scholarly journals Surface Electromyography for Identification of Pre-Phonatory Activity

2021 ◽  
Author(s):  
Hardik Kothare ◽  
Mark S Courey ◽  
Katherine C Yung ◽  
Sarah L Schneider ◽  
Srikantan Nagarajan ◽  
...  
Keyword(s):  
Surface Emg ◽  
Needle Electrode ◽  
Surface Electrode ◽  
Established Method ◽  
Surface Electrodes ◽  
Thyrohyoid Membrane ◽  
Laryngeal Emg ◽  
Emg Electrodes ◽  
Botox Injection ◽  
Thyroarytenoid Muscle

Surface electrode EMG is an established method for studying biomechanical activity. It has not been well studied in detecting laryngeal biomechanical activity of pre-phonatory onset. Our aims were to compare the sensitivity of surface EMG in identifying pre-phonatory laryngeal activity to needle electrode laryngeal EMG and to compare the pre-phonatory period in patients with adductor laryngeal dystonia (ADLD) with that in controls. ADLD patients (n = 10) undergoing needle LEMG prior to Botox injection and participants with normal voices (n = 6) were recruited. Surface EMG electrodes were placed over the cricoid ring and thyrohyoid membrane. Needle EMG electrodes were inserted into the thyroarytenoid muscle. EMG and auditory output samples were collected during phonation onset. Tracings were de-identified and evaluated. Measurements of time from onset in change of the amplitude and motor unit frequency on the interference pattern to onset of phonation were calculated by two blinded raters. 42 of 71 patient and 40 of 50 control tracings were available for analysis. Correlation for pre-phonatory time between electrode configuration was 0.70 for patients, 0.64 for controls and 0.79 for all the data combined. Inter-rater correlation was 0.97 for needle and 0.96 for surface electrodes. ADLD patients had a longer pre-phonatory time than control subjects by 169.48ms with surface electrode and 140.23ms with needle electrode (p < 0.001). Surface EMG demonstrates equal reliability as Needle EMG in detecting pre-phonatory activity in controls and subjects. Patients with ADLD have a significantly prolonged pre-phonatory period when compared with controls.

scholarly journals Effects of Sampling Frequency and Sample Window Size on Median Frequency of Surface EMG

2019 ◽  
Vol 63 (1) ◽  
pp. 1369-1372
Author(s):  
Pramiti Sarker ◽  
Gary Mirka
Keyword(s):  
Biceps Brachii ◽  
Window Size ◽  
Elbow Flexion ◽  
Surface Emg ◽  
Sampling Frequency ◽  
Emg Activity ◽  
Median Frequency ◽  
Surface Electrodes ◽  
Emg Signal ◽  
Sample Window

Muscle fatigue can be evaluated through the assessment of the downward shift in the median frequency (MDF) of the electromyographic (EMG) signal collected through surface electromyography. Previous research has shown that the value of MDF may be affected by sampling parameters. The purpose of this study was to quantify the combined effect of different sampling frequencies and window sizes on the calculated MDF. A sample of 24 participants performed a simple static elbow flexion exertion (15% MVC) and the EMG activity of the biceps brachii was periodically sampled using surface electrodes for four seconds at a frequency of 4096 Hz as the biceps brachii became fatigued. These collected data were then down-sampled to create a dataset of four window sizes (1s, 2s, 3s, and 4s) and five sampling frequencies (256 Hz, 512 Hz, 1024 Hz, 2048 Hz, and 4096 Hz). Median frequencies were calculated for each combination of sampling frequency and window size and then compared with the 4096 Hz / 4 s condition (considered gold standard) and the errors were calculated. Results suggest the use of a minimum sampling frequency of 512 Hz and a window size of 4s.

EMG Analysis of Patients with Unilateral Neck Pain

1999 ◽  
Vol 8 (1) ◽  
pp. 32-42 ◽  
Author(s):  
Robert L. Whalen ◽  
Steven P. Konstant ◽  
Teddy W. Worrell ◽  
Sam Kegerreis
Keyword(s):  
Neck Pain ◽  
Muscle Activity ◽  
Physical Therapist ◽  
Surface Emg ◽  
High Variability ◽  
Emg Activity ◽  
Upper Trapezius ◽  
Visual Analog Scales ◽  
Vas Scores ◽  
Emg Electrodes

