Validity and Reliability of Surface Electromyography in the Assessment of Primary Muscle Tension Dysphonia

Is Surface Electromyography (sEMG) a Useful Tool in Identifying Muscle Tension Dysphonia? An Integrative Review of the Current Evidence

OBJECTIVE

This integrative review aims to determine the quality level of evidence on using surface electromyography (sEMG) as a diagnostic tool in identifying muscle tension dysphonia.

METHOD

Two independent reviewers used one search engine and five databases to identify sEMG studies published between January 1980 and December 2020, using a set of specified search terms related to muscle tension dysphonia. The selected articles were systematically evaluated by two independent raters using a modified critical appraisal of diagnostic evidence (m-CADE) form.

RESULTS

Nine articles that satisfied the inclusion criteria were selected from among 576 studies for evaluation. These nine studies showed varied methodological approaches in sEMG measurements, including electrode configuration and position, tasks used in sEMG data collection, outcome measure, and normalization procedures. Five studies showed relatively high m-CADE scores, which were indicative of "suggestive validity and compelling importance". Two studies were rated as "suggestive validity and importance", while two remaining studies were rated as "less suggestive or equivocal validity and importance".

CONCLUSIONS

The review found a moderate level of evidence that sEMG can be a potentially useful tool with diagnostic value in identifying muscle tension dysphonia. However, evidence is not yet available to determine the diagnostic accuracy of sEMG for muscle tension dysphonia. More studies are needed, and it is recommended that future studies involving sEMG and reference measurements should be undertaken using a blinding procedure in order to control any subjective biases. Details of the population that the sEMG has been tested on should be outlined clearly so that spectrum bias could be eliminated or minimized in the application process. Furthermore, it is suggested that a reliable and valid protocol in collecting sEMG data during speech should be developed to minimize the variability of sEMG measures in assessing muscle activities during speech.

Comparison of Laryngeal Palpatory Scale (LPS), With Surface Electromyographic Measures in Patients with Muscle Tension Dysphonia

OBJECTIVES

The aim of this study was to examine the laryngeal palpatory scale (LPS) to ascertain possible correlation with neck surface electromyography (sEMG).

METHODS

Two otolaryngologists and one certified speech-language pathologist assessed 21 participants (seven women and 14 men; with a mean age of 42.8 years; ranged: 21 to 70 years) with muscle tension dysphonia (MTD) diagnosed with the current version of the LPS rating system. Consequently, relationships between LPS and objective measures of sEMG were evaluated using Spearman's rank correlation coefficient (r).

RESULTS

The results show that there was a low to moderate between correlations, (statistically positive and significant in 10 correlations among the examined items/states).

CONCLUSIONS

In conclusion, low-moderate positive correlations between sEMG and LPS ratings were found with particular strength for LPS ratings of tightness and ratings made during dynamic tasks. Further investigations can provide useful evidence for researchers and clinicians to document treatment outcomes by using LPS and sEMG in patients with MTD and leading to the more standardized care and improved information about patient progress.

Methods of Measuring Laryngeal Muscle Tension in Patients with Muscle Tension Dysphonia: A Scoping Review

BACKGROUND

In clinical practice and research relating to Muscle Tension Dysphonia (MTD), several laryngeal muscle tension measurement methods are used to diagnose, to identify specific muscle strengths and deficits, and to measure therapeutic outcomes. The variety and reliability of available measurement methods presents challenges within diagnosis and treatment. The lack of methodical standardization presents a barrier to homogeneous practice in this area. There is a need for a comprehensive scoping review of laryngeal muscle tension measurement methods.

STUDY DESIGN

Scoping review.

OBJECTIVES

(1) To identify current methods of laryngeal muscle measurement which have been developed or tested with people with MTD; and (2) To identify the construct/s measured, reliability, validity, ability to detect change, efficiency and accessibility of identified methods.

METHOD

This scoping review was conducted using the Arksey and O'Malley framework. Studies were identified through searches of 4 major databases. The reviewer independently assessed titles, abstracts, and full-text articles.

RESULTS

Twenty seven papers published from 2000 to 2022 that satisfied the inclusion criteria were selected from 194 studies. The papers showed a variety of approaches with regards to the measurement of laryngeal activity and tension in subjects with MTD. Just over a quarter (25.9%) were reviews of the validity of assessment methods of MTD, including surface electromyography (sEMG), while 22.2% discussed surface electromyography as a measurement of muscle activity in subjects with MTD. 96.3% used a published methodological framework.

CONCLUSIONS

Assessment methods for Primary MTD are multifaceted, including patient history, laryngoscopic examination, and voice-related musculoskeletal features. Potential use of objective measurement methods, including sEMG, Real Time Elastosonography, Magnetic Resonance Imaging was noted. Due to variability in assessment methods and results, there is a need for greater objective practical methodological standardization to ensure accurate diagnosis, appropriate care, and chart patient progress.

Exploring the Characteristics of Functional Dysphonia by Multimodal Methods

OBJECTIVES

To explore the characteristics of functional dysphonia (FD) using multimodal methods.

