The age range of participants encompassed 3 months to 20 years, with a higher proportion of males to females. All studies excluded participants who had other physical disabilities or health conditions that would impact PA levels. Four studies used children developing typically as a comparator.19–21 , 24 Six studies also compared participant outcomes to PA guidelines of at least 60 minutes of moderate to vigorous PA per day17–20 , 22 , 23; 1 study used a guideline of 30 minutes of moderate PA per day.21
When tracking activity levels, 7 studies used accelerometers for activity tracking over 7 days17–23 while 1 study tracked activity for 48 hours once a month over the span of 4 months.24 One study used the Actical worn on the hip set to 15-second epoch18; 2 studies used the ActiGraph worn on the lower back set to 2-second17 and 10-second23 epochs, respectively; 2 studies used the ActiTrainer worn on the hip set to 15-second epochs19 , 20; 1 study used the RT3 worn on the waist set to 1-minute epoch22; 1 used the Actitrac worn on the waist set to 30-second epoch21; and 1 study used the Actiwatch worn on the ankle set to 15-second epoch.24 Participants in all studies were instructed to wear the activity monitors for all activities except for water-based activities, as well as for sleeping in 6 studies. Requirements for inclusion in data analysis ranged from no defined minimum wearing time to at least 8 to 10 hours per day and for at least 3 to 6 days. Cut points for determining intensity of activity varied greatly across all studies.
Results from the assessment of quality are shown in Table 2. Most of the studies (5 of the 8) fell into the “fair” category,18 , 20 , 22–24 with 2 rated as “good”17 , 21 and 1 as “poor.”19 Studies tended to be strong in the reporting category, but were weaker in the internal and external validity categories. In particular, studies tended to lose points due to issues with blinding (participants could not be blinded to the fact that they were wearing an accelerometer, and the act of wearing it may have influenced their activity level), recruitment (samples were not likely to be representative), and confounding (lack of randomization).
Table 3 presents results in more detail. The overarching results of the full-text review supported that children with DS are not meeting the recommended PA guidelines of at least 60 minutes of moderate to vigorous PA daily. Four of the studies, including the longitudinal studies, found younger children with DS engaged in more PA of higher intensity than older children.17 , 18 , 23 , 24 In 6 of the 7 studies that investigated PA guidelines, the percentage of participants with DS meeting activity guidelines ranged from 0% to 43%.17–20 , 22 , 23 The study by Whitt-Glover et al21 reported up to 93% of children participating in at least 60 minutes per day of moderate PA and 40% in vigorous PA, but this included both children with DS and children developing typically and the cut points used were much lower than those of the other studies. Two studies found that no participants engaged in vigorous PA of 20 continuous minutes.21 , 22 The longitudinal study by Izquierdo-Gomez et al23 also found that those participants who met PA guidelines at the baseline measurement showed a greater decline in activity levels over the 2 follow-up years while those participants who did not meet guidelines at baseline maintained their activity levels. No significant difference was found between activity levels during the week versus weekend or between during school versus after school.17 In addition, the only differences found between males and females was males were more active than females during the weekend17 and engaged in more vigorous PA over a 2-year follow-up.23 For those studies with control groups, 3 found that children with DS engaged in less vigorous PA,19–21 and 2 found that children with DS engaged in more light PA and less sedentary and moderate PA than the children in the control group.19 , 20 One study found that infants with DS, while as active as their peers who were developing typically, engaged in low intensity activities for longer periods during the day at 3, 4, and 6 months of age and had different motor activity patterns from 4 to 6 months of age.24
This review provides objective information on the PA levels of children with DS. Although there are limitations due to the nature of the included studies, it provides important insight into the current activity levels that can inform future research and efforts to increase PA levels of children with DS.
Overall, studies found that children with DS are not reaching recommended guidelines of 60 minutes of moderate to vigorous PA each day. In addition, studies found that PA, particularly more intense PA, tended to decrease with age while sedentary time tended to increase. Furthermore, in studies that included a control of children with typical development, children with DS tended to engage in more light-intensity PA than moderate or vigorous PA as compared with the controls developing typically. This is concerning, not only because children with DS are at risk for health conditions for which PA can have a positive effect (eg, obesity),6 , 7 but also because decreased physical fitness in this population has been found to result in functional activity impairments.25 Individuals with DS spent less time in a sedentary state than controls who were developing typically. Although studies did not provide a reason for this trend, several possibilities exist. For example, controls developing typically may be spending more time seated completing school and homework. Alternatively, individuals with DS may be more restless, given that individuals with DS have higher rates of psychiatric and behavioral disorders, including attention-deficit hyperactivity disorder, than other children.2 , 26 As individuals with DS are inclined to move, but are engaging in less moderate to vigorous PA, it is important to investigate barriers to participation in PA and to consider efforts to promote increased levels of higher intensity PA.
