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Biomedical subjects

F Bérzin

Publications and source records attributed to F Bérzin.

At least 19 recordsLinked to original sources
PubMed2005

Preliminary rapport on head posture and muscle activity in subjects with class I and II.

Forward head posture may cause alterations in the stomatognathic system, including changes in the muscle activity of the masticatory muscles and dental occlusion alterations. Considering the need for further understanding of the relationship between the stomatognathic system and the cervical region, the purpose of this study was to analyse the head posture and the electromyographic (EMG) activity of the anterior portion of temporal and masseter muscles bilaterally among bruxist's subjects with different dental occlusion classifications using the Angle method. The study consisted of 20 female volunteers, between the ages of 17 and 27 years. They were separated into two groups (class I and class II occlusions) according to a dentist-performed evaluation. An assessment of forward head posture was conducted using a photographic technique (angular calculus) combined with a clinical analysis. In the EMG analyses, active differential surface electrodes (Ag) were utilized and were placed bilaterally on the belly of masseter and temporal muscles, perpendicular to the muscles fibres. The EMG signal recorded during bilateral isotonic mastication, was presented using the Root Mean Square and was processed by Matlab software. The results indicated that the EMG responses of temporal and masseter muscles tend to be modified by occlusion alteration class II. Subjects with class II occlusion tended to present more occurrence of forward head posture with alterations in the muscle activity pattern between masseter and temporal muscles.

Adolescent↗
PubMed2002

A physiotherapeutic approach to craniomandibular disorders: a case report.

This is a case report of a 19-year-old female who presented with a unilateral weakness of the right masseter muscle evidenced by electromyographic examination. The presence of a mandibular deviation to the right during opening because of this weakness was treated with neuromuscular electrical stimulation (NMES). After the physiotherapeutic treatment, the electrical activity of the right masseter muscle increased during function and the mandibular deviation disappeared. Electromyography (EMG) can have a useful role in the determination of the muscular profile, and for evaluating therapeutics.

Adult↗
PubMed1999

Electromyographic analysis of the superior belly of the omohyoid muscle and anterior belly of the digastric muscle in tongue and head movements.

The participation of the superior belly of the omohyoid muscle and anterior belly of the digastric muscle in tongue and head movements was studied eletromyographically in 20 normal young volunteers. A pair of monopolar electrodes was used in each muscle for simultaneous recording of their actions. The muscles act in the following tongue movements: protrusion, right and left lateral movements, placement of the tip of the tongue on soft and hard palates and on the floor of the mouth. The strongest levels of activity of the superior belly of the omohyoid muscle were observed in the placement of the tip of the tongue on the soft palate, coincidentally with a greater dislocation of hyoid bone. Both of the muscles studied did not participate in the head's kinesiology.

Electromyography↗
PubMed1999

Influence of myofunctional therapy on the perioral muscles. Clinical and electromyographic evaluations.

The purpose of this study was to evaluate the influence of oral myofunctional therapy on the superior and inferior orbicularis oris (OOS and OOI) and mentalis (MT) muscles at rest and with lips closed in mouth breathing patients with no nasal airway obstruction. The sample consisted of 13 children aged 5-10 years. Clinical and electromyographic evaluations were performed before and after treatment. The results showed that muscles (P < 0.05) and functions (P < 0.01) improved after therapy, which can be observed by clinical evaluations. The electrical activity increase between rest and closed lip positions was statistically significant for the muscles studied. Before therapy the significant minimal level (s.m.l.) was P < 0.01 and after therapy it was P < 0.05. When the difference between the rest and closed lip positions before and after therapy was compared, a statistically significant decrease (P < 0.05) in the electrical activity of the OOI and MT muscles was observed. There was no correlation between the root-mean-square (RMS) of the OOI and MT muscles with the morphological and functional evaluations. The therapy can improve morphology and function of the muscles in mouth breathing patients with no nasal airway obstruction.

Child↗
PubMed1999

Evaluation of electromyographic activity and heart rate responses to isometric exercise. The role played by muscular mass and type.

