Recreational screen time behaviour among ambulatory children and adolescents diagnosed with cerebral palsy: A cross-sectional analysis.

AIM: To describe the recreational screen time behaviour of 8-16-year-olds diagnosed with cerebral palsy (CP) and explore associations between health-related quality of life, sleep duration and physical activity behaviour versus screen time. METHODS: This cross-sectional study used proxy-reported questionnaire data of 381 ambulatory (with or without assistance) 8-16-year-olds diagnosed with CP corresponding to Gross Motor Function Classification System (GMFCS) levels I-III. Descriptive statistics were used to report age, sex and the GMFCS level. The potential associations of health-related quality of life, physical activity behaviour and sleep duration (dependent variables) versus screen time (independent variable) were determined using multiple linear regression. Health-related quality of life was evaluated using the Pediatric Quality of Life Inventory, including seven dimensions: Daily Activities; School Activities; Movement and Balance; Pain and Hurt; Fatigue; Eating Activities; and Speech and Communication. RESULTS: The participants spent a median screen time of 3.9 h daily. The boys spent a longer screen time during weekends than the girls (p = 0.003). Boys spent more time on games (p < 0.001), whereas girls spent more time on social media and video calls (p < 0.001). Increasing age (p < 0.001) was associated with increased screen time but did not differ between the GMFCS levels. Sleep duration, perceived fatigue and perceived movement and balance correlated negatively with screen time. CONCLUSION: This study sheds light on the recreational screen time habits of ambulatory children and adolescents diagnosed with CP. Further investigation into the observed associations is warranted to investigate potential causation and relationships between sleep behaviour, quality of life and screen time behaviour.

Tackling physical inactivity in Scandinavia: a narrative review of reviews supplemented by expert interviews.

Aims: This study aims to identify physical inactivity-related challenges and motives, based on reviews and supplemented by expert interviews with Danish national experts on physical inactivity, providing a general discussion of the subject ultimately generating knowledge useable in a Scandinavian context. Methods: This study is framed as a narrative review of scientific review literature on physical inactivity, limited to the general population. The review is supplemented by expert interviews with Danish national experts on physical inactivity. We used thematic coding of the included reviews, while using hermeneutic interpretation analysis for the expert interviews. Results: Based on 11 included reviews, we highlighted four themes based on our analysis of reviews: (a) socioeconomic determinants of physical activity; (b) life-course perspective; (c) physical inactivity and older adults aged 60+ years; and (d) intervention recommendations. The supplementary expert interviews revealed three additional themes: (a) the individual history with physical activity; (b) sporting organisation importance; and (c) society responsibility for physical inactivity. Conclusions: Collectively this study concludes, based on review and expert interviews, that a number of determinants and correlations for physical inactivity affect the individual from various socioecological levels. Based on this review, we suggest moving beyond the 'upstream' public health approach of randomised controlled trials and consider complex interventions targeting physical inactivity from several levels. Physical inactivity should be acknowledged as a 'wicked problem' that requires a systems-based approach instead of a single quick fix. Future work with physical inactivity would profit from focus on the life-course perspective, sporting clubs' responsiveness and physical literacy.

Predictors of Physical Activity Levels in Ambulant/Semiambulant Children and Adolescents With Cerebral Palsy: A Clinical Cohort Study.

Children and adolescents with cerebral palsy (CP) show a reduced physical activity (PA) level compared with their typically developed peers. This study aimed to identify potential predictors of objectively evaluated habitual PA using data from a national clinical registry-the Cerebral Palsy Follow-Up Program (CPFP)-and proxy-reported questionnaires. Data from the CPFP database showed that female sex was associated with a lower PA level. Additional questionnaire data revealed age, popliteal angle limitation, Pediatric Outcomes Data Collection Instrument-Sports and Physical Functioning Scale score, screen time, Functional Mobility Scale score at 50 m, and fatigue as predictors. The proposed models can be used for the prediction and early detection of the PA level and consequently for the potential improvement among ambulant/semiambulant individuals with CP. Further research should investigate the predictive impact of personal, social, and environmental factors on the PA level and the gap in PA levels between girls and boys.

