Study design: A repeated measures observational study.
Objective: To investigate change in sagittal alignment of head and neck posture in response to adjustments of an office chair with and without a lumbar roll in situ.
Summary of background data: Forward head posture has been identified as a risk factor for neck pain, and there is evidence to show that ergonomic correction in sitting may reduce the incidence of pain. The effect placement of a lumbar roll has on cervical spine posture has not been previously investigated experimentally but rather, is assumed to have a positive influence on head and neck posture.
Methods: Thirty healthy male participants (18-30 years) were photographed while registered in the natural head resting position in each of 4 sitting positions with and without a lumbar roll in situ. Two positions incorporated adjustments to the back rest and 1 to the seat pan of the office chair. The craniovertebral (CV) angle, as a determinant of head and neck posture was measured from the set of digitized photographs obtained for each participant. Comparisons between the CV angle in all postural registrations were made using a mixed model analysis adjusted for multiple comparisons.
Results: Of the positions examined, significant differences in the mean CV angles were found with the backrest of the chair at 100 degrees and at 110 degrees (P < 0.001). With the lumbar roll in situ and the backrest position at 110 degrees , there was a significant increase in the mean CV compared with the angle without the lumbar roll in situ (2.32 degrees , 95% confidence interval: 1.31-3.33; P < 0.001).
Conclusion: The degree of angulation of the backrest support of an office chair plus the addition of lumbar roll support are the 2 most important factors to be taken into account when considering seating factors likely to favorably change head and neck postural alignment, at least in asymptomatic subjects.