title: Associated sagittal spinal movements in performance of head pro- and retraction in healthy women: a kinematic analysis.
abstract: Sagittal head excursions are frequently used as diagnostic and treatment tools by physiotherapists. Retractions are performed to promote good head-on-body orientation. This study examined the regional contribution of spinal movements to head pro- and retraction in addition to the effect of a more or less restrained sitting position in healthy women. Fourteen healthy women performed seven sagittal head excursions in a more or less restrained sitting position, during which time their kinematic response was measured with an optoelectronic system. Total anterior/posterior head excursion was smaller (P=0.005) in the more restrained sitting position. In both sitting positions, approximately 60% of the total anterior/posterior head excursion originated from the cervical spine, almost 30% from the cervicothoracic spine C7-T4, and approximately 10% from thoracic regions down to T12. Middle thoracic vertical displacement was smaller (p=0.005) in the more restrained sitting position. A high correlation was found between total head excursion and the cervicothoracic unit displacements in both sitting positions (r=0.79, r=0.85, respectively). In each sitting position, the craniovertebral angle, and the tragus-C7-horizontal line decreased in protraction. Movements in the thoracic region contributed to the total head excursion. Therefore, clinicians should recognize the thoracic contribution to sagittal head excursion when using pro- and retraction as a diagnostic and treatment tool.
authors.affiliation: Högsby sjukgymnastik, Högsby, Sweden.
authors.forename: P Rune
authors.initials: PR
authors.lastname: Persson
authors.forename: Helga
authors.initials: H
authors.lastname: Hirschfeld
authors.forename: Lena
authors.initials: L
authors.lastname: Nilsson-Wikmar
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D011187:Posture / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012680:Sensitivity and Specificity; D013131:Spine / Q000502:physiology; D013904:Thoracic Vertebrae / Q000502:physiology*