The control group participants were not meeting PA guidelines. This agrees with a study that examined activity levels of US youth with accelerometers,27 and the most recent US Report Card on Physical Activity for Children and Youth.28 This supports a growing awareness that a further increase of PA and a decrease of barriers to PA participation may need to be incorporated into the daily lives of all children.
While this review provides insight into the PA levels of children with DS based on objective, accelerometer data, there are limitations to the review that impact conclusions. Included studies varied in accelerometers and epochs used as well as the cut points for activity intensity levels. Using different epochs and different cut points can result in different classifications of activity level. Furthermore, cut points used in these studies often were based on cut points suggested for children developing typically. Given that children with DS can have related cardiovascular and musculoskeletal impairments,2 , 3 these cut points may not reflect the true activity intensity level for children with DS, possibly resulting in an underestimation of time engaged in moderate to vigorous PA. That is, children with DS may be engaging in more intense activity than children developing typically at the same accelerometer counts because impairments associated with DS may make movement less efficient.3
In addition to these limitations based on data collection and analysis, there are limitations related to influences on activity due to wearing the accelerometer. The accelerometers provide an objective measure of PA throughout the day, reducing the risk of bias associated with self-report measures. However, children (and their parents) knew their activity was being monitored, so this may have altered their normal activity levels leading to bias. If children are bothered by the accelerometer, they may engage in less activity. Conversely, knowing that activity is being monitored, children may make more effort to engage in PA during that time and/or their parents may encourage more activity during that time. In this case, PA levels may be overestimates of habitual activity.
Finally, recruitment efforts in these studies may have resulted in study populations that were not representative of the general DS pediatric population. In particular, parents who have a strong belief in the importance of PA and/or who encourage their children to engage in higher levels of PA may have been more inclined to volunteer for these studies. No indication was given as to what, if any, prior physical therapy and other rehabilitative services the children may have received. It is conceivable that those children who received more services before the studies might have higher levels of PA. As a result, these studies may have overestimated the amount of PA typical of children with DS in the broader population. There may have been overlap in participants in some included studies, thus affecting representativeness. The Izquierdo-Gomez et al studies,17 , 23 due to the longitudinal design, reported on PA levels for the same cohort at different time points. In addition, the Matute-Llorente et al studies,19 , 20 given their similar timeframe and recruitment strategies, may have reported on data from the same cohort of participants. However, it is not clear from the articles whether these were in fact 1 cohort or 2 separate cohorts. As a result, although 8 studies are included, they may only represent 6 distinct groups of participants, which could further limit generalizability.
The limitations described earlier are important to consider and suggest areas for further research. While PA may have been overestimated due to the nature of wearing a device to monitor activity and/or the representativeness of the sample, overall, children with DS were not meeting PA guidelines. However, activity level cut points may have underestimated the actual intensity at which these children engaged in activity. Appropriate cut points should be determined for children with DS to ensure that conclusions about the time spent in moderate to vigorous PA are accurate. Despite these limitations, these studies suggest that efforts should continue to promote more PA in children with DS and to reduce barriers for this population to engage in PA so that they can build healthy activity habits that will carryover as they age.
The results of this review suggest children with DS are engaging in less PA than their peers who are developing typically and are not meeting PA guidelines across age groups, with intensity of activity levels declining as children enter adolescence. However, the majority of studies only had “fair” quality and varied greatly in determination of intensity levels of activity, indicating a need for further research. Regardless, noted decline and lack of more vigorous PA poses functional and general health risks for this population. Areas for future research include validation and standardization of cut points for children with DS and analysis of characteristics of activity levels, both throughout the day and across the lifespan. Future research should examine the effect of early physical therapy and explore the potential benefits of physical therapy across the lifespan on PA and on neuromusculoskeletal issues characteristic of DS known to affect PA (eg, alignment, posture, muscle tone, strength, endurance, and cardiorespiratory fitness). Focused study of times of increased risk and vulnerability and times of transition characterized by decreased PA and participation will be important, as well as studying how increasing PA impacts the health and well-being of children with DS.
We would like to thank Leila Ledbetter, MLIS, for her assistance with this project.
1. de Graaf G, Buckley F, Skotko BG. Estimation of the number of people with Down syndrome
in the United States. Genet Med. 2017;19(4):439–447. doi:10.1038/gim.2016.127.