Exceeding 2-h sedentary time per day is not associated with moderate to severe spinal pain in 11- to 13-year-olds: a cross-sectional analysis.

Neck, mid-back and low back pain, collectively known as spinal pain, become more common with increasing age across childhood and adolescence. A common belief among the general community is that sedentary time, including screen time, in adolescents is associated with spinal pain. We aimed to investigate whether exceeding 2-h of sedentary time per day is associated with moderate to severe spinal pain in a sample of Danish adolescents aged 11-13 years. We performed a cross-sectional analysis of the SPACE study baseline data (2010). Adolescents self-reported their spinal pain (outcome) via the Young Spine Questionnaire and duration of engagement in sedentary behaviours (exposure). We provide estimates of associations as odds ratios with 95% confidence intervals, stratified by age and sex. The sample comprised 1,303 adolescents (48.7% female, mean age 12.5 years, range 10.9-14.3 years). Approximately 9 out of 10 adolescents exceeded 2-h sedentary time on weekdays outside of school (88.9%) and weekend days (89.9%). Close to one-quarter, 23.3% (95%CI: 21.0-25.6), of participants experienced moderate to severe spinal pain. We found no association between exceeding 2-h sedentary time per day and experiencing moderate to severe spinal pain; odds ratios ranged from 0.34 (95%CI: 0.04-3.20) to 4.65 (95%CI: 0.26-82.44).Conclusion: We found no association between exceeding 2- or 5-h of sedentary time per day and moderate to severe spinal pain in this sample of 11-13-year-old Danish adolescents. Our cross-sectional analysis does not consider the longitudinal or complex sequences of events necessary to address predictive or causal questions. What is Known: • Up to a third of adolescents experience moderate to severe spinal pain, predisposing them to chronic spinal pain in adulthood. • Frequent and excessive sedentary time is associated with poor overall health in adolescents; there is conflicting evidence to suggest whether it is also related to spinal pain. What is New: • We found no association between sedentary time and moderate to severe spinal pain in 11- to 13-year-old Danes.

Exploring implementation of a nationwide requirement to increase physical activity in the curriculum in Danish public schools: a mixed methods study.

BACKGROUND: In 2014, the Danish Government introduced a wide-ranging school reform that applied to all public schools in Denmark. A distinctive feature of the reform was that it became mandatory to implement an average of 45 min of daily physical activity within the curriculum. Using the RE-AIM framework as an evaluation tool, the objective of the current study was to evaluate the reach, effectiveness, adoption, implementation, and maintenance of mandatory physical activity within the curriculum at ten Danish schools. METHODS: A complementary mixed-methods approach using accelerometers, questionnaires, and semi-structured interviews was conducted. A total of 10 schools were invited to participate, including 846 students, 76 teachers, and 10 school managers on various levels. Students were invited to wear an accelerometer for seven consecutive days. Teachers were invited to participate in a questionnaire, and school managers were encouraged to take part in a semi-structured interview. RESULTS: Results showed that, on average, 45.2% of the students were active at least 45 min daily within the curriculum. Teacher and school management interest in physical activity, competencies development, and shared decision-making were identified as central factors for adoption of the requirement. Scheduling physical activity within scheduels and collaborations with external parties were found to influence implementation. Finally, internal coordination, motivated school staff, and school management priority were identified as central factors for maintenance. CONCLUSIONS: This study provides an evaluation on a nationwide physical activity requirement in Danish public schools. When introducing a wide-ranging nation-wide requirement on physical activity within the curriculum, school managers need to prioritize and support the implementation process. Teachers need to be involved in the decision processes in order to ensure motivation and local ownership. The study also highlights the benefits of an internal coordinator as well as development of a shared strategy among schools, municipalities, and other stakeholders in order to succeed with the implementation.

