Maximum bilateral bite strength and RMS EMG for the diagnosis of myogenic TMD

Aim: The study aimed to evaluate the accuracy of the maximum bilateral molar bite force and the Root Mean Square (RMS) Electromyography (EMG) index of the masticatory muscles in the maximum bilateral molar bite (MMBMax) of women with myogenic Temporomandibular Disorder (TMD) and asymptomatic. Methods: This is a cross-sectional study, composed of 86 women allocated to the TMD Group (n=43) and Control Group (n=43) diagnosis through the Diagnostic Criteria for Temporomandibular Disorders. The maximum bilateral molar bite force was evaluated using a bite dynamometer and the RMS EMG index of the masticatory muscles (anterior temporalis, masseter) during 5 seconds of the MMBMax task. Student t-test was used for data comparison between accuracy of the bite force and RMS EMG of masticatory muscles during the MMBMax. Results: The maximum bilateral molar bite force showed high accuracy (AUC=0.99) for the diagnosis of women with myogenic TMD and asymptomatic women, and the RMS EMG index evaluated during the MMBMax showed a moderate level of accuracy for all masticatory muscles (AUC=0.70 to 0.75). Conclusion: The bilateral bite dynamometer with a surface EMG during bilateral bite can be used to diagnose TMD in young women

Normalization of the electromyographic signals of masticatory muscles during non-habitual chewing activity

There is no consensus on the most appropriate method for normalizing electromyography (EMG) signals from masticatory muscles during isotonic activity. Aim: To analyze the best method for data processing of the EMG signal of the masticatory muscles during isotonic activity (non-habitual chewing), comparing raw data and different types of normalization. Methods: This is a cross-sectional study. Women aged between 18 and 45 years were selected. Anthropometric data were collected (age, height, body mass index ­ BMI, masticatory preference) as well as EMG signal (root mean square ­ RMS) data for the anterior temporal and masseter bilaterally, and for the suprahyoid muscles, during isotonic (non-habitual chewing) and isometric tasks. EMG data were processed offline using Matlab® Software. The normalization of the EMG signal was carried out using the 2nd masticatory cycle, chosen at random, of the 20 cycles collected, the maximum RMS value, and the maximum voluntary contraction (MVC). To analyze the best method of data processing for the isotonic data, the coefficient of variation (CV) was calculated. Descriptive data analysis was adopted, using the mean and standard deviation. ANOVA with repeated measures was used to detect significant differences between the methods of normalization. Statistical significance was set at 5% (α<0.05). Results: The final sample of this research was composed of 86 women. The volunteers presented an average age of 27.83±7.71 years and a mean BMI of 22.85±1.91 Kg/m2. Regarding masticatory preference, 73.25% reported the right side, and 26.75% the left side. Considering the comparison between the methods, the %CV measure of the 2nd cycle showed the lowest variation coefficient during biting for all the muscles from the raw data, RMS Max, and MVC (p=0.001, p=0.003, and p=0.001 respectively). Conclusion: In conclusion, for non-habitual chewing activity, the results of this study recommend data processing using normalization with the second cycle during chewing

Efeito da mobilização das raízes nervosas lombares sobre a força e flexibilidade dos músculos do membro inferior / Effect of the mobilization in lumbar nerve roots on muscle strength and flexibility of the lower limb

Introdução: A mobilização neural é bastante aplicada na pratica clínica. Objetivo: Avaliar o efeito da mobilização neural das raízes lombares na força e flexibilidade dos músculos flexores e extensores do joelho. Métodos: Foram selecionados 14 homens (22,4±2,87 anos) saudáveis. A flexibilidade foi avaliada para flexão de joelho (FJD e FJE), extensão de quadril (EQD e EQE) e coluna lombar (FL). A força muscular foi avaliada para flexão e extensão do joelho. As avaliações foram realizadas antes da técnica (PRÉ), imediatamente após (PÓS1) e uma semana após (PÓS2). Resultados: Nas avaliações PÓS1 e PÓS2 foi observado aumento significativo da força muscular na FJE. Para a flexibilidade, na avaliação PÓS1, observou-se aumento significativo na FJE, EQD e EQE. Conclusão: A técnica de mobilização neural promoveu aumento da força dos músculos flexores de joelho esquerdo e da flexibilidade no movimento de flexão de joelho esquerdo, extensão de quadril direito e esquerdo em homens sedentários saudáveis.

Introduction: Neural mobilization is widely applied in clinical practice. Aim: To evaluate the effect of neural mobilization of the lumbar roots on the strength and flexibility of the knee and hip muscles. Methods: We selected 14 men (22.4 ± 2.87 years) healthy. Flexibility was evaluated during knee flexion movements (KFR and KFL), extension of the hip (HER and HEL) and for the lumbar spine (LS). Assessment of muscle strength was performed for the knee movements. The evaluations were performed before the neural mobilization (PRE), immediately after (POST1) and one week after (POST2). Results: In the POST1 and POST2 was a significant increase in muscle strength in KFL. For flexibility, the POST1 evaluation, it was observed significant increase in KFL, HER, and HEL. In the evaluation POST2, a significant increase flexibility in LS and reduction in KFL. Conclusion: The neural mobilization promoted increased strength of the flexor muscles of the left knee, increased flexibility in the KFL, HER, HEL and LS.

