Correlations between and Absolute Rotation Angle, Anterior Weight Bearing, Range of Flexion and Extension Motion in Cervical Herniated Nucleus Pulposus

Abstract

[Purpose] We attempted to examine the range of motion (rotation, flexion and extension) of the neck and forward head posture in patients with a cervical herniated nucleus pulposus (C-HNP) and in normal persons through radiometry; and examined the correlations between the ranges of these motions and C-HNP. [Subjects] The study subjects were 15 patients with C-HNP at level 5 or 6 (C5-6, (males=5, females=10) and 15 normal persons (males=5, females=10). [Methods] We analyzed the degree of cervical lordosis of patients with C-HNP at C5-6 and normal adults and compared them using radiographs of their lateral views. We observed the absolute rotation angles (ARA), anterior weight bearings (AWB) and ranges of flexion and extension motion (RFEM). [Results] The results indicated that as ARA increased, AWB decreased and RFEM increased. In particular, we confirmed that as AWB increased, RFEM decreased. [Conclusion] This study identified a remarkably decreased range of cervical motion in patients with C-HNP compared to normal persons, along with misalignments of the cervical spine due to from increased forward head posture.