Associations of built environment and proximity of food outlets with weight status: Analysis from 14 cities in 10 countries.

The study aimed to examine associations of neighborhood built environments and proximity of food outlets (BE measures) with body weight status using pooled data from an international study (IPEN Adult). Objective BE measures were calculated using geographic information systems for 10,008 participants (4463 male, 45%) aged 16-66 years in 14 cities. Participants self-reported proximity to three types of food outlets. Outcomes were body mass index (BMI) and overweight/obesity status. Male and female weight status associations with BE measures were estimated by generalized additive mixed models. Proportion (95% CI) of overweight (BMI 25 to <30) ranged from 16.6% (13.1, 19.8) to 41.1% (37.3, 44.7), and obesity (BMI ≥ 30) from 2.9% (1.3, 4.4) to 31.3% (27.7, 34.7), with Hong Kong being the lowest and Cuernavaca, Mexico highest for both proportions. Results differed by sex. Greater street intersection density, public transport density and perceived proximity to restaurants (males) were associated with lower odds of overweight/obesity (BMI ≥ 25). Proximity to public transport stops (females) was associated with higher odds of overweight/obesity. Composite BE measures were more strongly related to BMI and overweight/obesity status than single variables among men but not women. One standard deviation improvement in the composite measures of BE was associated with small reductions of 0.1-0.5% in BMI but meaningful reductions of 2.5-5.3% in the odds of overweight/obesity. Effects were linear and generalizable across cities. Neighborhoods designed to support public transport, with food outlets within walking distance, may contribute to global obesity control.

Copenhagen Consensus statement 2019: physical activity and ageing.

From 19th to 22nd November 2018, 26 researchers representing nine countries and a variety of academic disciplines met in Snekkersten, Denmark, to reach evidence-based consensus about physical activity and older adults. It was recognised that the term 'older adults' represents a highly heterogeneous population. It encompasses those that remain highly active and healthy throughout the life-course with a high intrinsic capacity to the very old and frail with low intrinsic capacity. The consensus is drawn from a wide range of research methodologies within epidemiology, medicine, physiology, neuroscience, psychology and sociology, recognising the strength and limitations of each of the methods. Much of the evidence presented in the statements is based on longitudinal associations from observational and randomised controlled intervention studies, as well as quantitative and qualitative social studies in relatively healthy community-dwelling older adults. Nevertheless, we also considered research with frail older adults and those with age-associated neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, and in a few cases molecular and cellular outcome measures from animal studies. The consensus statements distinguish between physical activity and exercise. Physical activity is used as an umbrella term that includes both structured and unstructured forms of leisure, transport, domestic and work-related activities. Physical activity entails body movement that increases energy expenditure relative to rest, and is often characterised in terms of intensity from light, to moderate to vigorous. Exercise is defined as a subset of structured physical activities that are more specifically designed to improve cardiorespiratory fitness, cognitive function, flexibility balance, strength and/or power. This statement presents the consensus on the effects of physical activity on older adults' fitness, health, cognitive functioning, functional capacity, engagement, motivation, psychological well-being and social inclusion. It also covers the consensus on physical activity implementation strategies. While it is recognised that adverse events can occur during exercise, the risk can be minimised by carefully choosing the type of activity undertaken and by consultation with the individual's physician when warranted, for example, when the individual is frail, has a number of co-morbidities, or has exercise-related symptoms, such as chest pain, heart arrhythmia or dizziness. The consensus was obtained through an iterative process that began with the presentation of the state-of-the-science in each domain, followed by group and plenary discussions. Ultimately, the participants reached agreement on the 30-item consensus statements.

Associations of neighborhood environmental attributes with adults' objectively-assessed sedentary time: IPEN adult multi-country study.

