Correlation between the Photographic Cranial Angles and Radiographic Cervical Spine Alignment

Abstract

The cranial vertical angle (CVA) and cranial rotation angle (CRA) are used in clinical settings because they can be measured on lateral photographs of the head and neck. We aimed to clarify the relationship between CVA and CRA photographic measurements and radiographic cervical spine alignment. Twenty-six healthy volunteers were recruited for this study. Lateral photographs and cervical spine radiographs were obtained in the sitting position. The CVA and CRA were measured using lateral photographs of the head and neck. The C2-7 sagittal vertical axis (SVA), cervical lordosis (C2-7), and occipito-C2 lordosis (O-C2) were measured using radiographic imaging as a standard method of evaluating cervical spine alignment. Correlations between the CVA and CRA on photographs and cervical spine alignment on radiographs were analyzed. The CVA and SVA were significantly negatively correlated (ρ = −0.51; p < 0.05). Significant positive correlations were found between CVA and C2-7 (ρ = 0.59; p < 0.01) and between CRA and O-C2 (ρ = 0.65; p < 0.01). Evaluating the CVA and CRA on photographs may be useful for ascertaining head and neck alignment in the mid-lower and upper parts of the sagittal plane.

Holistic Approach for Markerless Head-Neck Posture Assessment

“…The results of other studies show that the values for the CV angle range from 57.70° to 42.26° (Table 4). The average angle of 53.90° of the current study is in the same order of magnitude as Kawasaki [16], Niekerk [20] and Vasavada [25]. It should be noted that the previous studies analyzing the CV angle had a significantly smaller number of adult participants.…”

“…Smaller CVA indicates greater protraction of the head, and larger angles are more representative of 'ideal' sagittal plane head and neck alignment [9]. Often this angle is analyzed in a neutral seated posture and standing posture [10][11][12][13][14][15][16][17]. Another angle that is determined in a neutral seated posture is the head tilt angle (HTA).…”

Characteristics of head and neck alignment and function of deep cervical flexor muscles in patients with nonspecific neck pain

“…The CRA is reduced by flexion of the upper cervical spine, while the CVA is increased by extension of the middle-lower cervical spine; these combined movements lead to a retracted head posture. 33 Collectively, these findings suggest that patients with NSNP have a larger degree of flexion of the upper cervical spine and extension of the middle-lower cervical spine in the corrected head position from the natural head posture, showing a hypercorrected head posture compared to control groups.…”

“…A study involving measurement of the head and neck alignment in the natural head posture in healthy participants showed the CRA was 148.9 (8.7)° and the CVA was 50.9 (3.8)°. 33 A study measuring natural head posture using a digital camera in healthy participants reported the CVA as 50.4 ± 5.2°. 34 In the corrected head and neck alignment (CRA: 149.7±5.5°, CVA: 50.6±4.5°) of the NSNP group in this study, the CRA was smaller and CVA larger than those in previously reported healthy data.…”

Efficacy of ultrasound therapy with neck retraction exercises vs. ultrasound therapy with deep cervical flexor training for excessive screen time users: a pilot randomized controlled study

“…Reflective adhesive dots, 8 mm in diameter, were posted on the C7 spinous processes and the tragus of the ear. The CVA was calculated by measuring the angle formed by the line connecting C7 with the tragus of the ear and the horizontal line 17 ) .…”