How reliable is measurement of posture during sleep: real-world measurement of body posture and movement during sleep using accelerometers

Abstract Objective Understanding sleeping behaviours could improve prevention and treatment of sleep problems and associated health conditions. This study aimed to evaluate a method to assess body posture and movement during sleep using trunk-worn accelerometers for 28 days. Approach Participants (50 adults with low back pain (66% female); aged 32(±9) years) wore two activPAL-micro sensors (thigh, trunk) during their normal daily life for 28 consecutive days. Parameters related to body posture (e.g., time spent lying supine or prone) and movement (e.g., number of turns) during sleep were calculated for each night. Average values for each parameter were identified for different periods, the Spearman-Brown Prophecy Formula was used to estimate the minimum number of nights required to obtain a reliable estimate of each parameter, and repeatability of measures between different weeks was calculated. Main Results Participants spent 8.1(±0.8) hours asleep and most time (44%) was spent in a supine posture. The minimum number of nights required for reliable estimates varied between sleep parameters, range 4-21 nights. The most stable parameters (i.e., requiring less than seven nights) were “average activity”, “no. of turns”, “time spent prone”, and “posture changes in the first hour”. Some measures differed substantially between weeks. Significance Most sleep parameters related to body posture and movement require a week or more of monitoring to provide reliable estimates of behaviour over one month. Notably, one week may not reflect behaviour in another week, and the time varying nature of sleep needs to be considered.

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460 DO PATIENTS WITH LOW BACK PAIN PRESENT AN ALTERED BODY POSTURE?

European Journal of Pain ◽

10.1016/s1090-3801(09)60463-8 ◽

2009 ◽

Vol 13 (S1) ◽

Cited By ~ 1

Author(s):

A. Ljutow

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Body Posture ◽

Low Back

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Influence of sleep problems and co-occurring musculoskeletal pain on long-term prognosis of chronic low back pain: the HUNT Study

Journal of Epidemiology & Community Health ◽

10.1136/jech-2019-212734 ◽

2019 ◽

Vol 74 (3) ◽

pp. 283-289 ◽

Cited By ~ 1

Author(s):

Eivind Schjelderup Skarpsno ◽

Paul Jarle Mork ◽

Tom Ivar Lund Nilsen ◽

Anne Lovise Nordstoga

Keyword(s):

Chronic Pain ◽

Low Back Pain ◽

Back Pain ◽

Musculoskeletal Pain ◽

Chronic Low Back Pain ◽

Sleep Problems ◽

Low Back ◽

Hunt Study ◽

Long Term Prognosis

BackgroundWe investigated the influence of sleeplessness and number of insomnia symptoms on the probability of recovery from chronic low back pain (LBP), and the possible interplay between sleeplessness and co-occurring musculoskeletal pain on this association.MethodsThe study comprised data on 3712 women and 2488 men in the Norwegian HUNT study who reported chronic LBP at baseline in 1995–1997. A modified Poisson regression model was used to calculate adjusted risk ratios (RRs) for the probability of recovery from chronic LBP at follow-up in 2006–2008, associated with sleep problems and co-occurring musculoskeletal pain at baseline.ResultsCompared with persons without sleeplessness, persons who often/always experienced sleeplessness had a lower probability of recovery from chronic LBP (RR 0.65, 95% CI 0.57 to 0.74 in women and RR 0.81, 95% CI 0.69 to 0.95 in men). Although there was no clear evidence of statistical interaction between sleeplessness and co-occurring musculoskeletal pain, women and men who often/always experienced sleeplessness and had ≥5 additional chronic pain sites had RRs of recovery of 0.40 (95% CI 0.33 to 0.48) and 0.59 (95% CI 0.45 to 0.78), respectively, compared with persons without sleeplessness and 1–2 chronic pain sites.ConclusionThese findings suggest that preventing or reducing sleep problems among people with chronic LBP may have the potential of improving the long-term prognosis of this condition, also among those with several additional pain sites.

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An optimal control approach to manpower planning problem

Mathematical Problems in Engineering ◽

10.1155/s1024123x01001594 ◽

2001 ◽

Vol 7 (2) ◽

pp. 155-175 ◽

Cited By ~ 6

Author(s):

H. W. J. Lee ◽

X. Q. Cai ◽

K. L. Teo

Keyword(s):

Optimal Control ◽

Numerical Scheme ◽

Manpower Planning ◽

Planning Problem ◽

Time Varying ◽

Control Approach ◽

Different Types ◽

Minimum Number ◽

Varying Demand ◽

Optimal Control Approach

A manpower planning problem is studied in this paper. The model includes scheduling different types of workers over different tasks, employing and terminating different types of workers, and assigning different types of workers to various trainning programmes. The aim is to find an optimal way to do all these while keeping the time-varying demand for minimum number of workers working on each different tasks satisfied. The problem is posed as an optimal discrete-valued control problem in discrete time. A novel numerical scheme is proposed to solve the problem, and an illustrative example is provided.

