Calibration and Cross-Validation of the ActiGraph wGT3X+ Accelerometer for the Estimation of Physical Activity Intensity in Children with Intellectual Disabilities

Data Analytics in Physical Activity Studies With Accelerometers: Scoping Review

BACKGROUND

Monitoring free-living physical activity (PA) through wearable devices enables the real-time assessment of activity features associated with health outcomes and provision of treatment recommendations and adjustments. The conclusions of studies on PA and health depend crucially on reliable statistical analyses of digital data. Data analytics, however, are challenging due to the various metrics adopted for measuring PA, different aims of studies, and complex temporal variations within variables. The application, interpretation, and appropriateness of these analytical tools have yet to be summarized.

OBJECTIVE

This research aimed to review studies that used analytical methods for analyzing PA monitored by accelerometers. Specifically, this review addressed three questions: (1) What metrics are used to describe an individual's free-living daily PA? (2) What are the current analytical tools for analyzing PA data, particularly under the aims of classification, association with health outcomes, and prediction of health events? and (3) What challenges exist in the analyses, and what recommendations for future research are suggested regarding the use of statistical methods in various research tasks?

METHODS

This scoping review was conducted following an existing framework to map research studies by exploring the information about PA. Three databases, PubMed, IEEE Xplore, and the ACM Digital Library, were searched in February 2024 to identify related publications. Eligible articles were classification, association, or prediction studies involving human PA monitored through wearable accelerometers.

RESULTS

After screening 1312 articles, 428 (32.62%) eligible studies were identified and categorized into at least 1 of the following 3 thematic categories: classification (75/428, 17.5%), association (342/428, 79.9%), and prediction (32/428, 7.5%). Most articles (414/428, 96.7%) derived PA variables from 3D acceleration, rather than 1D acceleration. All eligible articles (428/428, 100%) considered PA metrics represented in the time domain, while a small fraction (16/428, 3.7%) also considered PA metrics in the frequency domain. The number of studies evaluating the influence of PA on health conditions has increased greatly. Among the studies in our review, regression-type models were the most prevalent (373/428, 87.1%). The machine learning approach for classification research is also gaining popularity (32/75, 43%). In addition to summary statistics of PA, several recent studies used tools to incorporate PA trajectories and account for temporal patterns, including longitudinal data analysis with repeated PA measurements and functional data analysis with PA as a continuum for time-varying association (68/428, 15.9%).

CONCLUSIONS

Summary metrics can quickly provide descriptions of the strength, frequency, and duration of individuals' overall PA. When the distribution and profile of PA need to be evaluated or detected, considering PA metrics as longitudinal or functional data can provide detailed information and improve the understanding of the role PA plays in health. Depending on the research goal, appropriate analytical tools can ensure the reliability of the scientific findings.

Accelerometer techniques for capturing human movement validated against direct observation: a scoping review

Objective.Accelerometers are devices commonly used to measure human physical activity and sedentary time. Accelerometer capabilities and analytical techniques have evolved rapidly, making it difficult for researchers to keep track of advances and best practices for data processing and analysis. The objective of this scoping review is to determine the existing methods for analyzing accelerometer data for capturing human movement which have been validated against the criterion measure of direct observation.Approach.This scoping review searched 14 academic and 5 grey databases. Two independent raters screened by title and abstract, then full text. Data were extracted using Microsoft Excel and checked by an independent reviewer.Mainresults.The search yielded 1039 papers and the final analysis included 115 papers. A total of 71 unique accelerometer models were used across a total of 4217 participants. While all studies underwent validation from direct observation, most direct observation occurred live (55%) or using recordings (42%). Analysis techniques included machine learning (ML) approaches (22%), the use of existing cut-points (18%), receiver operating characteristic curves to determine cut-points (14%), and other strategies including regressions and non-ML algorithms (8%).Significance.ML techniques are becoming more prevalent and are often used for activity identification. Cut-point methods are still frequently used. Activity intensity is the most assessed activity outcome; however, both the analyses and outcomes assessed vary by wear location. This scoping review provides a comprehensive overview of accelerometer analysis and validation techniques using direct observation and is a useful tool for researchers using accelerometers.

Feasibility of a laboratory-based protocol for measuring energy expenditure and accelerometer calibration in adults with intellectual disabilities

Adults with intellectual disabilities experience numerous health inequalities. Targeting unhealthy lifestyle behaviours, such as high levels of sedentary behaviour and overweight/obesity, is a priority area for improving the health and adults with intellectual disabilities and reducing inequalities. Energy expenditure is a fundamental component of numerous health behaviours and an essential component of various free-living behaviour measurements, e.g. accelerometry. However, little is known about energy expenditure in adults with intellectual disabilities and no population-specific accelerometer data interpretation methods have been calibrated. The limited research in this area suggests that adults with intellectual disabilities have a higher energy expenditure, which requires further exploration, and could have significant impacts of device calibration. However, due to the complex methods required for measuring energy expenditure, it is essential to first evaluate feasibility and develop an effective protocol. This study aims to test the feasibility of a laboratory-based protocol to enable the measurement of energy expenditure and accelerometer calibration in adults with intellectual disabilities.We aimed to recruit ten adults (≥ 18 years) with intellectual disabilities. The protocol involved a total of nine sedentary, stationary, and physical activities, e.g. sitting, lying down, standing, and treadmill walking. Each activity was for 5 min, with one 10 min lying down activity to measure resting energy expenditure. Breath by breath respiratory gas exchange and accelerometry (ActiGraph and ActivPAL) were measured during each activity. Feasibility was assessed descriptively using recruitment and outcome measurement completion rates, and participant/stakeholder feedback.Ten adults (N = 7 female) with intellectual disabilities participated in this study. The recruitment rate was 50% and 90% completed the protocol and all outcome measures. Therefore, the recruitment strategy and protocol are feasible.This study addresses a significant gap in our knowledge relating to exercise laboratory-based research for adults with intellectual disabilities The findings from this study provide essential data that can be used to inform the development of future protocols to measure energy expenditure and for accelerometer calibration in adults with intellectual disabilities.

