The effect of different exercise programs on cervical flexor muscles dimensions in patients with chronic neck pain is yet to be shown. The objective of this study was to evaluate the effect of two exercise programs; craniocervical flexion (CCF) and cervical flexion (CF), on flexor muscles dimensions in patients with chronic neck pain. Following ethical approval, 60 patients were assigned at random to either a CCF group or a CF group. Patients in the CCF group were given CCF exercises and those in the CF group received CF exercises. All patients were given interventions for a period of ten weeks. Pain intensity and functional disability were assessed using numerical pain rate scale and neck disability index, respectively. Dimensions of longus colli (LC) and sternoclidomastoid (SCM) muscles were measured using ultrasonography (US). All measurements were taken prior to and following interventions. After intervention, the CCF group demonstrated a significant increase in LC muscle dimensions including cross sectional area, width and thickness compared with the CF group. A statistically significant increase was found on SCM thickness in the CF group. Following intervention, SCM thickness measurement in the CCF group showed no significant changes. Statistically significant reduction in pain intensity and disability were also found in both groups.
These findings showed that craniocervical flexion program which specifically recruiting deep cervical flexor muscles increased LC muscle dimension significantly and CF program as an endurance training program increased SCM thickness.