle activity was recorded using an 8-channel device for surface electromyography—BioEMG IIITM....

The stomatognathic system is a functional complex of tissues and organs located within the oral and craniofacial cavities. The craniofacial anatomical factors and the biomechanics of the temporomandibular joints affect many systems throughout the body, including the organ of vision. However, few scientific reports have shown a relationship between the organ of vision and the stomatognathic system. The purpose of this review is to provide an overview of connections along neural, muscle-fascial, and biochemical pathways between the organ of vision and the stomatognathic system. Based on the literature presented in this review, the connections between the organ of vision and the stomatognathic system seem undeniable. Understanding the anatomical, physiological, and biochemical interrelationships may allow to explain the interactions between the mentioned systems. According to the current knowledge, it is not possible to indicate the main linking pathway; presumably, it may be a combination of several presented pathways. The awareness of this relationship among dentists, ophthalmologists, physiotherapists, and optometrists should increase for the better diagnosis and treatment of patients.

We propose a methodological study for the optimization of surface EMG (sEMG)-based hand gesture classification, effective to implement a human-computer interaction device for both healthy subjects and transradial amputees. The widely commonly used unsupervised Principal Component Analysis (PCA) approach was compared to the promising supervised common spatial pattern (CSP) methodology to identify the best classification strategy and the related tuning parameters. A low density array of sEMG sensors was built to record the muscular activity of the forearm and classify five different hand gestures. Twenty healthy subjects were recruited to compute optimized parameters for ("within" analysis) and to compare between ("between" analysis) the two strategies. The system was also tested on a transradial amputee subject, in order to assess the robustness of the optimization in recognizing disabled users' gestures. Results show that RMS-WA/ANN is the best feature vector/classifier pair for the PCA approach (accuracy 88.81 ± 6.58%), whereas M-RMS-WA/ANN is the best pair for the CSP methodology (accuracy of 89.35 ± 6.16%). Statistical analysis on classification results shows no significant differences between the two strategies. Moreover we found out that the optimization computed for healthy subjects was proven to be sufficiently robust to be used on the amputee subject. This motivates further investigation of the proposed methodology on a larger sample of amputees. Our results are useful to boost EMG-based hand gesture recognition and constitute a step toward the definition of an efficient EMG-controlled system for amputees.

We propose a methodological study for the optimization of surface EMG (sEMG)-based hand gesture classification, effective to implement a human-computer interaction device for both healthy subjects and transradial amputees. The widely commonly used unsupervised Principal Component Analysis (PCA) approach was compared to the promising supervised common spatial pattern (CSP) methodology to identify the best classification strategy and the related tuning parameters. A low density array of sEMG sensors was built to record the muscular activity of the forearm and classify five different hand gestures. Twenty healthy subjects were recruited to compute optimized parameters for ("within" analysis) and to compare between ("between" analysis) the two strategies. The system was also tested on a transradial amputee subject, in order to assess the robustness of the optimization in recognizing disabled users' gestures. Results show that RMS-WA/ANN is the best feature vector/classifier pair for the PCA approach (accuracy 88.81 ± 6.58%), whereas M-RMS-WA/ANN is the best pair for the CSP methodology (accuracy of 89.35 ± 6.16%). Statistical analysis on classification results shows no significant differences between the two strategies. Moreover we found out that the optimization computed for healthy subjects was proven to be sufficiently robust to be used on the amputee subject. This motivates further investigation of the proposed methodology on a larger sample of amputees. Our results are useful to boost EMG-based hand gesture recognition and constitute a step toward the definition of an efficient EMG-controlled system for amputees.

There is an urgent need for a simple yet robust system to identify natural hand actions and gestures for controlling prostheses and other computer-assisted devices. Surface electromyogram (SEMG) is a non-invasive measure of the muscle activities but is not reliable because there are a multiple simultaneously active muscles. This study proposes the use of independent component analysis (ICA) for SEMG to separate activity from different muscles. A mitigation strategy to overcome shortcomings related to order and magnitude ambiguity related to ICA has been developed. This is achieved by using a combination of unmixing matrix obtained from FastICA analysis and weight matrix derived from training of the supervised neural network corresponding to the specific user. This is referred to as ICANN (independent component analysis neural network combination). Experiments were conducted and the results demonstrate a marked improvement in the accuracy. The other advantages of this system are that it is suitable for real time operations and it is easy to train by a lay user.

The aim of the study was to analyze the relationship between stress measured by the perceived stress scale (PSS-10) questionnaire and masticatory muscle activity. Experimental design assumed the study of healthy young women without temporomandibular disorders, dividing them into three groups depending on the result of the stress level and then comparing these groups in terms of bioelectrical activity of the masticatory muscles. After the exclusion criteria were applied, 63 female students (mean age: 22.3 ± 2.4 years) from Medical University of Lublin were included in the study. The subjects were then divided into 3 groups: with low (n = 18), medium (n = 18) and high stress level (n = 27), according to PSS-10 results. Resting and functional activity of temporalis anterior (TA) and masseter (MM) muscles were measured by electromyograph BioEMG III. There were statistically significant effects of group on the absolute value of asymmetry index (AsI) of TA and MM during maximum voluntary clenching on dental cotton rollers (both p = 0.02). Post hoc analysis shows that there were statistically significant differences between medium and high stress groups in AsI TA (p = 0.01) and between low and high stress groups in AsI MM (p = 0.02). Perceived stress measured by PSS-10 questionnaire seems to be associated with changes in muscular asymmetry in functional clenching activity.