Neighborhood environmental attributes have been found to be associated with residents' time spent walking and in physical activity, in studies from single countries and in multiple-country investigations. There are, however, mixed findings on such environmental relationships with sedentary (sitting) time, which primarily have used evidence derived from single-country investigations with self-reported behavioral outcome measures. We examined potential relationships of neighborhood environmental attributes with objectively-assessed sedentary time using data from 5712 adults recruited from higher and lower socio-economic status neighborhoods in 12 sites in 10 countries, between 2002 and 2011. Ten perceived neighborhood attributes, derived from an internationally-validated scale, were assessed by questionnaire. Sedentary time was derived from hip-worn accelerometer data. Associations of individual environmental attributes and a composite environmental index with sedentary time were estimated using generalized additive mixed models. In fully adjusted models, higher street connectivity was significantly related to lower sedentary time. Residential density, pedestrian infrastructure and safety, and lack of barriers to walking were related to higher sedentary time. Aesthetics and safety from crime were related to less sedentary time in women only. The predicted difference in sedentary time between those with the minimum versus maximum composite environmental index values was 71 min/day. Overall, certain built environment attributes, including street connectivity, land use mix and aesthetics were found to be related to sedentary behavior in both expected and unexpected directions. Further research using context-specific measures of sedentary time is required to improve understanding of the potential role of built environment characteristics as influences on adults' sedentary behavior.

Protocol for evaluating the impact of a national school policy on physical activity levels in Danish children and adolescents: the PHASAR study - a natural experiment.

BACKGROUND: In 2014 the Danish Government introduced a wide-ranging school reform that applies to all public schools in Denmark. The reform involves changes in several aspects of the school structure and content. In a physical activity promotion perspective, a distinctive feature of the school reform is that it has become mandatory to integrate an average of 45 min of daily physical activity in the regular school day. The overarching objective of the PHASAR study is to evaluate the implementation and effect of this ambitious policy-driven physical activity promotion initiative on physical activity and overweight. This paper describes in detail the study protocol. METHODS: The evaluation is divided into a quantitative effect evaluation and a combined quantitative and qualitative process evaluation. A total of 31 schools are enrolled in the PHASAR study including more than 2,000 school-aged children. Objectively measured physical activity data are obtained in the PHASAR study in 2017/18 and compared to repeated cross sectional data collected in four historical school-based studies from 1998 to 2012. Body mass index data from 2012 to 2018 will be collected from The Child Database, which includes repeated cross-sectional assessments on approximately 100,000 children annually. In the absence of a control group, interrupted time-series analysis will be used to evaluate pre- and post-reform physical activity and body mass index levels and trends. A characterization of the school environment for physical activity promotion on a political, environmental, organizational and individual level and school implementation processes will be conducted to evaluate the implementation process. Data will be collected using interviews, surveys, document analyses and observations. DISCUSSION: The PHASAR study is a rare opportunity to evaluate the effectiveness of a nation-wide policy-driven school-based physical activity promotion initiative. The use of objectively measured pre- and post-reform physical activity and body mass index data combined with a characterization of the school implementation processes for physical activity promotion will provide a comprehensive source to evaluate the school reform. The study findings have the potential to influence national and international policy makers, health professionals and school staff.

Physical activity in relation to urban environments in 14 cities worldwide: a cross-sectional study.