Using functional principal component analysis (FPCA) to quantify sitting patterns derived from wearable sensors

BACKGROUND

Sedentary behavior (SB) is a recognized risk factor for many chronic diseases. ActiGraph and activPAL are two commonly used wearable accelerometers in SB research. The former measures body movement and the latter measures body posture. The goal of the current study is to quantify the pattern and variation of movement (by ActiGraph activity counts) during activPAL-identified sitting events, and examine associations between patterns and health-related outcomes, such as systolic and diastolic blood pressure (SBP and DBP).

METHODS

The current study included 314 overweight postmenopausal women, who were instructed to wear an activPAL (at thigh) and ActiGraph (at waist) simultaneously for 24 hours a day for a week under free-living conditions. ActiGraph and activPAL data were processed to obtain minute-level time-series outputs. Multilevel functional principal component analysis (MFPCA) was applied to minute-level ActiGraph activity counts within activPAL-identified sitting bouts to investigate variation in movement while sitting across subjects and days. The multilevel approach accounted for the nesting of days within subjects.

RESULTS

At least 90% of the overall variation of activity counts was explained by two subject-level principal components (PC) and six day-level PCs, hence dramatically reducing the dimensions from the original minute-level scale. The first subject-level PC captured patterns of fluctuation in movement during sitting, whereas the second subject-level PC delineated variation in movement during different lengths of sitting bouts: shorter (< 30 minutes), medium (30 -39 minutes) or longer (> 39 minute). The first subject-level PC scores showed positive association with DBP (standardized β ^ : 2.041, standard error: 0.607, adjusted p = 0.007), which implied that lower activity counts (during sitting) were associated with higher DBP.

CONCLUSION

In this work we implemented MFPCA to identify variation in movement patterns during sitting bouts, and showed that these patterns were associated with cardiovascular health. Unlike existing methods, MFPCA does not require pre-specified cut-points to define activity intensity, and thus offers a novel powerful statistical tool to elucidate variation in SB patterns and health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03473145; Registered 22 March 2018; https://clinicaltrials.gov/ct2/show/NCT03473145 ; International Registered Report Identifier (IRRID): DERR1-10.2196/28684.

Changes in Physical Activity Associated With a Multicomponent Weight-Loss Randomized Controlled Trial for Youth With Intellectual Disabilities

Youth with intellectual disabilities engage in low levels of physical activity (PA). An aim of this family-based weight-loss behavioral intervention (FBBI) trial was to increase and sustain PA in these youth. Accelerometry data were available from 21 individuals with intellectual disabilities, age 14-22 years. Each completed the 6-month FBBI, after which 10 completed a 6-month maintenance intervention (FBBI-M), and 11 received no further intervention (FBBI-C). Twenty participated in a further 6-month follow-up. Accelerometry data were analyzed using linear mixed models. During FBBI, mean (SE) moderate to vigorous PA increased by 4.1 (2.5) min/day and light PA by 24.2 (13.5) min/day. Mean (SE) difference in moderate to vigorous PA between participants in FBBI-M and FBBI-C at 18 months was 14.0 (5.1) min/day (p = .005); mean (SE) difference in light PA was 47.4 (27.4) min/day (p = .08). Increasing PA through behavioral intervention is possible in youth with intellectual disabilities.

Moderate-to-vigorous intensity physical activity levels of children with intellectual disability during physical education classes

Background

Physical education (PE) class is an excellent way to improve moderate-to-vigorous intensity physical activity (MVPA). Increasing number of research has explored the children's PA based on movement during PE classes, but data for children with intellectual disability (ID) is still lacking.

Purpose

The purpose of this study was to investigate the current status of MVPA levels of children with ID during PE classes in China, as well as differences of MVPA levels according to gender and grade.

Methods

Accelerometers were used to record MVPA levels of fifty-three children with severe ID from 9 to 16 years of age (mean age: 12.60 ± 1.66 years) during standard PE classes.

Results

The mean time spent in MVPA during PE classes was 8.00 ± 2.10 min, meaning only 22.88% of PE class time was spent in MVPA. As grade levels progresses, time spent in MVPA during PE classes tended to decrease; the fourth-grade children tended to spend more time in MVPA during PE classes compared with the fifth-grade and the sixth-grade (9.15 vs. 7.61 vs. 7.25 min, all p < 0.05). Boys spend significantly more time in MVPA during PE classes than girls; both in the entire sample (9.20 vs. 5.70 min) as well as in each grade (9.76 vs. 6.09 min, 9.35 vs. 5.68 min, 8.31 vs. 5.59 min, all p < 0.05).

Conclusion

Findings from this study indicate that the proportion of PE class spent in the MVPA of children with ID was lower than the 50% recommended by the U.S. Department of Health and Human Services (DHHS) and U.K. Association for Physical Education (AfPE). And the amount of MVPA participation varied by the grade and gender as well as by the activity performed. Therefore, in order to help children with ID achieve MVPA goals, educators need to reevaluate the PE curriculum as well as take due consideration of grade and gender when devising new content.