METHODS

A total of 47 FD patients and a group of 22 normal controls were enrolled. Subjective auditory-perceptual assessment of the voice, Voice Handicap Index (VHI) 30, acoustic analysis, psychological scales assessment, surface electromyography (sEMG), nasal airflow and thoracoabdominal studies were performed.

RESULTS

FD was mostly triggered by mood changes. Patient self-evaluation was more serious than auditory-perceptual evaluation and objective acoustic analysis. There was no obvious organic disorder observed under laryngoscope in patients with FD, but there were cases of glottic insufficiency and supraglottic compensation. With regards to sEMG, nasal airflow, chest, and abdomen examination results: (1) sEMG in the normal control group was symmetrical and stable on both sides during rest and phonation, and nasal airflow as well as the chest and abdomen were symmetrical and regular; (2) sEMG in the FD group showed increased recruitment of the sternocleidomastoid muscles, the infra- and suprahyoid muscles, and the cricothyroid muscle, accompanied by prephonation recruitment and postphonation persistence, mainly involving the infra- and suprahyoid muscles; (3) In the FD group, there was shortened inspiratory time, increased chest breathing amplitude, and reduced abdominal breathing, with predominantly chest breathing, and a "breath-holding" phenomenon was observed in some patients, with a significant increase in the number of breaths during the short text task.

CONCLUSIONS

FD occurs mainly in middle-aged women, and there are many triggers. The Hamilton Anxiety/Depression Rating Scale scores were higher, and subjective symptoms were more serious than objective evaluation. No obvious organic changes were seen under laryngoscope, and features such as supraglottic compensation and glottic insufficiency were observed; muscle tension was significantly higher than that of the normal control group, and prephonation recruitment and postphonatory persistence were seen in some patients; the breathing pattern was mainly chest breathing, and the times of breaths during the short text task significantly increased. With identification of the characteristics of FD, the therapy could be focused them.

Lower-limb Nonparametric Functional Muscle Network: Test-retest Reliability Analysis

Objective

Functional muscle network analysis has attracted a great deal of interest in recent years, promising high sensitivity to changes of intermuscular synchronicity, studied mostly for healthy subjects and recently for patients living with neurological conditions (e.g., those caused by stroke). Despite the promising results, the between- and within-session reliability of the functional muscle network measures are yet to be established. Here, for the first time, we question and evaluate the test-retest reliability of non-parametric lower-limb functional muscle networks for controlled and lightly-controlled tasks, i.e., sit-to-stand, and over-the-ground walking, respectively, in healthy subjects.

Method

Fifteen subjects (eight females) were included over two sessions on two different days. The muscle activity was recorded using 14 surface electromyography (sEMG) sensors. The intraclass correlation coefficient (ICC) of the within-session and between-session trials was quantified for the various network metrics, including degree and weighted clustering coefficient. In order to compare with common classical sEMG measures, the reliabilities of the root mean square (RMS) of sEMG and the median frequency (MDF) of sEMG were also calculated.

Results

The ICC analysis revealed superior between-session reliability for muscle networks, with statistically significant differences when compared to classic measures.

Conclusion and Significance

This paper proposed that the topographical metrics generated from functional muscle network can be reliably used for multi-session observations securing high reliability for quantifying the distribution of synergistic intermuscular synchronicities of both controlled and lightly controlled lower limb tasks. In addition, the low number of sessions required by the topographical network metrics to reach reliable measurements indicates the potential as biomarkers during rehabilitation.

Towards Evaluating Pitch-Related Phonation Function in Speech Communication Using High-Density Surface Electromyography

Pitch, as a sensation of the sound frequency, is a crucial attribute toward constructing a natural voice for communication. Producing intelligible sounds with normal pitches depend on substantive interdependencies among facial and neck muscles. Clarifying the interrelations between the pitches and the corresponding muscular activities would be helpful for evaluating the pitch-related phonating functions, which would play a significant role both in training pronunciation and in assessing dysphonia. In this study, the speech signals and the high-density surface electromyography (HD sEMG) signals were synchronously acquired when phonating [a:], [i:], and [ә:] vowels with increasing pitches, respectively. The HD sEMG energy maps were constructed based on the root mean square values to visualize spatiotemporal characteristics of facial and neck muscle activities. Normalized median frequency (nMF) and root-mean square (nRMS) were correspondingly extracted from the speech and sEMG recordings to quantitatively investigate the correlations between sound frequencies and myoelectric characteristics. The results showed that the frame-wise energy maps built from sEMG recordings presented that the muscle contraction strength increased monotonously across pitch-rising, with left-right symmetrical distribution for the face/neck. Furthermore, the nRMS increased at a similar rate to the nMF when there were rising pitches, and the two parameters had a significant correlation across different vowel tasks [(a:) (0.88 ± 0.04), (i:) (0.89 ± 0.04), and (ә:) (0.87 ± 0.05)]. These findings suggested the possibility of utilizing muscle contraction patterns as a reference for evaluating pitch-related phonation functions. The proposed method could open a new window for developing a clinical approach for assessing the muscular functions of dysphonia.