BACKGROUND: Physical inactivity is a global pandemic responsible for over 5 million deaths annually through its effects on multiple non-communicable diseases. We aimed to document how objectively measured attributes of the urban environment are related to objectively measured physical activity, in an international sample of adults. METHODS: We based our analyses on the International Physical activity and Environment Network (IPEN) adult study, which was a coordinated, international, cross-sectional study. Participants were sampled from neighbourhoods with varied levels of walkability and socioeconomic status. The present analyses of data from the IPEN adult study included 6822 adults aged 18-66 years from 14 cities in ten countries on five continents. Indicators of walkability, public transport access, and park access were assessed in 1·0 km and 0·5 km street network buffers around each participant's residential address with geographic information systems. Mean daily minutes of moderate-to-vigorous-intensity physical activity were measured with 4-7 days of accelerometer monitoring. Associations between environmental attributes and physical activity were estimated using generalised additive mixed models with gamma variance and logarithmic link functions. RESULTS: Four of six environmental attributes were significantly, positively, and linearly related to physical activity in the single variable models: net residential density (exp[b] 1·006 [95% CI 1·003-1·009]; p=0·001), intersection density (1·069 [1·011-1·130]; p=0·019), public transport density (1·037 [1·018-1·056]; p=0·0007), and number of parks (1·146 [1·033-1·272]; p=0·010). Mixed land use and distance to nearest public transport point were not related to physical activity. The difference in physical activity between participants living in the most and least activity-friendly neighbourhoods ranged from 68 min/week to 89 min/week, which represents 45-59% of the 150 min/week recommended by guidelines. INTERPRETATION: Design of urban environments has the potential to contribute substantially to physical activity. Similarity of findings across cities suggests the promise of engaging urban planning, transportation, and parks sectors in efforts to reduce the health burden of the global physical inactivity pandemic. FUNDING: Funding for coordination of the IPEN adult study, including the present analysis, was provided by the National Cancer Institute of National Institutes of Health (CA127296) with studies in each country funded by different sources.

Move the Neighbourhood: Study design of a community-based participatory public open space intervention in a Danish deprived neighbourhood to promote active living.

BACKGROUND: A limited amount of research has examined the effect of changing public open spaces on active living. This paper will present the study protocol of a community-based intervention study co-designed in an interdisciplinary collaboration with community members to develop urban installations highly tailored to promote active living among children (10-13-years-old) and seniors (>60-years-old) in a deprived neighbourhood in Copenhagen. METHODS: The study builds on a quasi-experimental study design with two sub-studies: 1) a children study and 2) a senior study. The interventions will be developed, designed and implemented in collaboration with local children and seniors, respectively, using different co-design tools and methods. We will evaluate the effect of the interventions on children's and senior's use of the new-built urban installations using accelerometers in combination with GPS as well as systematic observation using the System for Observing Play and Recreation in Communities (SOPARC). A process evaluation with focus groups consisting of the various stakeholders in the two sub-studies will be used to gain knowledge of the intervention processes. DISCUSSION: The paper presents new approaches in the field of public open space interventions through interdisciplinary collaboration, participatory co-design approach and combination of measurements. Using both effect and process evaluations the study will provide unique insights in the role and importance of the interdisciplinary collaboration, participatory processes, and tailoring changes in public open space to local needs and wishes. These results can be used to guide urban renewal projects in deprived neighbourhoods in the future. TRIAL REGISTRATION: Retrospectively registered with study ID ISRCTN50036837 . Date of registration: 16 December 2016.

Schoolyard upgrade in a randomized controlled study design-how are school interventions associated with adolescents' perception of opportunities and recess physical activity.

School recess physical activity is important for adolescent s health and development, and several studies have established evidence based on cross-sectional studies that it is influenced by the environment in the schoolyard. The aim of this study was to investigate the effect and variation across schools of a school-based intervention on students perceived opportunities for physical activity in the schoolyard, and to evaluate if an improved collective perception of opportunities was followed by an increase in PA during recess for the 13-15 year-old students. The intervention components included schoolyard renovation; mandatory outdoor recess; and increased adult supervision and support. Students collective perceptions were evaluated by a newly developed Schoolyard index (SYi) with seven items, and physical activity was objectively measured with accelerometer. We found variations in the change of student perceptions across the intervention schools, and that a one unit increase in the Schoolyard index (SYi) led to a 12% increase in recess PA. This study shows that adolescent PA during recess can be increased through a multicomponent intervention. The prospect for making an impact is low and according to the process analysis dependent on direct involvement; active and supportive adults; and varied, connected and well located facilities.

Space, body, time and relationship experiences of recess physical activity: a qualitative case study among the least physical active schoolchildren.

