Correlation between craniovertebral angle in the sagittal plane and angles and indices measured in the frontal plane at the moment of inducing forward head posture.

Background: Forward head posture (FHP) is the most common malposition in the head and neck area. With the growing use of digital devices, the prevalence of FHP may be expected to increase dramatically. Thus far, FHP has been evaluated only in the sagittal plane.

Objective: The objective of this study was to measure angles and indices from anatomical landmarks in the frontal plane and determine the possible correlations between these variables and craniovertebral angle (CVA) as an index of FHP in the sagittal plane.

Methods: Fifty eight healthy individuals (29 men, 29 women) between 18 and 40 years old participated in this cross-sectional study. Participants were evaluated with an 8-camera motion analysis system. After markers were placed on predetermined landmarks, the participants were asked to maintain their head and neck in the neutral position for 5 seconds. Then participants induced FHP by flexing and lowering their head. The correlation between CVA and a set of angles and indices was calculated at the moment of FHP induction.

Results: A moderate correlation was observed between 3-D CVA and the angle formed between the sternum and both tragi for the whole sample and separately in both sexes. A moderate negative correlation was observed between 3-D CVA and height, weight, and BMI in women. A moderate negative correlation was observed between 3-D CVA and height, weight, BMI, and hours on digital devices in men.

Conclusions: Changes in CVA in the sagittal plane can be predicted from changes in the angle formed between the midpoint of the sternum and the left and right tragi in the frontal plane.