Assessment procedure
twitch, NDI, MTrPs, pain, neck disability, neck pain
After signing the consent form, subjects were screened for eligibility to participate. Their demographic data was then collected. It was important to us after screening for eligibility to apply clearing tests to exclude any red flags. We used the Sharp-Purser [When the subject was cleared, he/she was asked to place a mark on the VAS line to indicate the level of pain intensity. A ruler was then used to measure the distance from zero, and the recorded number was rounded to the nearest number. For example, a measure of 5.7 cm was rounded to 6 cm.Subjects’ functional status was evaluated using the neck disability index (NDI). The NDI is a widely used self-reported outcome measure that assesses functional limitations in patients with neck pain. It has 10 items answered on a 0–5 Likert scale for each item. The total raw score is 50 with higher scores indicating greater disability. Psychometric properties for the NDI are well established in the literature [The subjects were then assessed for the presence or absence of MTrPs. We used previously published criteria for evaluation. This includes the presence of a palpable taut band in a muscle, presence of a hypersensitive point in a taut band, a twitch in a muscle caused by palpation, referred pain produced as a result of compression on a tender point, and/ or presence of classical referred pain pattern. Four out of five findings classified the trigger point as latent, while the five findings classified the trigger point to be active [The pressure algometer (model: FPX 50, S/N: 2,010,600,173, JTECH Medical, Midvale, Utah, USA) was then applied perpendicular to the trigger point (Fig. 
Procedure used in the study. left: assessment of pain pressure threshold, center: application of instrument-assisted soft tissue mobilization (group A), right: manual soft tissue release (group B)