Correction: Examining relationships between sleep posture, waking spinal symptoms and quality of sleep: A cross sectional study.

[This corrects the article DOI: 10.1371/journal.pone.0260582.].

Examining relationships between sleep posture, waking spinal symptoms and quality of sleep: A cross sectional study.

INTRODUCTION: Research with a focus on sleep posture has been conducted in association with sleep pathologies such as insomnia and positional obstructive sleep apnoea. Research examining the potential role sleep posture may have on waking spinal symptoms and quality of sleep is however limited. The aims of this research were to compare sleep posture and sleep quality in participants with and without waking spinal symptoms. METHODS: Fifty-three participants (36 female) were, based on symptoms, allocated to one of three groups; Control (n = 20, 16 female), Cervical (n = 13, 10 female) and Lumbar (n = 20, 10 female). Participants completed an online survey to collect general information and patient reported outcomes and were videoed over two consecutive nights to determine sleep posture using a validated classification system including intermediate sleep postures. RESULTS: Participants in the symptomatic groups also reported a lower sleep quality than the Control group. Compared to Control group participants, those in the Cervical group had more frequent posture changes (mean (SD); 18.3(6.5) versus 23.6(6.6)), spent more time in undesirable/provocative sleep postures (median IQR; 83.8(16.4,105.2) versus 185.1(118.0,251.8)) minutes and had more long periods of immobility in a provocative posture, (median IQR: 0.5(0.0,1.5) versus 2.0 (1.5,4.0)). There were no significant differences between the Control and Lumbar groups in the number of posture changes (18.3(6.5) versus 22.9(9.1)) or the time spent in provocative sleep postures (0.5(0.0,1.5) versus 1.5(1.5,3.4)) minutes. DISCUSSION: This is the first study using a validated objective measure of sleep posture to compare symptomatic and Control group participants sleeping in their home environment. In general, participants with waking spinal symptoms spent more time in provocative sleep postures, and experienced poorer sleep quality.

Identifying relationships between sleep posture and non-specific spinal symptoms in adults: A scoping review.

OBJECTIVES: The objectives of this scoping review were to identify (1) study designs and participant populations, (2) types of specific methodology and (3) common results, conclusions and recommendations from the body of evidence regarding our research question; is there a relationship between sleep posture and spinal symptoms. DESIGN: Scoping review. DATA SOURCES: PEDro, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, Medline, ProQuest, PsycINFO, SportDISCUS and grey literature from inception to 10 April 2018. DATA SELECTION: Using a modified Arksey and O'Malley framework, all English language studies in humans that met eligibility criteria using key search terms associated with sleep posture and spinal symptoms were included. DATA EXTRACTION: Data were independently extracted by two reviewers and mapped to describe the current state of the literature. Articles meeting the search criteria were critically appraised using the Downs and Black checklist. RESULTS: From 4186 articles, four articles were identified, of which three were epidemiological and one interventional. All studies examined three or more sleep postures, all measured sleep posture using self-report and one study also used infrared cameras. Two studies examined symptoms arising from the lumbar spine, one the cervical spine and one the whole spine. Waking pain and stiffness were the most common symptoms explored and side lying was generally protective against spinal symptoms. CONCLUSIONS: This scoping review highlights the importance of evaluating sleep posture with respect to waking symptoms and has provided preliminary information regarding relationships between sleep posture and spinal symptoms. However, there were not enough high-quality studies to adequately answer our research question. It is recommended future research consider group sizes and population characteristics to achieve research goals, that a validated measure be used to assess sleep posture, that characteristics and location of spinal symptoms are clearly defined and that the side lying posture is subclassified.

Examining the validity and reliability of a portable sleep posture assessment protocol, using infrared cameras, under a variety of light and bed cover situations in the home environment.

BACKGROUND: Spinal symptoms of pain and stiffness on waking have been linked to sleep posture. Sleep posture is commonly classified as supine, side lying and prone. It is clinically postulated that sleeping postures with sustained end of range rotation and extension may influence pain sensitive spinal tissues. However, the lack of a valid and reliable method of assessing sleep posture, means clinicians are unable to provide corrective advice based upon evidenced based research. OBJECTIVE: To determine the validity and reliability of a sleep posture recording protocol in the home environment. METHOD: Twenty health professionals viewed a pre-recorded video recording of randomised sleep postures under natural and infrared light situations, with a variety of bed coverings, to represent the habitual environment. Sleep postures were classified into six categories including two intermediate postures (supported side lying and provocative side lying). Viewing was repeated after two days. RESULTS: Intra-and inter-rater reliability were excellent; Cohen's Kappa = .93 (95% CI 0.80 to 1.0) and Fleiss Kappa = 0.83 (95% CI 0.82 to 0.84) respectively. Validity, determined as concordance between the health professionals' classifications and the known postures, was also excellent Cohen's Kappa = .91 (95% CI 0.77 to 1.0). CONCLUSIONS: Reliable and valid assessment of sleep posture, including intermediate postures, could be achieved using low cost, portable, infrared video recording equipment, under a variety of lighting conditions and a variety of bed cover situations typical of the home environment.