An investigation of head and neck posture as a possible cause of headache

Headache is a common clinical problem with 46% of the general population suffering headaches at some time in any one year. Biological and clinical evidence suggest that the neck is associated with headache. However, the signs and symptoms of so called ‘cervicogenic’ headache overlap with other common types of headaches complicating its diagnosis. The objective of this pilot study was to test whether a sustained altered head and neck posture induces headache. The aims of the study were to: i) establish the intra- examiner reliability of using the Vicon 3D motion capturing system, to measure spatial coordinates of the head, upper neck (C2) and lower neck (VP) when seated at a computer workstation; ii) determine whether adopting a sustained extended head and neck posture to view a computer screen induces headaches in headache-free adults. The head and neck position of five adult humans were recorded on two separate occasions using a ‘Vicon’ system while they adopted either a ‘relaxed’ or ‘extended’ head and neck posture for up to 20 minutes. The intra-examiner reliability of using the Vicon system to measure head, C2 and VP position was strongest in the sagittal plane (Head to VP in Z-axis), with a ‘poor’ to ‘moderate’ correlation (Spearman’s ranged from –0.204 to 0.547) and a minimal detectable difference of 3.3° ± 0.5° (median ± 95% CI). Five minutes of the ‘extended’ head and neck posture precipitated neck pain in all participants with an intensity rating of 13/100 ± 6.5/100 (median ± 95% CI), and head pain with an intensity of 10/100 ± 5.9/100 (median ± 95% CI) in most (3/5) participants. This pilot study demonstrated that sustained extended head and neck posture may cause headache in headache-free persons. A suitably powered randomised controlled trial is necessary to formally test this pilot study finding.