Weakness and Imbalance of Neck Muscle Groups as Sources of ‎Chronic Neck Pain: ‎A Cross-Sectional Study

Purpose: This study aimed to investigate weakness and strength imbalances of the four principal neck muscle groups and their association with pain intensity in adults with chronic neck pain.

Materials and Methods: This cross-sectional study enrolled 29 patients (22 men, 7 women; aged 20–70 years) with chronic neck pain attending private physiotherapy clinics in Zawia, Libya. The strength of the cervical and capital flexor and extensor groups was graded using manual muscle testing (0–5 scale), and pain intensity was recorded on a 10-point visual analogue scale (VAS). One-sample t-tests compared each muscle group against the normal grade of 5, paired t-tests examined imbalances between and within muscle chains, and Pearson correlations related muscle strength to pain. The significance level was set at p < 0.05.

Results: All four muscle groups were significantly weaker than grade 5 (p < 0.001). The capital flexors were the weakest group (mean 2.62 ± 0.49). Significant imbalances were found between cervical flexors and capital flexors (p < 0.001), between capital flexors and capital extensors (p < 0.001), and between the anterior and posterior muscle chains (p < 0.001), whereas cervical flexors and extensors were equally affected. Pain intensity correlated significantly with cervical flexor strength (r = −0.455, p = 0.013), capital extensor strength (r = −0.406, p = 0.029), and the anterior (r = −0.400, p = 0.031) and posterior (r = −0.422, p = 0.022) chain strength.

Conclusion: Chronic neck pain is characterized by pronounced weakness of all neck muscle groups, a selective deficit of the capital flexors, and specific flexor–extensor imbalances. Weaker muscle groups track with higher pain intensity, supporting targeted strengthening of the deep flexors in rehabilitation. (Open J Biomed Res 2026;5:147-154)