These two papers report on findings from congruent yet separate studies regarding the performance of people's own pillow. Data for these papers was extracted from three previously published studies undertaken in the same South African adult-aged [18+ years] community by the same researchers:1. Study 1: a telephone survey administering a standard questionnaire, and 2. 18 months later, two concurrent experimental studies using five test pillows compared with subjects' "own" pillow: Study 2: a pillow field trial of waking symptoms, pillow comfort and sleep quality, and Study 3: a photographic study of changes in cervical posture in side lying.
All studies received ethics approvals from the University of South Australian HumanResearch Ethics Committee.Study 1 was a telephone survey of 812 randomly-selected participants from the local telephone directory. This study described and correlated "own" pillow type, use, age and performance, subjects' sleeping habits, waking symptoms, sleep quality, and pillow comfort.Subjects were asked to reflect on a "usual, recent" week when they provided this information."Own" pillow use was associated with self-reported waking symptoms [headache, neck pain, stiff neck, and scapula-arm pain] for approximately 46 percent subjects. Five pillow types were commonly used [polyester, foam regular, foam contour, feather, and latex]. In the year preceding the survey, 26.2 percent subjects had purchased a new pillow. The mean age of pillows in this study was 58.9 months [standard deviation [SD] 74.4 months]. New pillows were purchased for many reasons including poor support and comfort, neck discomfort, and compromised hygiene. This study did not validate subjects' self-report of "own" pillow type, shape, or age, nor measure waking symptom intensity. [comprising 61 subjects from the telephone survey and 45 recruits from advertisements] using a randomized controlled block-design. Differences were assessed in the effect of subjects' "own" pillow, and the test pillows, on retiring and waking symptoms [pain, stiffness, headache, and scapula-arm pain]. Where possible, subject's "own" pillow was inspected for shape, condition and content. Study 3 was a posture study in which 95 subjects [comprising 81 subjects from Study 2 and 14 additional recruits from advertisements] were photographed in a standardized side-lying position on each of the trial pillows, and "own" pillow, at 0 minutes and 10 minutes later. Short-term change in cervical spine posture on each pillow was compared. Cervico-thoracic posture was measured by digitising the x,y coordinates of five anatomical points [spinous processes of C2, C4, C7, and T3, and the external occipital protuberance], and calculating within-and between-point change in position over time.Subject's "own" pillow depth and the depth of the trial pillows were measured, to allow consideration of pillow performance with respect to altered pillow depth, by placing the pillow on a horizontal table surface and putting a horizontally levelled piece of masonite on top o...