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Omnidirectional Static Walking of a Quadruped Robot on a Slope

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2006.p0051 ◽

2006 ◽

Vol 18 (1) ◽

pp. 51-58

Author(s):

Lei Zhang ◽

◽

Shugen Ma ◽

Yoshinori Honda ◽

Kousuke Inoue ◽

...

Keyword(s):

Stability Margin ◽

Static Stability ◽

Quadruped Robot ◽

Body Posture ◽

Gait Transition ◽

Minimum Number ◽

Motion Speed ◽

Arbitrary Body ◽

Time Required ◽

Foot Position

We propose successive gait transition with arbitrary body posture to enable a quadruped robot to walk statically and omnidirectionally on a slope. Body posture is determined by rotation around 3 axes, roll, pitch, and yaw. Successive gait transition with a minimum number of steps on a slope is realizable using common foot position before and after gait transition. The time required to transit between gaits is reduced by carefully designing foot position in crawling and rotating while limiting foot reachable region on a slope. The robot thus walks into any direction with arbitrary body postures. In this study, we also verify a tradeoff relation between motion speed and body posture. Computer simulation and experiments verified the feasibility of our proposed method and the stability of gait transition based on static stability margin.

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Night-to-Night Variability of Sleep in Children With ADHD and Typically Developing Controls

Journal of Attention Disorders ◽

10.1177/1087054715575065 ◽

2015 ◽

Vol 22 (10) ◽

pp. 942-946 ◽

Cited By ~ 3

Author(s):

Abbey Poirier ◽

Penny Corkum

Keyword(s):

Mental Health ◽

Sleep Duration ◽

Sleep Problems ◽

Mental Health Disorders ◽

Typically Developing ◽

Children With Adhd ◽

Sleep Parameters ◽

Health Disorders ◽

Objective Research ◽

Age And Sex

Objective: Research results on the nature of sleep problems in children with ADHD are highly inconsistent. It is frequently reported that children with ADHD show more night-to-night variability in sleep than their typically developing (TD) peers, but this finding is also inconsistent. Lack of methodological control may account for these inconsistent findings. The current study examined the night-to-night variability of sleep between TD children and children with ADHD who were rigorously diagnosed, medication naïve, and free from comorbid mental health disorders. Method: Sleep parameters were analyzed for night-to-night variability across 4 weekday nights using actigraphy in 50 children with ADHD and 50 age- and sex-matched TD children. Results: There was a significant night-to-night variability for only sleep duration, but this was similar in both groups. Conclusion: These findings suggest that sleep problems in children with ADHD are not due to greater variability in sleep parameters relative to their TD peers.

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Self-reported sleep problems are related to cortical thinning in aging but not memory decline and amyloid-β accumulation – results from the Lifebrain consortium

10.1101/2020.04.28.065474 ◽

2020 ◽

Author(s):

Anders M. Fjell ◽

Øystein Sørensen ◽

Inge K. Amlien ◽

David Bartrés-Faz ◽

Andreas M. Brandmaier ◽

...

Keyword(s):

Episodic Memory ◽

Sleep Quality ◽

Pyramidal Neurons ◽

Sleep Problems ◽

High Expression ◽

Brain Atlas ◽

Memory Decline ◽

Cortical Thinning ◽

Expression Of Genes ◽

Sleep Parameters

AbstractBackgroundOlder persons with poor sleep are more likely to develop neurodegenerative disease, but the causality underlying this association is unclear. To move towards explanation, we examine whether sleep quality and quantity are similarly associated with brain changes across the adult lifespan.MethodsAssociations between self-reported sleep parameters (Pittsburgh Sleep Quality Index;PSQI) and longitudinal cortical change were tested using five samples from the Lifebrain consortium (n=2205, 4363 MRIs, 18-92 years). Analyses were augmented by considering episodic memory change, gene expression from the Allen Human Brain Atlas, and amyloid-beta (Aβ) accumulation (n=1980).ResultsPSQI components sleep problems and low sleep quality were related to thinning of the right lateral temporal cortex. The association with sleep problems emerged after 60 years, especially in regions with high expression of genes related to oligodendrocytes and S1 pyramidal neurons. BMI and symptoms of depression had negligible effects. Sleep problems were neither related to longitudinal change in episodic memory function nor to Aβ accumulation, suggesting that sleep-related cortical changes were independent of AD neuropathology and cognitive decline.ConclusionWorse self-reported sleep in later adulthood was associated with more cortical thinning in regions of high expression of genes related to oligodendrocytes and S1 pyramidal neurons, but not to Aβ accumulation or memory decline. The relationship to cortical brain change suggests that self-reported sleep parameters are relevant in lifespan studies, but small effect sizes, except for a few restricted regions, indicate that self-reported sleep is not a good biomarker of general cortical degeneration in healthy older adults.