Associations between Fundamental Movement Skills and Moderate-to-Vigorous Intensity Physical Activity among Chinese Children and Adolescents with Intellectual Disability

Higher physical activity (PA) levels will obtain more health-related benefits for children and adolescents with intellectual disabilities (ID). The mastery of fundamental movement skills (FMS) potentially correlates with PA. This study aimed to examine the associations of FMS with moderate-to-vigorous intensity physical activity (MVPA) levels in children and adolescents with moderate to severe ID. Moreover, this research analyzes whether there are gender and age differences in the association between these two variables. A total of 93 children and adolescents with ID, aged 8-17 years (mean age = 13.27; SD = 3.35), were recruited from a special school located in western China. The time spent in MVPA was measured using waist-worn accelerometers. FMS proficiency was assessed using the Test of Gross Motor Development 2 (TGMD-2). Children and adolescents with ID tend to have delayed maturity of FMS patterns (locomotor skills t (92) = -16.91, p < 0.001, d = 2.48; object control skills t (92) = -25.39, p < 0.001, d = 3.72; total FMS t (92) = -21.83, p < 0.001, d = 3.20) and lower proficiency in objective control skills (t (92) = 3.989, p < 0.001, d = 0.29). A significant positive correlation was found between MVPA and FMS, and this association was moderated by gender and age. For boys, object control skills were a significant predictor of MVPA time (B = 0.842, p < 0.01), whereas locomotor skills were a significant predictor of MVPA time (B = 0.472, p < 0.05) for girls. For children with ID, object control skills were a significant predictor of MVPA time (B = 0.736, p < 0.05). Proficiency in FMS has a positive effect on increasing the level of MVPA in children and adolescents with ID. Gender and age factors should be considered when implementing FMS intervention programs.

Changes in physical activity across a 6-month weight loss intervention in adolescents with intellectual and developmental disabilities

BACKGROUND

Adolescents and young adults with intellectual and developmental disabilities (IDD) have high rates of obesity and low levels of physical activity. This analysis examined changes in light, moderate-to-vigorous physical activity (MVPA) and sedentary time, and the association between changes in MVPA and weight loss in adolescents and young adults with IDD and overweight and obesity participating in a 6-month multi-component weight loss intervention.

METHODS

Adolescents and young adults with IDD and overweight or obesity (body mass index ≥ 85 percentile, n = 110, age ~16 years, 52.7% female) and a parent were randomised to one of three intervention groups: face-to-face delivery/conventional reduced energy diet (n = 36), remote delivery (RD)/conventional reduced energy diet (n = 39), or RD/reduced energy enhanced stop light diet (eSLD) (n = 35.) Participants were asked to engage in 60 min/day of MVPA on 5 or more days/wk. Participants and a parent attended twice monthly education/behavioural counselling sessions with a health educator to assist participants in complying with dietary and MVPA recommendations. Education/counselling in the RD arms was delivered remotely using video conferencing, and self-monitoring of MVPA and daily steps was completed using a wireless activity tracker. Education/counselling in the face-to-face arm was delivered during home-visits and self-monitoring of MVPA and daily steps was completed by self-report using paper tracking forms designed for individuals with IDD. MVPA, light activity, and sedentary time were assessed over 7 days at baseline and 6 months using a portable accelerometer (ActiGraph wGT3x-BT).

RESULTS

Mixed modelling analysis completed using participants with valid accelerometer data (i.e. ≥4-10 h days) at baseline (n = 68) and 6 months (n = 30) revealed no significant changes in light, moderate- MVPA, or sedentary time across the 6-month intervention (all P > 0.05). Participants obtained 15.2 ± 21.5 min/day of MVPA at baseline and 19.7 ± 19.7 min/day at 6 months (P = 0.119). Mixed modelling indicated no significant effects of group (P = 0.79), time (P = 0.10), or group-by-time interaction (P = 0.21) on changes in MVPA from baseline to 6 months. Correlational analysis conducted on participants with valid accelerometer data at both baseline and 6 months (n = 24) revealed no significant associations between baseline sedentary time (r = 0.10, P = 0.40) and baseline MVPA (r = -0.22, P = 0.30) and change in MVPA across the 6-month intervention. Additionally, attendance at education/counselling sessions (r = 0.26, P = 0.22) and frequency of self-monitoring of MVPA were not significantly associated with change in MVPA from baseline to 6 months (r = 0.26, P = 0.44). Baseline MVPA (r = 0.02, P = 0.92) and change in MVPA from baseline to 6 months (r = 0.13, P = 0.30) were not associated with changes in body weight across the 6-month intervention.

CONCLUSION

We observed a non-significant increase in MVPA (30%), which was not associated with the magnitude of weight loss in a sample of adolescents and young adults with IDD who participated in a 6-month multi-component weight loss intervention. Additional strategies to increase MVPA in adolescents and young adults with IDD participating in weight loss interventions need to be developed and evaluated.

Intrapersonal, interpersonal and environmental correlates of moderate to vigorous physical activity and sedentary time in adolescents with intellectual and developmental disabilities

BACKGROUND

Although correlates of physical activity (PA) have been extensively examined in both children and adolescents who are typically developing, little is known about correlates of moderate to vigorous physical activity (MVPA) and sedentary time in adolescents with intellectual and developmental disabilities (IDD). Therefore, we examined intrapersonal, interpersonal and environmental factors and their association with device-based MVPA and sedentary time in adolescents with IDD.