The purpose of this study was to determine whether differences exist in EMG activity between involved and uninvolved upper trapezius muscles in participants with unilateral neck pain. Thirteen volunteers, seen by a physical therapist, gave informed consent. Surface EMG electrodes were placed on involved and uninvolved upper trapezius muscles. Root mean squared EMG activity was measured. Visual analog scales (VASs) for pain were used for each side. Reliability data indicated high ICC (2,1) but also large SEMs and CVs. EMG activity increased from resting to shrugging to abducting positions. Participants perceived greater pain on the involved side than the uninvolved side. EMG readings for individuals were consistent, however, between participants. EMG had high variability. Although participants' VAS scores were consistent with their reports of unilateral neck pain, surface EMG readings did not support the existence of increased muscle activity on the involved side.

Comparison of Surface to Indwelling Extrinsic Finger Muscle EMG during use of Computer Pointing Devices

1998 ◽  
Vol 42 (6) ◽  
pp. 541-545 ◽  
Author(s):  
Melissa Jacobson ◽  
David Rempel ◽  
Bernard Martin ◽  
Peter Keir ◽  
Jack Dennerlein
Keyword(s):  
Muscle Activity ◽  
Cross Correlation ◽  
Surface Emg ◽  
Flexor Digitorum Profundus ◽  
Variable Cross ◽  
Surface Electrodes ◽  
Extensor Indicis Proprius ◽  
Flexor Digitorum ◽  
Estimated Error

Differences between indwelling and surface electromyography (EMG) were quantified by simultaneously recording extrinsic muscle activity of the index finger (flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP), extensor indicis proprius (EIP), and extensor digitorum communis (EDC)) in a laboratory-based study. Eleven subjects performed computer-related pointing and dragging tasks using a mouse, pen and tablet, touchpad, and trackball. Surface electrodes poorly estimated FDP activity as demonstrated by low and variable cross-correlation values (0.47–0.64) and variable, high estimated error (RMS difference=11–46%MVC). Surface electrodes estimated FDS activity well (cross-correlation=0.79; RMS difference=11%MVC) when hand and forearm posture changes were minimized. Differences in forearm supination and pronation reduced the quality of FDS muscle activity estimation. Surface electrodes estimated EIP and EDC activity well with high cross-correlation values (0.77–0.84) and low RMS differences (8–12%MVC). Surface EMG can be used to assess EIP and EDC activity, and FDS activity when posture changes are minimized, during pointing device tasks. Surface EMG does not accurately assess FDP activity.

scholarly journals Could Relative Movement Between the Adductor Muscles and the Skin Invalidate Surface Electromyography Measurement?

2020 ◽  
Vol 36 (5) ◽  
pp. 319-325 ◽  
Author(s):  
Walaa M. Elsais ◽  
Stephen J. Preece ◽  
Richard K. Jones ◽  
Lee Herrington
Keyword(s):  
Surface Electromyography ◽  
Surface Emg ◽  
Ultrasound Measurement ◽  
Relative Movement ◽  
Adductor Muscles ◽  
Flexion Extension ◽  
Close Proximity ◽  
Electrode Positioning ◽  
Hip Flexion ◽  
Emg Electrodes

The superficial hip adductor muscles are situated in close proximity to each other. Therefore, relative movement between the overlying skin and the muscle belly could lead to a shift in the position of surface electromyography (EMG) electrodes and contamination of EMG signals with activity from neighboring muscles. The aim of this study was to explore whether hip movements or isometric contraction could lead to relative movement between the overlying skin and 3 adductor muscles: adductor magnus, adductor longus, and adductor gracilis. The authors also sought to investigate isometric torque–EMG relationships for the 3 adductor muscles. Ultrasound measurement showed that EMG electrodes maintained a position which was at least 5 mm within the muscle boundary across a range of hip flexion–extension angles and across different contraction levels. The authors also observed a linear relationship between torque and EMG amplitude. This is the first study to use ultrasound to track the relative motion between skin and muscle and provides new insight into electrode positioning. The findings provide confidence that ultrasound-based positioning of EMG electrodes can be used to derive meaningful information on output from the adductor muscles and constitute a step toward recognized guidelines for surface EMG measurement of the adductors.