Introduction: Modern literature indicates an uptrend in the occurrence of sleep disorders. Currently, about 30-40% of adults are suffering from sleep disorders, which makes them one of the most common health problems of the population. The aim of the study: The determination of the quality of sleep on the muscle tension of the masticatory apparatus. Methods and materials: 27 adults volunteered to take part in the study. After the application of the exclusion criteria, 12 women (with an average age of 23 ± 1 year) have qualified. They were subsequently divided into two equal groups, in accordance with the guidelines of the Pittsburgh questionnaire: six women with a below 6 point result - high quality of sleep and six women with an over 6 point result (or higher) - low quality of sleep. Electromyographic activity of the anterior temporalis (TA) and masseter muscle (MM) was evaluated in resting mandibular position. Based on the electromyographic results, the values of the asymmetry indexes of the muscles of the masticatory apparatus muscles were calculated. The U Mann-Whitney test has been used for the statistical analysis, with the significance level of 0,05. Results: There were no significant differences in resting activity of the anterior temporalis, masseter muscles and the asymmetry index of the anterior temporalis between groups (p>0,05). There was the significant difference in the asymmetry index of masseter muscles between groups (p<0,05). Conclusions: The quality of sleep has no significant influence on the resting activity of masticatory muscles. The influence of the quality of sleep on the asymmetry index should be the object of further research. In order to verify this conclusion, the research should be carried out on a larger group of people.

Objectives: Changes in activity of masticatory muscles can contribute to the development of temporomandibular disorders and myofascial pain syndrome of the head. Masticatory muscle pain, usually found over the temporalis and masseter muscles, is almost 2 times more frequent in women than in men. The aim of the study was to examine bioelectrical activity of the masticatory muscles among healthy young adults in relation to sex. Material and methods: Forty full dentate, normo-occlusion healthy young adults (20 men, 20 women; mean age 21 ± 2 years) were included into the study. The exclusion criteria were: the presence of signs or symptoms of temporomandibular disorders based on an RDC/TMD examination, and neurological disorders. Electromyographic activity of the anterior temporalis (TA) and masseter muscle (MM) was evaluated in three conditions: during resting mandibular position, during maximum intercuspation clenching, and maximum voluntary clenching with cotton rolls between teeth. ...

The presented study aimed to analyze and compare the electromyographic patterns of masticatory muscles in subjects with active myofascial trigger points (MTrPs) within upper trapezius, patients with temporomandibular disorders (TMDs) and healthy adults. Based on the diagnostic criteria of MTrPs according to Travell & Simons and the Research Diagnostic Criteria for Temporomandibular Disorders, 167 people were qualified for the study. Subjects were divided into 3 groups: with active MTrPs in the upper trapezius, with diagnosed temporomandibular disorders (TMDs) and healthy adults. Measurements of the bioelectric activity of the temporalis anterior (TA) and masseter muscle (MM) were carried out using the BioEMG III ™. Based on statistical analysis, significantly lower values of TA resting activity were observed among controls in comparison to MTrPs (1.49 μV vs. 2.81 μV, p = 0.00) and TMDs (1.49 μV vs. 2.97 μV, p = 0.01). The POC index values at rest differed significantly between MTrPs...

Active myofascial trigger points (MTrPs) in masticatory muscles are associated with a reduced range of motion and muscle weakness within the stomatognathic system. However, it is hard to identify the most effective treatment technique for disorders associated with MTrPs. The objective of this study was to analyze the acute effect of the compression technique (CT) on active maximal mouth opening (MMO) and electromyographic activity of the masseter (MM) and temporalis anterior (TA) muscles in subjects with active myofascial trigger points in the MM muscles. The study group comprised 26 women (mean age 22 ± 2) with bilateral active myofascial trigger points (MTrPs) in the MM. The control group comprised 26 healthy women (mean age 22 ± 1) without the presence of MTrPs in the MM. Masticatory muscle activity was recorded in two conditions (during resting mandibular position and maximum voluntary clenching) before and after the application of the CT to the MTrPs in MM. After the CT applica...

Surface Electromyography (sEMG) activity of the forearm muscle was recorded from five subjects performing isometric contraction until fatigue. The signals were recorded into three stages (Non-Fatigued, Fatigued and fully Fatigued)through which different features were extracted for analysis purposes. Subject's specific Surface Electromyography (sEMG) activity of forearm muscle was recorded after the exercise which take place for four weeks. Amplitude parameters were extracted for each of thethree classes to quantify the potential performance of each feature, that could aid in differentiating the classes(Non-Fatigued, Fatigued and Fully Fatigued) of muscle fatigue within the sEMG signal.We use thegraphical and tabular approach to show the parameters that best distinguish and quantify class separability. The purpose of the work presented is to show the change in various parameters which are extracted from recorded sEMG signal to detect the presence of fatigue in the forearm muscle.