METHODS

MVPA and sedentary time was assessed using a hip-worn ActiGraph model wGT3x-BT tri-axial accelerometer across a 7-day period in adolescents with IDD and one of their parents. Pearson and point-biserial correlations were calculated to inspect the associations of PA (MVPA, sedentary time) with intrapersonal factors (demographic characteristic, BMI, waist circumference, motor ability, muscle strength, grip strength, cardiovascular fitness and self-efficacy for PA), interpersonal factors (parent demographics, parent BMI, parent MVPA and sedentary time, family social support for PA, parent barriers and support for PA, parent's beliefs/attitudes towards PA and number of siblings), and environmental factors (meteorologic season and COVID-19). Ordinary least squares regression was used to estimate the unique contributions of key factors to PA after controlling for participants' age, sex, race, waist circumference and total wear time.

RESULTS

Ninety-two adolescents (15.5 ± 3.0 years old, 21.7% non-White, 6.5% Hispanic, 56.5% female) provided valid accelerometer data. Average sedentary time was 494.6 ± 136.4 min/day and average MVPA was 19.8 ± 24.2 min/day. Age (r = 0.27, P = 0.01), diagnosis of congenital heart disease (r = -0.26, P = 0.01) and parent sedentary time (r = 0.30, P = 0.01) were correlated with sedentary time. BMI (r = -0.24, P = 0.03), waist circumference (r = -0.28, P = 0.01), identifying as White (r = -0.23, P = 0.03) and parent MVPA (r = 0.56, P < 0.001) were correlated with MVPA. After adjusting for the adolescent's age, sex, race, waist circumference, and total wear time, the association between parent and adolescent MVPA remained significant (b = 0.55, P < 0.01, partial η2  = 0.11).

CONCLUSION

The results of this study provide evidence that race, waist circumference and parental MVPA may influence the amount of MVPA in adolescents with IDD. The limited available information and the potential health benefits of increased MVPA highlight the need to evaluate the effectiveness of multi-component interventions targeting both intrapersonal and interpersonal levels to promote increased PA in adolescents with IDD.

A comparison of accelerometer cut-points for measuring physical activity and sedentary time in adolescents with Down syndrome

BACKGROUND

No cut-points have been developed for youth with Down syndrome; there is concern that altered gait patterns, decreased energy expenditure and exercise capacity of individuals with Down syndrome may produce inaccurate physical activity data if accelerometer data are analyzed using cut-points from populations with typical development and other IDD diagnoses.

AIM

To compare physical activity and sedentary time across existing accelerometer cut-point methods in adolescents with Down syndrome.

METHODS

In this cross-sectional analysis, participants diagnosed with Down syndrome (n = 37; 15.5 ± 1.9 years; 57 % female) wore an accelerometer on their non-dominant hip for seven-days. Data were analyzed and compared across four physical activity intensity cut-points: Evenson, Freedson 4-MET, McGarty, and Romanizi.

OUTCOMES & RESULTS

Differences in time spent in each intensity across cut-point methods were evident for sedentary (448-615 min/day), light (72-303 min/day) and moderate-to-vigorous (12-77 min/day) activities. Between 0.0-67.6 % of the sample met the physical activity guidelines, depending on the cut-point method selected.

CONCLUSIONS & IMPLICATIONS

This study presents the wide variation of accumulated physical activity minutes when different cut-points are applied to individuals with Down syndrome. There is a critical need to establish Down syndrome-specific measures of physical activity assessment rather than applying methods developed for their peers with typical development.

WHAT THIS PAPER ADDS

This paper highlights concerns over the application of objective measurements of physical activity in youth with Down syndrome from measurement methods derived from populations with typical development. This is the first manuscript to examine this issue in a sample comprised solely of youth with Down syndrome. Results demonstrate the large variation in time spent in each activity intensity that arise due to the application of different cut-point methods.

Effects of physical activity on behaviour and emotional problems, mental health and psychosocial well-being in children and adolescents with intellectual disability: A systematic review

BACKGROUND

This systematic review aimed to explore the effects of sport and physical activity on behaviour and emotional problems, mental health and psychosocial well-being of children and adolescents with intellectual disability.

METHOD

Five databases were searched systematically (ERIC, MEDLINE, PsycINFO, SportDISCUS and SCOPUS), up to 28 February 2021. Thirty-two studies met criteria for inclusion.

RESULTS

Studies in this review included case studies (n = 15), treatment trials (n = 14), cross sectional studies (n = 2) and a cohort study (n = 1). Evidence was positive, though high risk of bias in treatment trials (7 of 14 rated high) meant generalisability of results was limited.

CONCLUSIONS

The available evidence suggests a positive relationship between physical activity and improved behaviour and emotional problems, mental health and psychosocial well-being; however, more robust randomised controlled trials are required to confirm this.

Analysis of developmental trends in physical activity, BMI and muscles in children and adolescents with mild-to-moderate intellectual disability

INTRODUCTION

There is a lack of longitudinal research of physical activity (PA) of pupils with intellectual disability (ID). The aim of the research was to identify the trends in PA, BMI and muscles in children and adolescents with ID in the Czech Republic over 2-year period and find whether 2-month summer holidays have effect on developmental trends. The aim was also to find out the level of PA of children and its correlation with BMI and muscles and the correlation between postural balance and children's muscles.