BACKGROUND: Increasing recess physical activity has been the aim of several interventions, as this setting can provide numerous physical activity opportunities. However, it is unclear if these interventions are equally effective for all children, or if they only appeal to children who are already physically active. This study was conducted to explore the least physically active children's "lived experiences" within four existential lifeworlds linked to physical activity during recess: space, body, time, and relations. METHODS: The study builds on ethnographic fieldwork in a public school in Denmark using a combination of participatory photo interviews and participant observation. Thirty-seven grade five children (11-12 years old) were grouped in quartiles based on their objectively measured daily physical activity levels. Eight children in the lowest activity quartile (six girls) were selected to participate in the study. To avoid stigmatising and to make generalisations more reliable we further recruited eight children from the two highest activity quartiles (four girls) to participate. RESULTS: An analysis of the least physically active children's "lived experiences" of space, body, time and relations revealed several key factors influencing their recess physical activity: perceived classroom safety, indoor cosiness, lack of attractive outdoor facilities, bodily dissatisfaction, bodily complaints, tiredness, feeling bored, and peer influence. CONCLUSION: We found that the four existential lifeworlds provided an in-depth understanding of the least physically active children's "lived experiences" of recess physical activity. Our findings imply that specific intervention strategies might be needed to increase the least physically active children's physical activity level. For example, rethinking the classroom as a space for physical activity, designing schoolyards with smaller secluded spaces and varied facilities, improving children's self-esteem and body image, e.g., during physical education, and creating teacher organised play activities during recess.

Activating schoolyards: study design of a quasi-experimental schoolyard intervention study.

BACKGROUND: The aim of the Activating Schoolyards Study is to develop, implement, document and assess a comprehensive schoolyard intervention to promote physical activity (PA) during school recess for primary school children (grade 4-8). The intervention is designed to implement organizational and structural changes in the physical environment. METHOD: The study builds on a quasi-experimental study design using a mixed method approach including: 1) an exploratory study aimed at providing input for the developing process; 2) an evaluation of the effect of the interventions using a combination of accelerometer, GPS and GIS; 3) a process evaluation facilitating the intervention development process and identifying barriers and facilitators in the implementation process; 4) a post-intervention end-user evaluation aimed at exploring who uses the schoolyards and how the schoolyards are used. The seven project schools (cases) were selected by means of an open competition and the interventions were developed using a participatory bottom-up approach. DISCUSSION: The participatory approach and case selection strategy make the study design novel. The use of a mixed methods design including qualitative as well as quantitative methods can be seen as a strength, as the different types of data complement each other and results of one part of the study informed the following parts. A unique aspect of our study is the use of accelerometers in combination with GPS and GIS in the effect evaluation to objectively determine where and how active the students are in the schoolyard, before and after the intervention. This provides a type of data that, to our knowledge, has not been used before in schoolyard interventions. Exploring the change in behavior in relation to specific intervention elements in the schoolyard will lead to recommendations for schools undergoing schoolyard renovations at some point in the future.

Using accelerometers and global positioning system devices to assess gender and age differences in children's school, transport, leisure and home based physical activity.

