Measuring Craniovertebral Angle Reference Values in Adults Using Kinovea Software

The clinical examination of patients with cervical spine pathology includes measures of posture, mobility, strength, and stability. The forward head position as measured by craniovertebral angle (CVA) has been suggested as a risk factor for cervical spine pathology. The purpose of this study was to describe CVA reference values in healthy adults and assess the relationship with age and sex. This prospective cross-sectional observational study measured the CVA in 122 healthy adults using digital analysis of a lateral view photograph. To facilitate this analysis, a marker was placed at the level of the C7 vertebra, with the tragus of the ear visible in the photograph. The CVA was measured using Kinovea 0.8.15 software, where the CVA was calculated using the intersection of a horizontal line with a line joining the spinous process of C7 and the tragus of the ear. Mean CVA values were 48.76° (6.77) across all participants, 50.07° (6.63) for females, and 47.46° (6.71) for males. Linear regression analysis indicated significant relationships with age and with sex. The study established CVA reference values in healthy adults and identified a significant difference in head position between males and females and a 1.6° decrease in CVA per decade of increased age.