METHODS

Participants were pupils aged 8-19 (in each measurement was n = 23, n = 37, n = 36, n = 33). They wore a movband for 1 week. InBody analyser and a test of Single leg stance with eyes open were used.

RESULTS

The trend of PA in girls and boys is convex and the trend of their BMI is unbalanced. In pupils with mild and moderate ID, the trend of PA, the trend of BMI and the trend of muscles is unbalanced. Summer holidays cause a decrease in BMI values for all categories. In pupils with moderate ID, summer holidays cause an increase in PA and an increase in muscle (both statistically significant). The correlation between PA and muscle and BMI is ambiguous. Also, the correlation between postural balance and muscles is ambiguous.

CONCLUSIONS

Children's PA reaches 74-122% of the norm. Girls, boys, pupils with mild and moderate ID have normal weight. In the Czech Republic children with ID have many opportunities to participate in sport events during the year.

Feasibility of the Go2Play Active Play intervention for increasing physical and social development in children with intellectual disabilities

Introduction

An active play is designed to increase children’s physical activity levels and fundamental movement skills through outdoor play and is well-suited to the needs of children with intellectual disabilities. However, no active play interventions have included children with intellectual disabilities. This study aims to investigate the feasibility of a school-based active play intervention for children with intellectual disabilities.

Method

Children aged 7–12 years who had intellectual disabilities and were independently ambulatory were eligible. This single-group 17-week intervention was implemented in two additional support needs schools. It consisted of a weekly 1-h active play session incorporating 30 min of structured games and 30 min of free play. Feasibility of recruitment/retention, adherence, and outcome measures were investigated. Outcome measures included school-based physical activity (ActiGraph GT3X+ accelerometer), fundamental movement skills (Test of Gross Motor Development-2), and social interactions (Playground Observation of Peer Engagement). Staff feedback was collected via open-ended questionnaire. Feasibility was investigated using descriptive statistics and questionnaire data analyzed using thematic analysis. Potential pre-post changes were investigated for school-based physical activity, fundamental movement skills, and social interactions using paired samples t tests. The progression criteria were (1) > 50% of eligible participants recruited, (2) > 50% of recruited participants retained, (3) > 50% of active play sessions spent in MVPA, and (4) > 50% of participants complete outcome measurements.

Results

All progression criteria were met. Recruitment and retention rates were 100% (n=21 participants). Intervention adherence was high, based on data from n=1 school, with 90% of participants attending all sessions. Measuring physical activity using accelerometry and fundamental movement skills using the Test of Gross Motor Development-2 were feasible. The Playground Observation of Peer Engagement tool to measure social interactions was not feasible. The only significant increase post-intervention was for social interactions during structured play (pre–post mean difference: –1.46, 95% CI −1.99, −0.93). Staff feedback was positive with the intervention well received by schools and potential benefits post-intervention identified by teachers.

Conclusion

The Go2Play Active Play intervention is feasible for children with intellectual disabilities. Future research should further investigate feasibility and implementation on a larger scale using a pilot cluster randomised controlled trial.

Trial registration

ISRCTN registry: ISRCTN10277566.

Feasibility and applicability of Evenson sedentary behavior cut points applied to children with and without intellectual and developmental disabilities

AIM

Sedentary behavior (SB) is widely studied as it is associated with cardiometabolic health and obesity issues. However, children with Intellectual and Developmental Disabilities (IDD) have been understudied. Accelerometers are commonly used to measure SB in typically developing populations but may be inappropriate for IDD populations due to differences in body movement and physiologic responses to the activity. The use of Evenson sedentary cut-points, created based on typically developing children, has yet to be applied and/or examined in children with IDD.

PURPOSE

A descriptive cross-sectional study was conducted to (1) Assess the feasibility of applying Evenson sedentary cut-points in children with IDD (2) Describe SB over a two-week period between diagnosis groups.

METHODS

The SB of 22 participants (8 children with Down syndrome, 6 children with spina bifida, 8 children with no chronic illness) was assessed on two separate occasions: (1) during a 7-minute sedentary protocol, and (2) over a two-week period.

RESULTS

The study supports the preliminary efficacy of using Evenson cut-points for this population, with 100% of participants being within the Evenson counts per minute (0-100 cpm) during the 7-minute sedentary protocol. The total volume of SB over a two-week period was not significantly different between diagnosis groups (8.8 h, 8.6 h, and 7.1 h of SB for children with Down syndrome, spina bifida, or those with no chronic illness, respectively; p = 0.36).

CONCLUSIONS

Evenson sedentary cut-points can be used for children with IDD. Preliminary data suggest that children with IDD do not engage in significantly different SB than children without a chronic illness. Further study is warranted.Implications for rehabilitationObjective measures of physical activity and sedentary behavior for children with Down syndrome or spina bifida are rarely used due to potential differences in body movement (e.g., gait) during ambulation compared to typically developing peers that may influence the accuracy of cut-points.This study supports that Evenson sedentary cut-points can be used in children with Down syndrome or spina bifida to assess sedentary activity.Preliminary findings from this study demonstrate similarities in patterns of sedentary behaviors exhibited by our sample of children with Down syndrome, spina bifida, or no chronic illness.