Efeitos da manipulação cervical alta sobre a atividade eletromiográfica dos músculos mastigatórios e amplitude de movimento de abertura da boca em mulheres com disfunção temporomandibular: ensaio clínico randomizado e cego / Los efectos de la manipulación cervical en la actividad electromiográfica de los músculos masticatorios y la amplitud del movimiento de apertura de la boca en mujeres con trastorno temporomandibular: un ensayo clínico aleatorizado y ciego / Effects of upper cervical manipulation on the electromyographic activity of the masticatory muscles and the opening range of motion of the mouth in women with temporomandibular disorder: randomized and blind clinical trial

RESUMO Avaliou-se os efeitos da manipulação cervical alta sobre a atividade eletromiográfica de superfície (sEMG) dos músculos mastigatórios e amplitude do movimento de abertura da boca em mulheres com disfunção temporomandibular (DTM). Foram avaliadas 10 mulheres com diagnóstico de DTM miogênica, segundo o Research Diagnostic Criteria for temporomandibular disorders (RDC/TMD), divididas, aleatoriamente, em grupo experimental (GE) n=5, que recebeu manipulação cervical alta e grupo placebo (GP) n=5, que recebeu manobra sem efeito terapêutico. Cinco intervenções foram aplicadas para ambos os grupos uma vez por semana, e avaliações de pré-intervenção, pós-imediato (após a 1ª intervenção) e pós-tardio (48 horas após a 5ª intervenção) foram realizadas. A atividade sEMG foi processada via raiz quadrada da média e normalizada pelo valor de pico (RMS EMGn). Utilizou-se para comparação os testes t de Student e ANOVA two-way (medidas repetidas), adotando-se como significância o valor de 5%, e o Cohen's d para tamanho de efeito de tratamento. Constatou-se a interação significativa grupo × tempo (p<0,05) no RMS EMGn dos músculos temporal direito e esquerdo, na condição de repouso, assim como para todos os músculos mastigatórios durante contração isométrica máxima de elevação e depressão da mandíbula. Os tamanhos de efeito de tratamento moderado a alto foram observados no GE, destacando-se na avaliação pós-tardia. Foi observado também um aumento significativo (p<0,05) e um alto efeito de tratamento na abertura da boca para o GE. A manipulação cervical alta demonstrou equilibrar o RMS EMGn dos músculos mastigatórios e aumentar a amplitude de movimento de abertura da boca em mulheres com DTM miogênica.

RESUMEN En este estudio se evaluaron los efectos de la manipulación cervical alta sobre la actividad electromiográfica de superficie (SEMG) de los músculos masticatorios y de amplitud del movimiento de apertura de la boca en mujeres con trastorno temporomandibular (TTM). Se evaluaron 10 mujeres con diagnóstico de TTM miogénico, con base en el Research Diagnostic Criteria for temporomandibular disorders (RDC/TMD), las que fueron aleatoriamente divididas en grupo experimental (GE) n=5, que recibió manipulación cervical alta, y grupo placebo (GP) n=5, que recibió maniobra sin efecto terapéutico. Se aplicaron cinco intervenciones para ambos grupos una vez por semana, y se realizaron evaluaciones preintervención, posintervención inmediata (después de la 1a. intervención) y posintervención tardía (48 horas después de la 5a. intervención). La actividad SEMG fue calculada mediante raíz cuadrada de la media y normalizada por el valor de pico (RMS EMGn). Se empleó para comparación los test t de Student y ANOVA two-way (medidas repetidas), y el nivel de significancia de 5%, y para el efecto del tratamiento el Cohen's d. Se encontró la interacción significativa grupo × tiempo (p<0,05) en el RMS EMGn de los músculos temporales derecho e izquierdo, en reposo, así como para todos los músculos masticatorios durante la contracción isométrica máxima de elevación y depresión de la mandíbula. Se observaron efectos de tratamiento moderado a alto en el GE, destacando en la etapa posevaluación tardía. También se observó un aumento significativo (p<0,05) y un alto resultado del tratamiento en la apertura de la boca en el GE. La manipulación cervical alta demostró equilibrar el RMS EMGn de los músculos masticatorios y aumentar la amplitud del movimiento de la apertura de la boca en mujeres con TTM miogénica.

ABSTRACT We evaluated the effects of upper cervical manipulation on the surface electromyographic activity (sEMG) of masticatory muscles and range of motion of the opening movement of the mouth in women with temporomandibular disorders (TMD). We evaluated 10 women with myogenic a TMD diagnosis, according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and divided randomly into an experimental group (EG) n=5, which received upper cervical manipulation, and a placebo group (PG) n=5, which received maneuvers without therapeutic effects. Five interventions were performed in both groups, once a week, with performance of pre-intervention assessments, post-immediate assessments (after 1st intervention) and post-delayed assessments (48 hours after the 5th intervention). The sEMG activity was processed using the root mean square and normalized by the peak value (RMS EMGn). We used for comparison the Student's t-test and ANOVA two-way repeated measures, adopting as significance the amount of 5%, and the Cohen d for treatment effect size. We found a significant interaction of group vs time (p<0.05) in the RMS EMGn of the left and right temporal muscles at rest, as well as for all masticatory muscles during maximal isometric contraction during jaw-elevation and jaw-depression. Treatment effect size, high to moderate, was observed in the EG, especially in the post-delayed assessment. We also observed a significant increase (p<0.05) and a high treatment effect during mouth opening in the EG. The upper cervical manipulation demonstrated a balance of the RMS EMGn of the masticatory muscles and increase the opening range of motion of the mouth in women with myogenic TMD.