Tehran University of Medical Sciences Journal of Modern Rehabilitation 2538-385X 18 1 2024 01 01 106 113 Sedighe Sadat Naimi Physiotherapy Research Center, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Fateme Bokaee Department of Physiotherapy, School of Rehabilitation Sciences, Isfahan University of Medical Sciences, Isfahan, Iran. 2022 07 13 2022 11 21 Introduction: The skeletal muscle’s echo intensity (EI) is a measurement that can be used to assess the quality of the muscle and any muscle damage caused by training or activity. To determine its reliability, a limited number of studies have investigated the measurement of cervical muscles’ EI. This study determines whether the EI of the cervical muscles can be reliably quantified using the Adobe Photoshop software. Materials and Methods: The mean EI of the cervical muscles was measured using the standard histogram function of Adobe Photoshop CS6 in 20 healthy women. Results: The measurement of EI of cervical muscles using Adobe Photoshop CS6 is reliable in healthy women (intra-class coefficient >0.9). The values of the standard error of measurements of longus coli, sternocleidomastoid, levator scapula, semispinalis capitis, rectus capitis posterior, and oblique capitis superior muscles were 1.81, 2.09, 1.46, 2.02, 1.47 and 1.26, respectively. The values of the smallest detectable difference of longus coli, sternocleidomastoid, levator scapula, semispinalis capitis, rectus capitis posterior, and oblique capitis superior muscles were 7.11, 8.22, 5.74, 7.93, 5.79, and 4.97, respectively.  Conclusion: Assessing the EI of the cervical muscles with Adobe Photoshop software is a viable method to determine the quality of the muscles. https://jmr.tums.ac.ir/index.php/jmr/article/view/704