The purpose of the present study was to examine the relationship between the electromyographic (EMG) activity and heart rate (HR) responses induced by isometric exercise performed by knee extension (KE) and flexion (KF) in men. Fifteen healthy male subjects, 21 +/- 1.3 years (mean +/- SD), were submitted to KE and KF isometric exercise tests at 100% of maximal voluntary contraction (MVC). The exercises were performed with one leg (right or left) and with two legs simultaneously, for 10 s in the sitting position with the hip and knee flexed at 90 degrees. EMG activity (root mean square values) and HR (beats/min) were recorded simultaneously both at rest and throughout the sustained contraction. The HR responses to isometric exercise in KE and KF were similar when performed with one and two legs. However, the HR increase was always significantly higher in KE than KF (P < 0.05), whereas the EMG activity was higher in KE than in KF (P < 0.05), regardless of the muscle mass (one or two legs) involved in the effort. The correlation coefficients between HR response and the EMG activity during KE (r = 0.33, P > 0.05) and KF (r = 0.15, P > 0.05) contractions were not significant. These results suggest that the predominant mechanism responsible for the larger increase in HR response to KE as compared to KF in our study could be dependent on qualitative and quantitative differences in the fiber type composition found in each muscle group. This mechanism seems to demand a higher activation of motor units with a corresponding increase in central command to the cardiovascular centers that modulate HR control.

Adult↗
PubMed1998

Electromyographic study of the temporal, masseter and suprahyoid muscles in the mandibular rest position.

The temporal muscles (anterior position), and the masseter and suprahyoid muscles were studied electromyographically in 15 subjects with ages ranging from 18 to 35 years, showing normal occlusion (Class I of angle), complete dentition and no dysfunction of the stomatognathic system. The volunteers sat comfortably in a chair, keeping the Frankfurt plane parallel to the floor; the muscles were analysed in the mandibular resting position through a number of stages: with minimum exteroceptive stimuli, relaxation with soft music, abolition of the intrabuccal negative pressure through a plastic tube, stress provoked by an electronic game, disocclusion of posterior teeth using the occlusal splint and finally withdrawal of this device. The electromyographic results were analysed statistically. The samples, were analysed for all of the frequencies of motor units, in a 1-min period. It was found that there were statistically significant difference between the relaxation stages as compared with the withdrawal of negative intraoral pressure and mainly with the stress phase, being this only on the suprahyoid muscles, with 5% significance.

Adolescent↗
PubMed1995

Electromyographic analysis of the sternohyoid muscle and anterior belly of the digastric muscle in head and tongue movements.

The sternohyoid muscle and anterior belly of the left digastric muscle were electromyographically studied in 20 young adult volunteer individuals. A surface monopolar electrode and a needle monopolar electrode, inserted into the muscle mass 1.0 cm apart were employed. The muscles acted during the following movements of the tongue; protraction, lateral movements to either side, and placement of the tip of the tongue on the hard and soft palate. It was in the latter movement that the most significant action potentials of the sternohyoid muscle were observed, which coincided with a major displacement of the hyoid bone. Both muscles studied do not take part in the kinesiology of the head.

Adult↗
PubMed1995

Electromyographic analysis of the sternohyoid muscle and anterior belly of the digastric muscle in jaw movements.

The sternohyoid muscle and the anterior belly of the left digastric muscle were studied electromyographically in 20 young adult volunteer individuals. A surface monopolar electrode and a needle monopolar electrode, inserted into the muscle mass 1.0 cm apart were employed. The most significant action of the two muscles was found in the opening of the jaw, during which the sternohyoid muscle presented an isotonic contraction, allowing for displacements of the hyoid bone. They also acted on those movements that included one of the jaw depression components, such as protrusion, lateral movements to either side, and retrusion. They were inactive when the jaw was in the resting position. Both muscles operated simultaneously most of the time, but a synchronization of their actions could not be demonstrated.

Action Potentials↗
PubMed1993

EMG study of the anterior, superior and posterior auricular muscles in man.

Anterior, superior and posterior auricular muscles were studied electromyographically by means of wire electrodes. During ear movement the three muscles acted as a group and the movement was always directed upwards and backwards. The highest electrical activities were observed during natural smiling and yawning. Mouth opening without the drawing backwards of the comissura labiorum and the displacement of galea aponeurotica also produced electrical activity by the auricular muscles, with however, less intensity and in only 50% of the cases studied.

Adult↗
PubMed1980

[Electromyographic analysis of the primary dorsal interosseus muscle of the human hand. I. Movements of the index finger].

An electromyographic study of the musculus interosseus dorsalis was performed on the right hand of 25 young adult male right-handed volunteers. The electrodes, simple coaxial needles, were implanted one at the ulnar head and the other at the radial head of the muscle. The muscles were analyzed during free movements of the index and against resistance. The same movements were done in four different positions of the forearm and hand, without variation in the results for each one of the movements. There was no significant difference between the activities of the ulnar head and radial head. During freely performed movements, muscle activity was recorded only during abduction. During movements against resistance, muscle activity was completely nil only during adduction; during the remaining movements, however, moderate (2+), strong (3+) and very strong activity (4+) was recorded.