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Sleep Pattern and Problems in Young Children Visiting Outpatient Department of a Tertiary Level Hospital in Kathmandu, Nepal

Sleep Disorders ◽

10.1155/2020/8846288 ◽

2020 ◽

Vol 2020 ◽

pp. 1-5

Author(s):

Shrijana Pandey ◽

Shristi Bhattarai ◽

Anwesh Bhatta

Keyword(s):

Young Children ◽

Sleep Problems ◽

College Teaching ◽

Cross Sectional Study ◽

Outpatient Department ◽

Night Time ◽

Cross Sectional ◽

Medical College ◽

Sleep Parameters ◽

Waking Up

Background. Sleep is an important parameter of a child’s growth and development. The pattern and duration of sleep varies with age. Sleep problems are a common occurrence during childhood days, and these problems that establish in childhood are presumed to continue later in life. Many times, parental concerns regarding their child’s sleep problems like difficulty in putting to sleep, frequent night time awakening, and waking up early are overlooked during their visits to the hospital. Objective. The aim of this study was to find out the sleep patterns and problems of children aged six to thirty-six months. Methodology. A cross-sectional study was conducted at the pediatric outpatient department of Kathmandu Medical College Teaching Hospital from October, 2019 till March, 2020. Two hundred and forty-nine respondents were chosen purposively and were given questionnaires to be filled out. Research instrument was a standard, Nepali version of a structured questionnaire called Brief Infant Sleep Questionnaire (BISQ) which contained questions related to sleep parameters and sleep problems existing among young children of 6-36 months. Mean, standard deviation, frequencies, and Kruskal Wallis test were used for statistical analysis. Results. The mean duration of total sleep was 12.12 ± 2.00 hours, while that of night sleep was 9.22 ± 1.19 hours and mean daytime nap was 2.90 ± 1.66 hours. Most of the children (96%) coslept with their parents, and 55% of the children had feeding as a bedtime ritual. Overall, 19.6% of the children had sleep problems as identified by BISQ although only 5.6% of the parents perceived that their children had it. Conclusions. Sleep problems were present among young Nepalese children included in our study, and sleep assessment should be a part of every health checkup for children.

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Impact of Digital Monitoring, Assessment and Cognitive Behavioral Therapy on Subjective Sleep Quality, Workplace Productivity and Health Related Quality of Life: Observational Study (Preprint)

10.2196/preprints.13181 ◽

2018 ◽

Author(s):

Yuval Altman ◽

Shuli Eyal ◽

Anda Baharav ◽

Kyle Niejadlik

Keyword(s):

Sleep Problems ◽

Behavioral Therapy ◽

Sleep Onset ◽

Work Productivity ◽

Average Amount ◽

Subjective Sleep ◽

Sleep Parameters ◽

Smart Mobile

BACKGROUND Sleep difficulties negatively impact health, performance and quality of life, as about a third of the general population suffers from at least one insomnia symptom. Recent studies link insomnia with reduced work productivity, resulting in extensive losses for employees, employers and insurers. Cognitive behavioral therapy for insomnia (CBTi) is recommended as first-line treatment for insomnia and the ubiquity of smart mobile devices allows for promising approaches to overcome some of the limitations surrounding it. OBJECTIVE Our aim was to propose a comprehensive sleep solution for smart mobile devices, and to characterize the effects of this solution, while using adequate sample sizes. METHODS Employees of a Fortune-50 company were randomly selected, all with a Pittsburgh Sleep Quality Index (PSQI) larger than 8. Subjects were randomly assigned to either an intervention group (IG, n=247) or a control group (CG, n=249), and were asked to fill several questionnaires, in addition to the PSQI. Questionnaires were completed pre-treatment, post-treatment at six weeks and a follow-up after two months. People in the IG were provided with a sleep assessment and therapy service via a mobile app (SleepRate). De-identified objective and subjective sleep data were acquired on a nightly basis, along with a digital sleep diary. Sleep parameters included sleep onset (SO), wake after sleep onset (WASO), sleep efficiency (SE) and sleep satisfaction (SS). Sleep problems, such as symptoms of insomnia, were detected based on the sleep data and several questionnaires. Subjects in the IG were then offered treatment to address the detected sleep problems. For subjects with symptoms of insomnia, average sleep parameters during the assessment week (AW) were compared to those during the last week in treatment (LW). RESULTS Post-treatment average PSQI was lower for the IG (8.5), compared to that of the CG (10.9, p=.005), as were absenteeism (IG: 0.39%, CG: 1.0%, p=.06) and presenteeism (IG: 15.6%, CG: 21.4%, p=.02). The average amount of healthy days was significantly higher for the IG (22.5 days) compared to that of the CG (18.6 days, p=.005). At follow-up, average PSQI of the IG was significantly lower (7.1) than that of the CG (10.4, p=.005), as well as absenteeism (IG: 0.15%, CG: 0.84%, p=.03) and presenteeism (IG: 11.9%, CG: 23.5%, p=.005), while the average amount of healthy days was significantly higher (IG: 23.8, CG: 19.0, p=.005). For subjects in the IG, subjective SE was significantly higher at LW (89.1±12.3%, mean±SD) compared to that at the AW (87.5±9.8%, p=.025), WASO significantly shortened (AW: 25.7±27minutes, LW: 19.8±18.4minutes, p=.011), as SS increased significantly (AW: 49.2±11.5, LW: 53±15.4, p=.003). CONCLUSIONS The use of a mobile sleep solution improved the subjective sleep perception in the IG and facilitated a substantial increase in work productivity.

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