Reliability of different methodologies of infrared image analysis of myofascial trigger points in the upper trapezius muscle

BACKGROUND: Infrared thermography is recognized as a viable method for evaluation of subjects with myofascial pain. OBJECTIVE: The aim of the present study was to assess the intra- and inter-rater reliability of infrared image analysis of myofascial trigger points in the upper trapezius muscle. METHOD: A reliability study was conducted with 24 volunteers of both genders (23 females) between 18 and 30 years of age (22.12±2.54), all having cervical pain and presence of active myofascial trigger point in the upper trapezius muscle. Two trained examiners performed analysis of point, line, and area of the infrared images at two different periods with a 1-week interval. The intra-class correlation coefficient (ICC2,1) was used to assess the intra- and inter-rater reliability. RESULTS: With regard to the intra-rater reliability, ICC values were between 0.591 and 0.993, with temperatures between 0.13 and 1.57 °C for values of standard error of measurement (SEM) and between 0.36 and 4.35 °C for the minimal detectable change (MDC). For the inter-rater reliability, ICC ranged from 0.615 to 0.918, with temperatures between 0.43 and 1.22 °C for the SEM and between 1.19 and 3.38 °C for the MDC. CONCLUSION: The methods of infrared image analyses of myofascial trigger points in the upper trapezius muscle employed in the present study are suitable for clinical and research practices. .

Intra and inter-rater reliability of infrared image analysis of masticatory and upper trapezius muscles in women with and without temporomandibular disorder / Confiabilidade intra e interexaminador da análise de imagens infravermelhas dos músculos mastigatórios e trapézio superior em mulheres com e sem disfunção temporomandibular

BACKGROUND: Infrared thermography is an aid tool that can be used to evaluate several pathologies given its efficiency in analyzing the distribution of skin surface temperature. OBJECTIVES: To propose two forms of infrared image analysis of the masticatory and upper trapezius muscles, and to determine the intra and inter-rater reliability of both forms of analysis. METHOD: Infrared images of masticatory and upper trapezius muscles of 64 female volunteers with and without temporomandibular disorder (TMD) were collected. Two raters performed the infrared image analysis, which occurred in two ways: temperature measurement of the muscle length and in central portion of the muscle. The Intraclass Correlation Coefficient (ICC) was used to determine the intra and inter-rater reliability. RESULTS: The ICC showed excellent intra and inter-rater values for both measurements: temperature measurement of the muscle length (TMD group, intra-rater, ICC ranged from 0.996 to 0.999, inter-rater, ICC ranged from 0.992 to 0.999; control group, intra-rater, ICC ranged from 0.993 to 0.998, inter-rater, ICC ranged from 0.990 to 0.998), and temperature measurement of the central portion of the muscle (TMD group, intra-rater, ICC ranged from 0.981 to 0.998, inter-rater, ICC ranged from 0.971 to 0.998; control group, intra-rater, ICC ranged from 0.887 to 0.996, inter-rater, ICC ranged from 0.852 to 0.996). CONCLUSION: The results indicated that temperature measurements of the masticatory and upper trapezius muscles carried out by the analysis of the muscle length and central portion yielded excellent intra and inter-rater reliability.

CONTEXTUALIZAÇÃO: A termografia infravermelha vem sendo utilizada como instrumento auxiliar na avaliação de patologias diversas, dada a sua eficiência na investigação da distribuição da temperatura superficial cutânea. OBJETIVOS: Propor duas formas de análise das imagens infravermelhas dos músculos mastigatórios e trapézio superior e determinar a confiabilidade intra e interexaminador dessas duas formas de análise. MÉTODO: Foram coletadas imagens infravermelhas dos músculos mastigatórios e trapézio superior de 64 voluntárias do gênero feminino, com e sem disfunção temporomandibular (DTM). A análise das imagens infravermelhas ocorreu de duas formas: mensuração da temperatura da extensão do músculo e do centro do músculo, sendo realizada por dois examinadores. A confiabilidade intra e interexaminador foi verificada por meio do Coeficiente de Correlação Intraclasse (CCI). RESULTADOS: Os valores do CCI intra e interexaminador foram considerados excelentes em ambas as avaliações: análises da extensão do músculo (grupo DTM, intraexaminador, CCI variou de 0,996 a 0,999, interexaminador, CCI variou de 0,992 a 0,999; grupo controle, intraexaminador, CCI variou de 0,993 a 0,998, interexaminador, CCI variou de 0,990 a 0,998) e análise do centro do músculo (grupo DTM, intraexaminador, CCI variou de 0,981 a 0,998, interexaminador, CCI variou de 0,971 a 0,998; grupo controle, intraexaminador, CCI variou de 0,887 a 0,996, interexaminador, CCI variou de 0,852 a 0,996). CONCLUSÃO: O estudo evidenciou que a mensuração da temperatura dos músculos mastigatórios e trapézio superior, realizada por meio da análise da extensão e do centro do músculo, apresentou excelente confiabilidade intra e interexaminador.