ABSTRACT
ObjectiveTo test the inter-tester reliability and test-retest reliability of MyotonPRO for evaluating neck and shoulder muscle performance parameters in patients with unilateral chronic neck pain, observe the difference of muscle performance between the healthy and affected sides of patients with chronic neck pain, and analyze the factors that cause the imbalance of muscle performance in patients with chronic neck pain. MethodsFrom January to June, 2023, 32 patients with unilateral chronic neck pain in Guangdong Second Traditional Chinese Medicine Hospital were selected. Two testers used the same MyotonPRO equipment to measure the muscle tone, muscle hardness and muscle elasticity on both sides of the sternocleidomastoid muscle and the upper trapezius muscle in the relaxed position. Tester 1 repeated the measurement after an interval of 30 minutes, and Tester 2 was measured within the time interval between the two measurements of Tester 1. The intraclass correlation coefficient (ICC), standard error of mean (SEM) and minimum detectable change (MDC) were calculated simultaneously. The measurement results were plotted into Bland-Altman diagram and systematic bias analysis was performed. The difference in muscle characteristics between the affected side and the healthy side was compared. At the same time, the Visual Analogue Scale (VAS) score and body mass index (BMI) of the subjects were collected for correlation analysis. ResultsExcept the sternocleidomastoid muscle elasticity of the affected side (ICC = 0.697), the inter-tester reliability of all other parameters was high to very high (ICC = 0.719 to 0.952, SEM = 0.04 to 6.53, MDC = 0.12 to 18.11). The test-retest reliability of all parameters was high (ICC = 0.883 to 0.981, SEM = 0.03 to 5.72, MDC = 0.09 to 15.84). Bland-Altman plot analysis showed that the scatter distribution was consistent. The muscle tone, muscle hardness and muscle elasticity of sternocleidomastoid muscle and upper trapezius muscle were higher on the affected side than on the healthy side (t > 2.846, P < 0.05). The asymmetry index of tension, hardness and elasticity of upper trapezius muscle and sternocleidomastoid muscle was significantly positively correlated with VAS score and BMI (r > 0.385, P < 0.05). ConclusionMyotonPRO has good inter-tester reliability and retest reliability in evaluating the muscle performance of both sides of patients with chronic neck pain. The muscle tone, muscle hardness and muscle elasticity of sternocleidomastoid muscle and upper trapezius muscle on the affected side were higher than on the healthy side, and the difference of muscle performance was positively correlated with pain and BMI.
ABSTRACT
Objective To survey cervical myoelectric signals during craniocervical flexion, neutral and extension postures, and to explore the evidence that proper head position can alleviate cervical muscle fatigue in a lateral recumbent position. Methods Surface electromyography (sEMG) signals were detected from the sternocleidomastoid, upper trapezius and erector spinae muscles of 30 young subjects bilaterally during craniocervical flexion,neutral and extension postures in the left lateral recumbent position. The integrated trace area (IEMG) and median frequency (MF) were estimated. Results The average IEMG of the sternocleidomastoid muscles was significantly lower in flexion than in extension bilaterally. The average IEMG of the erector spinae muscles was lower in extension than in flexion bilaterally, and the difference was again significant. The IEMGs of the upper trapezius muscle showed no significant difference on average in the three postures bilaterally. There was no significant MF difference in any of the muscles. Conclusions The muscles in the cervical back were less activated during craniocervical extension in a lateral recumbent position. A little cranicocervical extension is optimal while resting in a lateral recumbent position.
ABSTRACT
OBJECTIVE: The aim of this study was to investigate whether muscle fatigue indices obtained using surface electromyography and calculated in the time and frequency domains would be capable of objectively diagnosing pain and discriminating between subjects with and without pain in the upper trapezius muscle and the lower back muscles. METHODS: Forty-seven individuals underwent a muscle fatigue test for thirty-five seconds at 80% of the maximal voluntary contraction (MVC), while EMG and muscle force data were recorded. The RMS value and the median frequency (MF) were calculated within consecutive one-second windows. Linear regression analysis was used to obtain the slope coefficients and the respective y-axis intercept values, which were considered to be localized muscle fatigue indices. RESULTS: In the frequency domain, the slope coefficients were negative for both muscles, while in the time domain, the coefficient for the upper trapezius was positive and the coefficient for the lower back muscles was negative (p<0.01). Significant differences were also found in the frequency domain between subjects with and without pain in the upper trapezius (p<0.01). The subjects with pain had significantly lower force values than the subjects without pain (p<0.05), in both the upper trapezius and the lower back muscles. CONCLUSION: The force values associated with the fatigue indices (MF slope and y-axis intercept) were able to predict the presence of pain in the upper trapezius (p<0.05), but not in the lower back muscles.
OBJETIVO: A proposta do estudo foi investigar se índices de fadiga, obtidos a partir de eletromiografia de superfície, calculados no domínio do tempo e da frequência, são capazes de diagnosticar a dor objetivamente, discriminando entre sujeitos com e sem dor no trapézio superior e nos músculos lombares. MÉTODOS: Quarenta e sete indivíduos foram submetidos a um teste de fadiga muscular por 35s a 80% da contração voluntária máxima (CVM), enquanto EMG e força muscular foram registradas. O valor RMS e a mediana da frequência (MF) foram calculados em janelas consecutivas de 1s. Análise de regressão linear foi utilizada para obter os coeficientes de inclinação e seus respectivos valores de interseção no eixo y, os quais foram considerados índices de fadiga muscular localizada. RESULTADOS: Os coeficientes de inclinação analisados no domínio da frequência apresentaram comportamento similar, sendo negativos para ambos os músculos, enquanto que, no domínio tempo, o trapézio superior apresentou coeficientes positivos, e músculos lombares, coeficientes negativos (p<0,01). Diferenças significativas também foram identificadas no domínio da frequência entre os sujeitos com e sem dor no trapézio superior (p<0,01). Os indivíduos com dor apresentaram valores de força significativamente menores que os sujeitos sem dor (p<0,05), tanto nos músculos lombares quanto no trapézio superior. CONCLUSÃO: Os valores de força associados aos índices de fadiga (inclinação da MF e intersecção do eixo y) foram hábeis para predizer a presença de dor no trapézio superior (p<0,05), mas não nos músculos lombares.