Objectives: Changes in activity of masticatory muscles can contribute to the development of temporomandibular disorders and myofascial pain syndrome of the head. Masticatory muscle pain, usually found over the tem-poralis and masseter muscles, is almost 2 times more frequent in women than in men. The aim of the study was to examine bioelectrical activity of the masticatory muscles among healthy young adults in relation to sex. Material and methods: Forty full dentate, normo-occlusion healthy young adults (20 men, 20 women; mean age 21 ± 2 years) were included into the study. The exclusion criteria were: the presence of signs or symptoms of tem-poromandibular disorders based on an RDC/TMD examination, and neuro-logical disorders. Electromyographic activity of the anterior temporalis (TA) and masseter muscle (MM) was evaluated in three conditions: during resting mandibular position, during maximum intercuspation clenching, and maximum voluntary clenching with cotton rolls between teeth. The 8-channel electromyograph BioEMG III, compatible with BioPAK Measurement System, was used for the recording. Results: Mean resting electrical activity of the TA muscle was significantly higher (p<0,05) among women (TAR: 1,78 μV; TA-L: 1,95 μV) comparing to men (TAR: 1,05 μV; TA-L: 1,30 μV). The differences between the two groups in relation to the mean bioelectrical activity of the MM muscles during resting mandibular position, and TA and MM muscles during maximum intercuspation clenching and maximum voluntary clenching with cotton rolls between teeth, were not statistically significant (p>0,05).
Conclusions: The resting activity of anterior temporalis muscles is higher in women, which may be a predictor of pain and TMD within this group.

There is an urgent need for a simple yet robust system to identify natural hand actions and gestures for controlling prostheses and other computer-assisted devices. Surface electromyogram (SEMG) is a non-invasive measure of the muscle activities but is not reliable because there are a multiple simultaneously active muscles. This study proposes the use of independent component analysis (ICA) for SEMG to separate activity from different muscles. A mitigation strategy to overcome shortcomings related to order and magnitude ambiguity related to ICA has been developed. This is achieved by using a combination of unmixing matrix obtained from FastICA analysis and weight matrix derived from training of the supervised neural network corresponding to the specific user. This is referred to as ICANN (independent component analysis neural network combination). Experiments were conducted and the results demonstrate a marked improvement in the accuracy. The other advantages of this system are that it is suitable for real time operations and it is easy to train by a lay user.

We propose a methodological study for the optimization of surface EMG (sEMG)-based hand gesture classification, effective to implement a human-computer interaction device for both healthy subjects and transradial amputees. The widely commonly used unsupervised Principal Component Analysis (PCA) approach was compared to the promising supervised Common Spatial Pattern (CSP) methodology to identify the best classification strategy and the related tuning parameters. A low density array of sEMG sensors was built to record the muscular activity of the forearm and classify five different hand gestures. Twenty healthy subjects were recruited to compute optimized parameters for (“within” analysis) and to compare between (“between” analysis) the two strategies. The system was also tested on a transradial amputee subject, in order to assess the robustness of the optimization in recognizing disabled users’ gestures. Results show that RMS-WA/ANN is the best feature vector/classifier pair for the...

Masticatory muscle activity during teeth clenching is associated with changes in many physiological parameters throughout the body. Clenching can improve muscle activity, force production, rate of force development, and joint fixation. Hence, teeth clenching and masticatory muscle activity can be important in competitive sports activities. Sport climbing is becoming increasingly popular and will be included for the first time in the Summer Olympic Games, Tokyo, 2020. However, masticatory muscle activity in sport climbers has not yet been studied. The aim of the presented study is to compare the bioelectrical activity of the masticatory muscles in sport climbers and non-climbers in order to determine the relationship between these muscles and climbing activity. 44 subjects without masticatory system disorders (16 women and 28 men, average age 26.3) were divided into two groups of 22 sport climbers (8 women, 14 men, climbing experience &gt;4 years), while 22 people (8 women, 14 men, w...

There is an urgent need for a simple yet robust system to identify natural hand actions and gestures for
controlling prostheses and other computer-assisted devices. Surface electromyogram (SEMG) is a non-invasive
measure of the muscle activities but is not reliable because there are a multiple simultaneously active
muscles. This study proposes the use of independent component analysis (ICA) for SEMG to separate activity
from different muscles. A mitigation strategy to overcome shortcomings related to order and magnitude
ambiguity related to ICA has been developed. This is achieved by using a combination of unmixing matrix
obtained from FastICA analysis and weight matrix derived from training of the supervised neural network
corresponding to the specific user. This is referred to as ICANN (independent component analysis neural
network combination). Experiments were conducted and the results demonstrate a marked improvement in
the accuracy. The other advantages of this system are that it is suitable for real time operations and it is easy
to train by a lay user.