Integrative Review and Framework of Suggested Mechanisms in Primary Muscle Tension Dysphonia

PURPOSE

Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.

METHOD

PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.

RESULTS

Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.

CONCLUSIONS

The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19586065.

Changes in kinematics and work physiology during progressive lifting in healthy adults

PURPOSE

To analyze progression of changes in kinematics and work physiology during progressive lifting in healthy adults.

METHODS

Healthy participants were recruited. A standardized lifting test from the WorkWell Functional Capacity Evaluation (FCE) was administered, with five progressive lifting low series of five repetitions. The criteria of the WorkWell observation protocol were studied: changes in muscle use (EMG), heart rate (heart rate monitor), base of support, posture and movement pattern (motion capture system). Repeated measures ANOVA's were used to analyze changes during progressive workloads.

RESULTS

18 healthy young adults participated (8 men, 10 women; mean age 22 years). Mean maximum weight lifted was 66 (±3.2) and 44 (±7.4) kg for men and women, respectively. With progressive loads, statistically significant (p < 0.01) differences were observed: increase in secondary muscle use at moderate lifting, increase of heart rate, increase of base of support and movement pattern changes were observed; differences in posture were not significant.

CONCLUSIONS

Changes in 4 out of 5 kinematic and work physiology parameters were objectively quantified using lab technology during progressive lifting in healthy adults. These changes appear in line with existing observation criteria.

Clinical and Electromyographic Assessment of Swallowing in Individuals with Functional Dysphonia Associated with Dysphagia Due to Muscle Tension or Atypical Swallowing

Introduction: Over the past few years, attention has been paid to the coexistence of dysphonia with dysphagia, in the context of functional disorders. The aim of this work was to objectify logopaedic examination of dysphonic patients with coexisting swallowing difficulties by surface electromyography. Methods: The material of the work included 58 patients with muscle tension dysphonia (MTD). Each patient underwent otolaryngologic, phoniatric and logopaedic examination. We collected information about medical history and asked patients to fill out Reflux Symptom Index (RSI), Eating Assessment Tool (EAT-10), Dysphagia Handicap Index (DHI) and Swallowing Disorder Scale (SDS). The algorithm of dysphagia diagnostics in our clinic assumes parallel surface electromyography (SEMG) during Functional Endoscopic Evaluation of Swallowing. Results: In comparison to patients suffering from atypical swallowing, patients with muscle tension dysphagia (MTDg) obtained higher values from almost all questionnaires. Logopaedic evaluation revealed abnormalities in the structure and efficiency of the articulatory organs and in the assessment of primary functions. Patients with more abnormalities in logopaedic examination had significantly higher infrahyoid muscle activity during swallowing observed in EMG. Patients with non-normative swallowing pattern had significantly greater asymmetry of the average and maximum amplitude of masseters, as well as submental muscles. Patients with higher percent of muscles asymmetry gained higher scores in questionnaires. Conclusions: Surface electromyography objectifies logopaedic examination of patients with swallowing difficulties. The results of this work showed that, apart from longer swallows, patients with MTDg differ from patients with non-normative swallowing patterns in the muscle activity measured by SEMG, abnormalities in logopaedic evaluation and the severity of complaints reported by patients.

Voz cantada y Electromiografía de Superficie: Un estudio comparativo de la actividad muscular en cantantes formados y no formados

En los últimos años ha habido un incremento del uso de la Electromiografía de Superficie en logopedia, lo que se evidencia en el número creciente de publicaciones en este área en revistas científicas. Este instrumento permite presentar de forma objetiva y precisa la actividad mioeléctrica en tiempo real, es no invasiva y se percibe de fácil aplicación. El objetivo de este trabajo es comparar la actividad mioeléctrica de los músculos maseteros, suprahioideos y esternoicleidomastoideos de cantantes con y sin entrenamiento vocal reglado a través de la Electromiografía de Superficie durante la realización de un fonetograma. La muestra estuvo conformada por 12 sopranos con edades entre 19 y 29 años, 6 con formación reglada en canto y 6 sin formación. Previo a la recogida de datos se calibró el sistema de análisis acústico a través de un calibrador y un dosímetro. Las muestras se recogieron en un gabinete insonorizado, previo consentimiento informado de los participantes. Se fijaron los electrodos en cada uno de los músculos, tanto derechos como izquierdos y se llevó a cabo el protocolo de registro de la actividad mioeléctrica. Se observaron diferencias estadísticamente significativas a nivel de los músculos esternocleidomastoideos, siendo mayor su actividad en los cantantes formados respecto a los no formados. No se obtuvieron diferencias significativas en los otros músculos estudiados. Puede concluirse que los cantantes con formación reglada presentan mayor actividad a nivel de músculos esternocleidomastoideos respecto a los no formados. Es necesario seguir investigando con muestras más amplias para llegar a resultados más concluyentes.