Calibration and validation of accelerometry using cut-points to assess physical activity in paediatric clinical groups: A systematic review

Regular physical activity is associated with physiological and psychosocial benefits in both healthy and clinical populations. However, little is known about tailoring the analysis of physical activity using accelerometers to the specific characteristics of chronic conditions. Whilst accelerometry is broadly used to assess physical activity, recommendations on calibration in paediatric clinical groups are warranted. The aim of this systematic review was to provide a critical overview of protocols used to calibrate accelerometry in children and adolescents with clinical conditions, as well as to develop recommendations for calibration and validation of accelerometry in such populations. The search was performed between March to July 2017 using text words and subject headings in six databases. Studies had to develop moderate-to-vigorous intensity physical activity (MVPA) cut-points for paediatric clinical populations to be included. Risk of bias was assessed using a specific checklist. A total of 540,630 titles were identified, with 323 full-text articles assessed. Five studies involving 347 participants aged 9 to 15 years were included. Twenty-four MVPA cut-points were reported across seven clinical conditions, 16 of which were developed for different models of ActiGraph, seven for Actical and one for Tritrac-R3D. Statistical approaches included mixed regression, machine learning and receiver operating characteristic analyses. Disease-specific MVPA cut-points ranged from 152 to 735 counts·15 s-1, with lower cut-points found for inherited muscle disease and higher cut-points associated with intellectual disabilities. The lower MVPA cut-points for diseases characterised by both ambulatory and metabolic impairments likely reflect the higher energetic demands associated with those conditions.

FitSkills: protocol for a stepped wedge cluster randomised trial of a community-based exercise programme to increase participation among young people with disability

INTRODUCTION

There is a need to develop relevant, acceptable initiatives that facilitate physical activity participation in young people with disability. FitSkills was developed to support young people with disability to exercise. The primary aims are to investigate if FitSkills can be scaled up from a small, university-led programme to run as a larger community-university partnership programme, and to determine its effectiveness in improving physical activity participation and health-related quality of life for young people with disability. The secondary aims are to evaluate cost-effectiveness, changes in attitudes towards disability and other health-related outcomes for young people with disability.

METHODS AND ANALYSIS

A stepped wedge cluster randomised trial using a cohort design and embedded health economic evaluation will compare the effect of FitSkills with a control phase. FitSkills matches a young person with disability with a student mentor and the pair exercise together at their local gymnasium for 1 hour, two times per week for 12 weeks (24 sessions in total). One hundred and sixty young people with disability aged 13 to 30 years will be recruited. Eight community gymnasia will be recruited and randomised into four cluster units to have FitSkills introduced at 3-month intervals. Primary (feasibility, participation and health-related quality of life) and secondary outcomes will be collected longitudinally every 3 months from trial commencement, with eight data collection time points in total. The Practical Robust Implementation and Sustainability Model will be used to support knowledge translation and implementation of project findings into policy and practice.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the La Trobe University Human Ethics Committee (HEC17-012), Australian Catholic University (2017-63R), Deakin University (2017-206) and the Victorian Department of Education and Training (2018_003616). Results will be disseminated through published manuscripts, conference presentations, public seminars and practical resources for stakeholder groups.

TRIAL REGISTRATION NUMBER

ACTRN12617000766314.

TRIAL SPONSOR

La Trobe University.

Feasibility of a school-based exercise intervention for children with intellectual disability to reduce cardio-metabolic risk

BACKGROUND

People with intellectual disabilities (ID) are at increased risk of secondary health conditions, reduced quality of life and life expectancy. Children with ID demonstrate low levels of physical activity in association with a higher prevalence of obesity, a modifiable risk factor associated with secondary health conditions including type 2 diabetes and cardiovascular disease. Despite this, physical activity interventions addressing weight and weight-related complications in this population are limited. This study aimed to establish the feasibility of a school-based group exercise intervention for children with moderate to severe ID.

METHODS

A single-arm intervention study was used to establish the feasibility of a 16-week exercise intervention. Children attending a School for Specific Purposes in Sydney, Australia, participated in two 30-min exercise sessions per week across the intervention period in addition to their regular physical education class. Each exercise session was 60% aerobically based, 20% strength based and 20% targeted towards fundamental movement skill development. We used two facilitation strategies to assist the delivery of the intervention, including the implementation of a variety of communication resources and promotion of social interaction. Feasibility was assessed through recruitment rates, program retention, adverse effects, attendance, group size feasibility and non-compliance. Anthropometric measures included height (m), weight (kg) and waist circumference (cm; umbilicus), with body mass index (BMI) and waist-to-height ratios (WtHR) used to determine cardio-metabolic risk. Aerobic capacity was assessed using the submaximal 6-min walk test (6-MWT). Intensity of physical activity sessions was measured through the use of tri-axial accelerometers and compared to physical activity recommendations.

RESULTS

Ten children aged between 9 and 13 years completed the 16-week intervention, with a 55% recruitment rate, 91% program retention, 86% attendance and with no adverse effects reported. Sessions commenced as 1:1 supervisor to child ratios before progressing to established small groups of 2:7 (supervisor : child). Children spent 38.4% (11.5 min) of each session in moderate to vigorous physical activity (MVPA), equating to 20% of their MVPA recommended daily physical activity levels (twice per week). There was a significant change in weight across the intervention period, with a trend towards increased weight between mid-intervention and 3-month follow-up time points. There were no significant changes in child BMI, WtHR or aerobic capacity.

CONCLUSIONS

A school-based group exercise intervention for children with moderate to severe ID is feasible and safe, with high retention rates and physical activity participation. No significant improvements in body composition or aerobic capacity were determined. The present study demonstrates that engaging children with moderate-severe ID in school-based group exercise is feasible to assist in physical activity participation.

