The effect of various pillow types on cervico-thoracic and forward head posture in young adults

Abstract

Correct neck support is required during sleep to align the spine and maintain neutral posture, and to immobilise the joints in the neck which would allow the cervical paraspinal muscles to relax (De Laittre, 1974; Ambrogio et al., 1998; Erfanian et al., 1998). Poor spinal posture during sleep however, has been hypothesized to result in lateral bending and uneven loading on the intervertebral discs and cervical facet joints, and compression of pain-sensitive structures in the neck (Leilnahari et al., 2011). The pillow is a significant contributing factor to sleep quality and the development of symptoms on waking (Gordon et al., 2011). This should theoretically reduce pressure on the pain-sensitive structures and allow the intervertebral discs to be unloaded and rehydrated (Leilnahari et al., 2011). Aim: To determine and compare the effect of the Simmons’ Beautyrest pillow, a polyester foam pillow, a latex pillow, and no pillow, on cervico-thoracic and forward head posture in the supine and recumbent supine positions in asymptomatic individuals. Methods: Forty asymptomatic subjects between the ages of 20 and 30 years were recruited using convenience sampling. The study was a double-blinded comparative investigation where all participants underwent a case history, physical examination and an orthopaedic examination of the cervical spine. Thereafter, digital photographic images of the participants lying without a pillow and on three different pillows (Simmons Beautyrest® pillow, a polyester foam pillow and a latex pillow) in the supine and recumbent positions were captured. These images were then uploaded onto a computer, and using the linear co-ordinates of each anatomical landmark (which was determined by the researcher using CorelDraw Graphics Suite 12), the cervico-thoracic and craniocervical postures were determined. The cervico-thoracic posture was determined by calculating the gradients of the intersegmental slopes, relative to the horizontal plane, using the formula (y2 − y1)/(x2 − x1). The craniocervical posture was determined by calculating the craniocervical angle. This angle was determined by constructing lines between the anatomical landmarks and measuring the angle produced at C7. At the end of the objective data collection, participants were asked verbally which pillow they found most comfortable. All data was collected by the researcher. Statistical analysis was done using IBM SPSS version 21.0. Repeated measures ANOVA test was used to compare the mean slope measurements in the four conditions. Inferential techniques included Wilcoxon Signed-Rank test and t-tests. A p-value of < 0.05 indicated statistical significance. iv Results: The mean (± SD) age of the participants was 24.3 (± 2.57) years. In terms of pillow preference, 15 participants preferred the latex pillow, 8 preferred the polyester pillow and 17 preferred the Simmons Beautyrest® pillow. In the recumbent position for the C2-EOP slope the latex and Simmons Beautyrest® pillows supported the neck in a similar manner (p= 0.480) and closer to neutral than no pillow and the latex pillow. For the C4-C2 and the C7-C4 slopes, the latex pillow produced the least extreme slope. For the T3-C7 slope, the polyester pillow produced the slope closest to neutral. Overall, for the entire cervical spine, the latex pillow produced the least extreme slopes, but at the cervico-thoracic junction, the polyester pillow produced the most neutral slope. In all segments, the condition without a pillow produced the most extreme slopes. When comparing the slopes themselves, it can be seen that the most extreme deviations from neutral occurred at the C2-EOP segment. The midcervical spine deviated least from neutral. In the supine position, there were no significant differences (p> 0.05) in the sagittal angular displacement between the pillows. Conclusion: The results of this study support the view that there is no one particular pillow that is better than the others for providing optimal support to the head and neck. Furthermore, practitioners should be aware that it is the craniocervical and cervico-thoracic slopes, which are determined with the patient in the recumbent position, that provide significant information regarding support provided by the pillow rather than the sagittal angular displacement assessed in the supine position.