Table 1 Inclusion and exclusion criteria

Inclusion criteria

• Adults (20–70 years of age)

• Females

• With or without neck pain

Exclusion criteria

• Diagnosis of recent trauma, spinal surgery, fractures or structural pathologies in the area of interest, to ensure the right anatomical landmarks on the ultrasound image during the ultrasound procedure of identifying the muscle

• Not able to comply with the examination procedure

• If for whatever reason anatomical landmarks and muscle borders could not be clearly enough identified on the ultrasound images for analysis