Adolescent↗
PubMedDate not supplied

The effect of free isotonic and maximal isometric contraction exercises of the hip adduction on vastus medialis oblique muscle: an electromyographic study.

The purpose of this study was to analyse the activity of the vastus medialis oblique (VMO) muscle electromyographically during free isotonic and maximal isometric contraction of the hip adduction with knee extension performing exercises at sitting and in decubitus lateralis positions. Using a 8 channels Nicolet Electromyograph and Beckman surface mini electrodes, the activity of the vastus medialis oblique muscle was recorded among 15 healthy subjects, aged 19 to 33 years, (mean = 24.4, SD = 4.1) without prior knee and hip joints pathology. The sign was recorded in root mean square (RMS), expressed in microvolts. The data were statistically calculated employing an analysis of variance (ANOVA) and the Tukey test, at 5% of significance. The results showed that the electromyographic (EMG) activity of the vastus medialis oblique muscle was significantly greater in both exercises of maximal contraction when compared with free isotonic at decubitus lateralis. On the other hand, there was no significant difference of the electromyographic activity of the vastus medialis oblique muscle between the two exercises of maximal isometric contraction. These findings, within the experimental conditions used, suggest that prior stages of patellofemoral dysfunction, the exercises of hip adduction with knee extension could be performed isometrically or isotonically, at sitting and in decubitus lateralis positions, depending on the biological conditions of each patient.

Adult↗
PubMedDate not supplied

Electromyographic analysis of the extending muscles of the knee during functional activities.

The purpose of this study is to analyze the behavior of electrical activity of the muscles vastus medialis oblique (VMO), vastus medialis long (VML), and, rectus femoris (RF) during functional activities. The electromyography of the VMO, VML and RF muscles were analyzed in ten healthy volunteers. Signs were collected through superficial electrodes and a electrogoniometer, connected to a signal condition module. The analysis of the results after treating the signals shows us that there is a similar electromyographical behavior in the three studied muscles. Therefore, these discoveries suggest a common electrical behavior pattern especially between VMO and VL muscles in healthy volunteers.

Adult↗
PubMedDate not supplied

Quantitative end qualitative analysis of the electrical activity of rectus abdominis muscle portions.

The purpose of this study was to investigate the electrical behavior pattern of the Rectus abdominis muscle by qualitative and quantitative analysis of the electromyographic signal obtained from its superior, medium and inferior portions during dynamic and static activities. Ten voluntaries (aged X = 17.8 years, SD = 1.6) athletic males were studied without history of muscle skeletal disfunction. For the quantitative analysis the RMS (Root Mean Square) values obtained in the electromyographic signal during the isometric exercises were normalized and expressed in maximum voluntary isometric contraction percentages. For the qualitative analysis of the dynamic activity the electromyographic signal was processed by full-wave rectification, linear envelope and normalization (amplitude and time), so that the resulting curve of the processed signal was submitted to descriptive graphic analysis. The results of the quantitative study show that there is not a statistically significant difference among the portions of the muscle. Qualitative analysis demonstrated two aspects: the presence of a common activation electric pattern in the portions of Rectus abdominis muscle and the absence of significant difference in the inclination angles in the electrical activity curve during the isotonic exercises.

Adolescent↗
PubMedDate not supplied

Occipitofrontalis muscle: functional analysis revealed by electromyography.

The occipital and frontal bellies of the right occipitofrontalis muscle were studied electromyographically in thirty volunteers in various movements, using a special steel electrode (80 microns diameter). The occipital and frontal bellies have independent actions despite the galea aponeurotica. The frontal belly initially raises the homolateral eyebrow, followed by a displacement of the galea aponeurotica, drawing the scalp forward; therefore it is active in the formation of the transversal wrinkling in the forehead. The occipital belly eventually can be active during raising of the eyebrown, nevertheless it does not interfere with the action of the frontal belly. The occipital belly alone is responsible for drawing back the galea aponeurotica. The occipital belly is also active during smiling and yawning, and can be active during the movements of the auricula.

Adult↗
PubMedDate not supplied

Electromyographic study of the upper, middle and lower portion of the trapezius muscle in the circumduction movement of the arm on a shoulder wheel apparatus.

The upper, middle and lower portions of the trapezius muscle were analysed electromyographically (using a TECA TE-4 electromyograph and a single coaxial needle) in 20 healthy volunteers, during a circumduction movement of the arm, on a shoulder wheel apparatus. All three portions of the muscle were active, but the elevation phase of the arm was more pronounced in movements performed clockwise while the lowering phase was more manifest in movements performed counterclockwise. The position of the wheel gauntlet did not interfere significantly with the results.

Adolescent↗