Relationship Between Headaches and Neck Pain Characteristics With Neck Muscle Strength

Objective: The purpose of this study was to assess the correlations between neck muscle strength and pain features, such as neck-related disability, neck pain frequency and intensity, and headache frequency in women with headache. Methods: Seventy women with migraine between 18 and 55 years of age diagnosed according to International Headache Society criteria were assessed. Participants provided clinical information regarding neck pain and headache. The Neck Disability Index was used to assess neck-related disability, and neck muscle strength was assessed via maximum voluntary contraction during flexion, extension, and lateral flexion with a handheld dynamometer. The correlation was verified with Spearman's correlation coefficient (rho). Multiple linear regression was performed to verify whether the clinical variables could predict the strength of neck muscles. All calculations were performed adopting a level of significance of 0.05. Results: Neck extensor strength was negatively correlated with all clinical variables (rho(range)= -.24 to -.32, p < .05); lateral flexor strength was negatively correlated with headache frequency, neck pain intensity, and neck-related disability (rho(range)= -.27 to -.39, p < .05); and flexor strength also correlated negatively with neck pain intensity and related disability (rho(r) = -.26 to -.29, p < .05). Headache frequency and neck pain intensity were identified as significant predictors of the strength variability in extension (R-2 = 0.16, p < .05) and in lateral flexion (R-2 = 0.18, p < .05). Conclusions: For the women with migraine in this study, correlations of headache and neck pain with neck muscle strength features were weakly to moderately negative. Headache frequency and neck pain intensity may influence a small proportion of the strength variability in extension and lateral flexion.