A randomized, comparative trial: does pillow type alter cervico-thoracic spinal posture when side lying?

BACKGROUND: Many patients ask for advice about choosing a pillow. This research was undertaken to determine if pillow type alters cervico-thoracic spine position when resting in the side-lying position. AIM: To investigate the effect of different pillow shape and content on the slope of cervico-thoracic spine segments when side lying. MATERIALS AND METHODS: The study was a randomized blinded comparative trial set in a laboratory that replicated a bedroom. The subjects were side sleepers aged over 18 years. Exclusion criteria were history of surgery to the cervico-thoracic spine, an injury or accident to the cervico-thoracic spine in the preceding year, or currently receiving treatment for neck symptoms. Each participant rested in a standardized side-lying position for 10 minutes on each of the trial pillows: regular shaped polyester, foam, feather, and latex pillows, and a contour shaped foam pillow. Reflective markers were placed on external occipital protuberance (EOP), C2, C4, C7, and T3, and digital images were recorded of subjects at 0 and 10 minutes on each pillow. Images were digitized using each reflective marker and the slope of each spinal segment calculated. Univariate analysis of variance models were used to investigate slope differences between pillows at 0 and 10 minutes. Significance was established at P < 0.01 to take account of chance effects from repeated measures and multiple comparisons. RESULTS: At 0 and 10 minutes, the EOP-C2, C2-C4, and C4-C7 segmental slopes were significantly different across all pillows. Significant differences were identified when comparing the feather pillow with the latex, regular and contour foam pillows, and when comparing the polyester and foam contour pillows. The regular and contour foam pillows produced similar slopes at all spinal segments. CONCLUSION: Cervico-thoracic spinal segment slope alters significantly when people change from a foam, latex, or polyester pillow to a feather pillow and vice versa. The shape of a foam pillow (contour versus regular shape) does not significantly alter cervico-thoracic spinal segment slope.