BACKGROUND: Knowledge on domain-specific physical activity (PA) has the potential to advance public health interventions and inform new policies promoting children's PA. The purpose of this study is to identify and assess domains (leisure, school, transport, home) and subdomains (e.g., recess, playgrounds, and urban green space) for week day moderate to vigorous PA (MVPA) using objective measures and investigate gender and age differences. METHODS: Participants included 367 Danish children and adolescents (11-16 years, 52% girls) with combined accelerometer and Global Positioning System (GPS) data (mean 2.5 days, 12.7 hrs/day). The Personal Activity and Location Measurement System and a purpose-built database assessed data in 15-second epochs to determine PA and assign epochs to 4 domains and 11 subdomains. Frequencies and proportions of time spent in MVPA were determined and differences assessed using multi-level modeling. RESULTS: More than 90% of MVPA was objectively assigned to domains/subdomains. Boys accumulated more MVPA overall, in leisure, school and transport (all p < 0.05). Children compared with adolescents accumulated more MVPA, primarily through more school MVPA (p < 0.05). Boys spent a large proportion of time accumulating MVPA in playgrounds, active transport, Physical Education, sports facilities, urban green space and school grounds. Girls spent a significant proportion of time accumulating MVPA in active transport and playgrounds. No gender or age differences were found in the home domain. CONCLUSIONS: Large variations were found in PA frequency and intensity across domains/subdomains. Significant gender differences were found, with girls being less active in almost all domains and subdomains. Objectively measured patterns of PA across domains/subdomains can be used to better tailor PA interventions and inform future policies for promoting child PA.

Barriers for recess physical activity: a gender specific qualitative focus group exploration.

BACKGROUND: Many children, in particular girls, do not reach the recommended amount of daily physical activity. School recess provides an opportunity for both boys and girls to be physically active, but barriers to recess physical activity are not well understood. This study explores gender differences in children's perceptions of barriers to recess physical activity. Based on the socio-ecological model four types of environmental barriers were distinguished: natural, social, physical and organizational environment. METHODS: Data were collected through 17 focus groups (at 17 different schools) with in total 111 children (53 boys) from fourth grade, with a mean age of 10.4 years. The focus groups included an open group discussion, go-along group interviews, and a gender segregated post-it note activity. A content analysis of the post-it notes was used to rank the children's perceived barriers. This was verified by a thematic analysis of transcripts from the open discussions and go-along interviews. RESULTS: The most frequently identified barriers for both boys and girls were weather, conflicts, lack of space, lack of play facilities and a newly-found barrier, use of electronic devices. While boys and girls identified the same barriers, there were both inter- and intra-gender differences in the perception of these barriers. Weather was a barrier for all children, apart from the most active boys. Conflicts were perceived as a barrier particularly by those boys who played ballgames. Girls said they would like to have more secluded areas added to the school playground, even in large schoolyards where lack of space was not a barrier. This aligned with girls' requests for more "hanging-out" facilities, whereas boys primarily wanted activity promoting facilities. CONCLUSION: Based on the results from this study, we recommend promoting recess physical activity through a combination of actions, addressing barriers within the natural, social, physical and organizational environment.

Limited associations between passive range of motion and gross motor function in ambulant/semi-ambulant children and adolescents with cerebral palsy: A cross-sectional study.

BACKGROUND AND AIM: Cerebral palsy (CP) is the most common childhood motor disability, and the Cerebral Palsy Follow-Up Program (CPUP) in Nordic countries uses a traffic light system for passive range of motion (ROM) assessment to aid interpretation and guide decisions regarding interventions. However, the arbitrary chosen ROM threshold values and their potential clinical impact are uncertain. We investigated whether lower extremity ROM values were positively associated with gross motor function and whether gross motor function scores differ between the CPUP ROM thresholds. METHODS: This was a cross-sectional analysis of CPUP data for 841 ambulatory children and adolescents with CP, at a mean (SD) age of 9 (3). Regression analyses were employed to explore the relationship between gross motor capacity and performance (using the Gross Motor Function Measure (GMFM-66) and the Functional Mobility Scale (FMS) 5/50/500 m, respectively) and lower extremity ROM, measured with a goniometer. ROM was assessed both as continuous and categorical variables. RESULTS: We found that two out of ten continuous ROM measures were positively associated with gross motor function. Limited differences in gross motor function between the ROM thresholds were seen for seven out of ten ROM measures. The CPUP traffic light thresholds primarily differentiated gross motor function between the red and green categories, predominantly for the subgroup of participants with bilateral spastic CP. CONCLUSION: Limited associations between passive ROM and gross motor function in children and adolescents with CP were observed, indicating that there is more to consider than ROM when identifying whether interventions are needed.

