Craniocervical posture determination by photogrammetry in adults: comparison of two cervical palpation methods

Abstract

Introduction: Non-specific neck pain is often associated to craniocervical posture. Photogrammetry accurately and reliably assesses the static body posture, but the effect of palpation methods for locating anatomical landmarks in photogrammetry remains uninvestigated. Objective: This study compared the craniocervical posture assessed by photogrammetry using two distinct palpation methods for locating the spinous process of the seventh cervical vertebra (C7SP). Methods: This cross-sectional study was conducted in two phases. In phase I (n=42), the assessor’s accuracy to locate the spinous process of the C7SP using the flexion-extension and the modified thorax-rib static methods was compared to radiography. In phase II (n=68), the craniocervical posture was analyzed using photogrammetry after palpation using the two methods. Neck pain intensity and disability were also determined. Results: The accuracy for locating the C7SP was higher using the modified thorax-rib static method (67%, 95%CI=[55; 79]) compared to flexion-extension method (38%, 95%CI=[26; 50], P=0.016). Lower values of craniocervical angle were obtained with flexionextension method than the modified thorax-rib static method (MD: -1.1, 95%CI=[-1.6; -0.6], P<0.001). However, both palpation methods resulted in similar classification of the participants as with or with-out forward head posture (P=0.096). Weak correlations were observed between the craniocervical angle and neck pain intensity (r=-0.088 and -0.099, respectively) and disability (r=-0.231 and -0.249, respectively). Conclusion: Photogrammetry assessment of the craniocervical posture using two palpation methods with distinct accuracy results in different craniocervical angles but similar forward head posture classification in adults with mild neck pain and disability. Craniocervical posture was weakly correlated with neck pain intensity or disability.