Placement of forearm surface EMG electrodes in the assessment of hand loading in manual tasks

Ergonomics ◽  
2013 ◽  
Vol 56 (7) ◽  
pp. 1159-1166 ◽  
Author(s):  
Esa-Pekka Takala ◽  
Risto Toivonen
Keyword(s):  
Surface Emg ◽  
Manual Tasks ◽  
Emg Electrodes

Standard Values of the Amplitude of Jaw Jerk Action Potential and Differences Due to Age, Sex and L-Dopa Treatment

1979 ◽  
Vol 58 (4) ◽  
pp. 1337-1340 ◽  
Author(s):  
Sven-Erik Widmalm ◽  
Harry Gill ◽  
Sven Widmalm ◽  
Sven Gottmar Ericsson
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Diagnostic Value ◽  
Surface Emg ◽  
Elderly Subjects ◽  
Before And After ◽  
Standard Values ◽  
Males And Females ◽  
Masticatory System ◽  
Emg Electrodes

The amplitude of the jaw jerk action potential (MSP) is a parameter with possible diagnostic value. Standard values have, however, not yet been established. MSPs were recorded using surface EMG electrodes in the masseter and the anterior temporal muscles of young and elderly healthy males and females. The group means ranged from 0.26 to 2.11 mV in the masseter and from 0.17 to 0.81 mV in the anterior temporalis. The amplitude of MSP was higher in females than in males, decreased in elderly subjects and lower in the temporalis than in the masseter. The jaw jerk action potentials also were recorded in four subjects before and after L-Dopa administration. The amplitude increased by about 90%. It is concluded that the parameter MSP amplitude can be useful in the studies of muscle spindle sensitivity and the influence of various physiological, pathophysiological and pharmacological factors on the nervous regulation and muscle function in the masticatory system.

scholarly journals Volitional control of reflex cough

2012 ◽  
Vol 113 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Karen W. Hegland ◽  
Donald C. Bolser ◽  
Paul W. Davenport
Keyword(s):  
Cerebral Cortex ◽  
Surface Emg ◽  
Emg Activity ◽  
Alternative Behavior ◽  
Cough Reflex ◽  
Expiratory Muscles ◽  
Output Characteristics ◽  
Cough Airflow ◽  
Emg Electrodes ◽  
Reflex Cough

Multiple studies suggest a role for the cerebral cortex in the generation of reflex cough in awake humans. Reflex cough is preceded by detection of an urge to cough; strokes specifically within the cerebral cortex can affect parameters of reflex cough, and reflex cough can be voluntarily suppressed. However, it is not known to what extent healthy, awake humans can volitionally modulate the cough reflex, aside from suppression. The aims of this study were to determine whether conscious humans can volitionally modify their reflexive cough and, if so, to determine what parameters of the cough waveform and corresponding muscle activity can be modified. Twenty adults (18–40 yr, 4 men) volunteered for study participation and gave verbal and written informed consent. Participants were seated and outfitted with a facemask and pneumotacograph, and two surface EMG electrodes were positioned over expiratory muscles. Capsaicin (200 μM) was delivered via dosimeter and one-way (inspiratory) valve attached to a side port between the facemask and pneumotachograph. Cough airflow and surface EMG activity were recorded across tasks including 1) baseline, 2) small cough (cough smaller or softer than normal), 3) long cough (cough longer or louder than normal), and 4) not cough (alternative behavior). All participants coughed in response to 200 μM capsaicin and were able to modify the cough. Variables exhibiting changes include those related to the peak airflow during the expiratory phase. Results demonstrate that it is possible to volitionally modify cough motor output characteristics.

scholarly journals A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1261 ◽  
Author(s):  
Bret Contreras ◽  
Andrew D. Vigotsky ◽  
Brad J. Schoenfeld ◽  
Chris Beardsley ◽  
John Cronin
Keyword(s):  
Body Mass ◽  
Isometric Contraction ◽  
Gluteus Maximus ◽  
Surface Emg ◽  
Future Research ◽  
Maximum Voluntary Isometric Contraction ◽  
Heterogeneous Samples ◽  
Hip Extension ◽  
Emg Electrodes

Background.The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90°) hip extension against manual resistance applied to the distal thigh (PRONE), to a novel position, the standing glute squeeze (SQUEEZE).Methods.Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg), before three maximum voluntary isometric contraction (MVIC) trials for each position were obtained in a randomized, counterbalanced fashion.Results.No statistically significant (p< 0.05) differences were observed between PRONE (upper: 91.94%; lower: 94.52%) and SQUEEZE (upper: 92.04%; lower: 85.12%) for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects.Conclusions.In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.

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