ultrasonography method of deepcervical muscles and thickness measurement reliability incervicogenic headache and healthy subjects: a pilot study

Introduction: in cervicogenic headache (cgh), motor control of muscles is impaired anddeep upper neck muscles (extensor and flexor muscles) become atrophied. in this research,thickness measurement of longus capitis (lcap), rectus capitis posterior major (rcpm),and obliquus capitis superior (ocs) muscles were conducted and intra-rater reliability of thethickness measurement of these muscles was assessed in cgh and healthy subjects.materials and methods: twenty subjects, including 10 healthy subjects (19-32 years old) and10 cgh patients (20-35 years old) participated in this study. lcap thickness was measured atthe level of c3-c4 in the supine position and posterior muscles (rcpm and ocs) thicknessat the c1-c2 level in the sitting position. all ultrasound images were captured by a linearprobe with a 50-mm footprint in b mode option and frequency range of 9-12 hz. intraclasscorrelation coefficients (icc), standard error of measurement (sem), and the smallestdetectable difference (sdd) were calculated for data analysis.results: the icc for thickness measurement of lcap was from 0.70 to 0.91 (good toexcellent), for rcpm thickness was from 0.69 to 0.94 and for ocs muscle thickness wasfrom 0.87 to 0.98. sem values for lcap were between 0.08 and 0.25 and the sdd valuesbetween 0.22 and 0.71. sem values for rcpm were between 0.22 and 0.43 and these valueswere reported for ocs muscle between 0.19 and 0.45.conclusion: the results indicated that the presented position and the level of ultrasonographyin this study are appropriate and ultrasound is a reliable tool to measure the deep upper neckmuscle thickness in cgh and healthy subjects.