Impact of a nationwide school policy on body mass index in Danish school children: An interrupted time series analysis.

Objectives: A new school policy mandating 45 min physical activity daily during school was introduced in Denmark in 2014. We aimed to evaluate the effect of this policy on BMI in school-aged children. It was hypothesized that the school policy would decrease BMI, especially in the obese fraction of the population (90th percentile BMI). Study design: This register-based study was conducted as a natural experiment. Methods: Analyses were based on data from The National Child Health Register that contains nationwide data on height and weight from mandatory preventive health examinations completed by school nurses or medical doctors during pre-preparatory classes (0th-3rd grade) and lower secondary education (7th-9th grade). A total of 401,517 children were included in the analyses with annual repeated cross-sectional data covering the period from 2012 to 2018. The effect of the school policy was evaluated using an interrupted time series approach comparing pre- and post-policy slopes in BMI, stratified by sex and age-group. Results: In boys, no significant differences were observed in mean BMI slopes from pre-to post-policy in either age-group. In girls, post-policy slopes were significantly higher compared to pre-policy in both age-groups (0th-3rd grade: ß:0·034 kg/m2, 95%-CI: (0·024; 0·043), p-value: <0·001; 7th-9th grade: ß:0·066 kg/m2, 95%-CI: (0·028; 0·103), p-value: 0·001). No significant differences in slopes were observed in BMI at the 90th percentile from pre-to post-policy for both sexes and across both age-groups. Adjustment for leisure-time physical activity as a potential time-varying confounder did not alter the findings. Conclusions: In conclusion, we did not detect a significant decrease in BMI levels among school-aged children following the introduction of a nationwide school policy specifying daily physical activity in school. If anything, a small positive change in BMI was observed in girls. More research is needed to understand whether structural changes similar to this requirement are able to prevent overweight and obesity in children and adolescents.

Accelerometer data reduction in adolescents: effects on sample retention and bias.

BACKGROUND: Accelerometry is increasingly being recognized as an accurate and reliable method to assess free-living physical activity (PA) in children and adolescents. However, accelerometer data reduction criteria remain inconsistent, and the consequences of excluding participants in for example intervention studies are not well described. In this study, we investigated how different data reduction criteria changed the composition of the adolescent population retained in accelerometer data analysis. METHODS: Accelerometer data (Actigraph GT3X), anthropometric measures and survey data were obtained from 1348 adolescents aged 11-14 years enrolled in the Danish SPACE for physical activity study. Accelerometer data were analysed using different settings for each of the three key data reduction criteria: (1) number of valid days; (2) daily wear time; and (3) non-wear time. The effects of the selected setting on sample retention and PA counts were investigated and compared. Ordinal logistic regression and multilevel mixed-effect linear regression models were used to analyse the impact of differing non-wear time definitions in different subgroups defined by body mass index, age, sex, and self-reported PA and sedentary levels. RESULTS: Increasing the minimum requirements for daily wear time and the number of valid days and applying shorter non-wear definitions, resulted in fewer adolescents retained in the dataset. Moreover, the different settings for non-wear time significantly influenced which participants would be retained in the accelerometer data analyses. Adolescents with a higher BMI (OR:0.93, CI:0.87-0.98, p=0.015) and older adolescents (OR:0.68, CI:0.49-0.95, p=0.025) were more likely to be excluded from analysis using 10 minutes of non-wear compared to longer non-wear time periods. Overweight and older adolescents accumulated more daily non-wear time if the non-wear time setting was short, and the relative difference between groups changed depending on the non-wear setting. Overweight and older adolescents did also accumulate more sedentary time, but this was not significant correlated to the non-wear setting used. CONCLUSIONS: Even small differences in accelerometer data reduction criteria can have substantial impact on sample size and PA and sedentary outcomes. This study highlighted the risk of introducing bias with more overweight and older adolescents excluded from the analysis when using short non-wear time definitions.