title: A radiographic analysis of the influence of initial neck posture on cervical segmental movement at end-range extension in asymptomatic subjects.
abstract: In the management of neck pain disorders, McKenzie recommends performing neck extension exercises from a fully neck retracted position in order to achieve a maximum range of lower cervical extension. However, no study has investigated the impact of pre-positioning the neck prior to the extension exercise. This study compared end-range sagittal cervical segmental rotation and translation from three starting positions: the neck in neutral (Ex), retraction (Ret-Ex) and protraction (Pro-Ex). Twenty asymptomatic healthy volunteers were recruited. Lateral radiographs were taken in neutral and at each of the three end-range extension positions and differences in sagittal rotation angles and translation from the neck neutral posture were calculated at each segment. The results indicated that there was a significant difference in the pattern of the sagittal segmental rotation (P < 0.001) but no difference in summed rotations (total extension) between the three conditions (P > 0.05). Pro-Ex generated significantly (P < 0.05) greater extension range at C1-2 and Ret-Ex produced significantly (P < 0.05) greater extension range at C6-7 than alternate conditions. In contrast, there was no significant difference in segmental translation values between the three conditions (P > 0.05). These results indicate initial neck positions can influence cervical segmental extension range at C1-2 and C6-7.
authors: Division of Physiotherapy, School of Health and Rehabilitation Science, The University of Queensland, Brisbane, Queensland 4072, Australia. hiroshi.takasaki@uqconnect.edu.au
authors: Hiroshi
authors: H
authors: Takasaki
authors: Toby
authors: T
authors: Hall
authors: Shouta
authors: S
authors: Kaneko
authors: Yoshikazu
authors: Y
authors: Ikemoto
authors: Gwendolen
authors: G
authors: Jull
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D009333:Neck; D019547:Neck Pain / Q000000981:diagnostic imaging* / Q000534:rehabilitation; D011187:Posture; D011859:Radiography; D015203:Reproducibility of Results; D012399:Rotation