Efficacy of custom-fitted footwear to increase physical activity in children and adolescents with Down syndrome (ShoeFIT): randomised pilot study

PURPOSE

To determine the feasibility of conducting a definitive randomised trial to evaluate the efficacy of custom-fitted footwear for increasing physical activity in children and adolescents with Down syndrome.

METHODS

Assessor-blinded, parallel-group randomised pilot study. Thirty-three children and adolescents with Down syndrome were randomly allocated to a custom-fitted footwear group (Clarks^® footwear) or a wait-list control group. Six feasibility domains were evaluated at baseline, 6 and 12 weeks; demand (recruitment), implementation (co-interventions and adherence), acceptability, practicality (adverse events), limited efficacy testing (physical activity, disability associated with foot and ankle problems, and gait parameters), and adaptation (shoe-fit).

RESULTS

Three participants were recruited per month. The use of co-interventions was common with six control group participants purchasing new footwear during the study. Mean adherence was 35 h/week in the custom-fitted footwear group, and there were few minor adverse events. There were trends for differences in physical activity favouring the custom-fitted footwear, but no trends for differences in disability associated with foot and ankle problems or gait parameters. The fit of the custom-fitted footwear was no better than participants' regular footwear.

CONCLUSIONS

A definitive randomised trial is feasible. However, recruitment, use of co-interventions and footwear fit need further consideration.Implications for rehabilitationConducting a definitive randomised trial to determine the efficacy of custom-fitted footwear in increasing physical activity in children and adolescents with Down syndrome is feasible.Custom-fitted footwear may improve physical activity in children and adolescents with Down syndrome.Commercially available footwear may not be suitable for children and adolescents with Down syndrome due to their unique foot shape.

Patterns of objectively measured sedentary behaviour in adults with intellectual disabilities

BACKGROUND

The purpose of this study was to investigate the patterns of objectively measured sedentary behaviour in adults with intellectual disabilities.

METHODS

Baseline accelerometer data were pooled from two randomized controlled trials of lifestyle behaviour change programmes for adults with intellectual disabilities. Patterns of sedentary behaviours were computed including total volume, number, and duration of bouts and breaks.

RESULTS

Participants spent >70% of the day sedentary (8 hr), which was generally accumulated in short sedentary bouts (<10 min). Participants were engaged in significantly more sedentary time during the morning, although differences between time of day were small (mean bout duration range: 19.8-22.3 min).

CONCLUSIONS

The findings add valuable insight into the patterns of sedentary behaviours among adults with intellectual disabilities. Further research investigating the patterns and context of sedentary behaviour is required to develop targeted interventions to reduce total sedentary time in adults with intellectual disabilities.

Calibration of wrist-worn ActiWatch 2 and ActiGraph wGT3X for assessment of physical activity in young adults

BACKGROUND

The validity of Actiwatch 2 in assessing sleep was evident, but its validity in assessing physical activity (PA) level was unknown.

RESEARCH QUESTION

The objective of this study was to validate the wrist-worn Actiwatch 2 and ActiGraph wGT3X as a measurement of PA level against energy expenditure measured by indirect calorimetry.

METHODS

Twenty-seven university students aged 18-26 were recruited from July 2016 to May 2017. They were instructed to run at different speeds (4, 6, 8, 10, and 12 km/h) on a treadmill, each speed for 10 min. Oxygen consumption and carbon dioxide production of the subjects was measured by indirect calorimetry using the Cosmed K4b² gas analyzer. Each subjects wore a single pair of accelerometers (Actiwatch 2 and ActiGraph wGT3X) on both wrists.

RESULTS

All the accelerometers were strongly correlated (ρ=0.83-0.94, all p-values <0.001), and all four accelerometers were strongly correlated with the METs obtained from the Cosmed K4b² (ρ=0.72-0.74, all p-values <0.001). Regression analysis showed that the non-dominant wrist-worn Actiwatch 2 cutoff cpm for moderate and vigorous PA were 399 and 1,404, respectively; for the ActiGraph wGT3X-BT the corresponding cutoffs were 4,514 and 15,044, respectively. The goodness-of-fit of the MET prediction equations were all >75%. When classifying the activities as either sedentary, light activity, moderate-intensity activity, or vigorous-intensity activity using the MET prediction equations, the agreements between the four accelerometers and that by the Cosmed K4b² were high, all AUCs were above 80% except those of the Actiwatch worn on the left (non-dominant) wrist. The Bland-Altman plots show that, for all four accelerometers, the biases were close to zero and error variances were largest when the mean measurements were around 6 METs.

SIGNIFICANCE

We showed that wrist-worn Actiwatch 2 and ActiGraph wGT3X-BT were strongly correlated in PA assessment.

Segmenting accelerometer data from daily life with unsupervised machine learning

Purpose

Accelerometers are increasingly used to obtain valuable descriptors of physical activity for health research. The cut-points approach to segment accelerometer data is widely used in physical activity research but requires resource expensive calibration studies and does not make it easy to explore the information that can be gained for a variety of raw data metrics. To address these limitations, we present a data-driven approach for segmenting and clustering the accelerometer data using unsupervised machine learning.

Methods

The data used came from five hundred fourteen-year-old participants from the Millennium cohort study who wore an accelerometer (GENEActiv) on their wrist on one weekday and one weekend day. A Hidden Semi-Markov Model (HSMM), configured to identify a maximum of ten behavioral states from five second averaged acceleration with and without addition of x, y, and z-angles, was used for segmenting and clustering of the data. A cut-points approach was used as comparison.

Results

Time spent in behavioral states with or without angle metrics constituted eight and five principal components to reach 95% explained variance, respectively; in comparison four components were identified with the cut-points approach. In the HSMM with acceleration and angle as input, the distributions for acceleration in the states showed similar groupings as the cut-points categories, while more variety was seen in the distribution of angles.

Conclusion

Our unsupervised classification approach learns a construct of human behavior based on the data it observes, without the need for resource expensive calibration studies, has the ability to combine multiple data metrics, and offers a higher dimensional description of physical behavior. States are interpretable from the distributions of observations and by their duration.

Physical activity levels of children and adolescents with moderate-to-severe intellectual disability

Background

Regular participation of children and adolescents with intellectual disabilites in physical activity is important to maintain good health and to acquire motor skills. The aim of this study was to investigate the habitual physical activity in these children.

Methods

Sixty‐eight children and adolescents (2–18 years) with a moderate‐to‐severe intellectual disability were included in the analyses. They wore an accelerometer on eight consecutive days. Data was analysed by use of descriptive statistics and multiple linear regression analyses.

Results

The participants took on average 6,677 ± 2,600 steps per day, with intensity of 1,040 ± 431 counts per minute. In total, 47% of the participants were meeting physical activity recommendations. Low motor development was associated with low physical activity.

Conclusions

As more than half of the participants were not meeting the recommendations, family and caregivers of these children should focus on supporting and motivating them to explore and expand their physical activities.

The lifestyle behaviours of young adults with intellectual disabilities as they transition from school to adulthood: A pilot and feasibility study

BACKGROUND

In the general population, the transition from adolescence to adulthood has been identified as a "high-risk" period for weight gain. There has been no research examining health behaviours over this transition in adults with intellectual disabilities.

METHODS/DESIGN

The feasibility of recruitment, retention and relevant health behaviours were measured in 31 adolescents with mild-moderate intellectual disabilities. Anthropometric, objective physical activity, dietary and self-determination measures were collected over a 12-month transitional period from school to adulthood.

RESULTS

Key results suggest weight and BMI increased significantly from month 6 to month 12 (p = 0.044 and p = 0.043). Waist circumference increased significantly from baseline to month 12 (p = 0.049), and from month 6 to month 12 (p = 0.03).

DISCUSSION

Recruiting and retaining young adults with intellectual disabilities over a 12-month health behaviour study is feasible. The data indicate the transition from school to adulthood may be the start of a high-risk period for weight gain.

A systematic review and meta-analysis of interventions to increase physical activity in children and adolescents with intellectual disabilities

BACKGROUND

Increasing physical activity (PA) through intervention can promote physical and mental health benefits in children and adolescents. However, children and adolescents with intellectual disabilities (ID) have consistently been shown to engage in low levels of PA, which are insufficient for long-term health. Despite this, little is known about the effectiveness of interventions to increase PA in children and adolescents with ID. The aims of this study were therefore to systematically review how effective interventions are at increasing PA levels in children and adolescents with ID and to further examine what components have been used in these interventions.

METHOD

A systematic search of MEDLINE, EMBASE, Education Resources Information Center, Cumulative Index to Nursing and Allied Health Literature, PsychINFO, Cochrane Central Register for Controlled Trials and International Standard Randomised Controlled Trial Number trials registry was conducted (up to July 2016). Articles were included if they met the following eligibility criteria: children and adolescents (<18 years) with ID, measurement of PA at baseline and post-intervention and intervention studies. Effect sizes were calculated as standardised mean difference (d) and meta-analysis calculated between intervention and no treatment control intervention.

RESULTS

Five studies met the eligibility criteria and were included in the review. Study design, methodological quality and intervention components were varied. Interventions did not support sufficient changes in PA to improve health. The meta-analysis demonstrated that intervention groups were not more effective at increasing PA levels post-intervention (d: 2.20; 95% CI -0.57 to 0.97) compared with control. However, due to a decrease in PA in the control intervention, a moderate significant effect was demonstrated at follow-up (d: 0.49; 95% CI 0.14 to 0.84).

CONCLUSIONS

There is a lack of studies which aim to increase PA levels in children and adolescents with ID, with current interventions ineffective. Future studies are required before accurate recommendations for appropriate intervention design and components can be made.

A Pilot Study to Determine the Consistency of Simultaneous Sleep Actigraphy Measurements Comparing All Four Limbs of Patients with Parkinson Disease

Wrist actigraphy is a form of objective sleep measurement that has gained a central role in sleep research and clinical settings. Guidelines for actigraphy recommend placing the monitor on the non-dominant wrist, however, this potentially will be the most involved limb for someone with Parkinson disease, and so alternative placement would be preferred. To-date, there is little published about sleep actigraphy use in Parkinson disease (PD). This study examines the degree of sleep actigraphy score variation in persons with PD when monitors are placed simultaneously on all four limbs. In this study, four participants wore a sleep actigraph on each limb for seven nights. Data from the four actigraphs was compared within each participant to determine the degree of consistency. We found that all of the participants’ sleep efficiency and total sleep time scores were higher in the lower limb than upper limb. There was no notable difference in sleep variables between the dominant arm and non-dominant arm. We concluded that simultaneous actigraphy measurement did not notably vary between dominant and non-dominant arms. However, a discrepancy was seen between upper limbs and lower limbs actigraph scores. Further study is warranted to develop guidelines for sleep actigraphy use in this population.