2. Roizen NJ, Patterson D. Down's syndrome. Lancet. 2003;361(9365):1281–1289. doi:10.1016/S0140-6736(03)12987-X.
3. Pitetti K, Baynard T, Agiovlasitis S. Children and adolescents with Down syndrome
, physical fitness and physical activity
. J Sport Health Sci. 2013;2(1):47–57. doi:10.1016/j.jshs.2012.10.004.
4. Cioni M, Cocilovo A, Rossi F, et al Analysis of ankle kinetics during walking in individuals with Down syndrome
. Am J Ment Retard. 2001;106(5):470–478. doi:10.1352/0895-8017(2001)106<0470:AOAKDW>2.0.CO;2.
5. Mik G, Gholve PA, Scher DM, Widmann RF, Green DW. Down syndrome
: orthopedic issues. Curr Opin Pediatr. 2008;20(1):30–36. doi:10.1097/MOP.0b013e3282f35f19.
6. Janssen I, Leblanc AG. Systematic review of the health benefits of physical activity
and fitness in school-aged children and youth. Int J Behav Nutr Phys Act. 2010;7:40. doi:10.1186/1479-5868-7-40.
7. US Department of Health and Human Services. Physical Activity
Guidelines Advisory Committee Report. Washington, DC: US Department of Health and Human Services; 2008.
8. Loprinzi PD, Lee IM, Andersen RE, Crespo CJ, Smith E. Association of concurrent healthy eating and regular physical activity
with cardiovascular disease risk factors in US youth. Am J Health Promot. 2015;30(1):2–8. doi:10.4278/ajhp.140213-QUAN-71.
9. Kriska A, Delahanty L, Edelstein S, et al Sedentary behavior and physical activity
in youth with recent onset of type 2 diabetes. Pediatrics. 2013;131(3):e850–e856. doi:10.1542/peds.2012-0620.
10. US Department of Health and Human Services. 2008 Physical Activity
Guidelines for Americans. Washington, DC: US Department of Health and Human Services; 2008.
11. Yang CC, Hsu YL. A review of accelerometry-based wearable motion detectors for physical activity
monitoring. Sensors (Basel). 2010;10(8):7772–7788. doi:10.3390/s100807772.
12. Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. J Clin Epidemiol. 2009;62(10):1006–1012. doi:10.1016/j.jclinepi.2009.06.005.
13. Downs SH, Black N. The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. J Epidemiol Community Health. 1998;52(6):377–384.
14. Deeks JJ, Dinnes J, D'Amico R, et al Evaluating non-randomised intervention studies. Health Technol Assess. 2003;7(27):1–173.
15. Simic M, Hinman RS, Wrigley TV, Bennell KL, Hunt MA. Gait modification strategies for altering medial knee joint load: a systematic review. Arthritis Care Res (Hoboken). 2011;63(3):405–426. doi:10.1002/acr.20380.
16. O'Connor SR, Tully MA, Ryan B, Bradley JM, Baxter GD, McDonough SM. Failure of a numerical quality assessment scale to identify potential risk of bias in a systematic review: a comparison study. BMC Res Notes. 2015;8:224. doi:10.1186/s13104-015-1181-1.
17. Izquierdo-Gomez R, Martínez-Gómez D, Acha A, et al Objective assessment of sedentary time and physical activity
throughout the week in adolescents with Down syndrome
. The UP&DOWN study. Res Dev Disabil. 2014;35(2):482–489. doi:10.1016/j.ridd.2013.11.026.
18. Esposito PE, MacDonald M, Hornyak JE, et al Physical activity
patterns of youth with Down syndrome
. Intellect Dev Disabil. 2012;50(2):109–119. doi:10.1352/1934-9556-50.2.109.
19. Matute-Llorente A, González-Agüero A, Gómez-Cabello A, Vincente-Rodríguez G, Casajús GA. Decreased levels of physical activity
in adolescents with down syndrome
are related with low bone mineral density: a cross-sectional study. BMC Endocr Disord. 2013;13:22. doi:10.1186/1472-6823-13-22.
20. Matute-Llorente A, González-Agüero A, Gómez-Cabello A, Vincente-Rodríguez G, Casajús GA. Physical activity
and cardiorespiratory fitness in adolescents with Down syndrome
. Nutr Hosp. 2013;28(4):1151–1155. doi:10.3305/nh.2013.28.4.6509.
21. Whitt-Glover MC, O'Neill KL, Stettler N. Physical activity
patterns in children with and without Down syndrome
. Pediatr Rehabil. 2006;9(2):158–164. doi:10.1080/13638490500353202.
22. Shields N, Dodd KJ, Abblitt C. Do children with Down syndrome
perform sufficient physical activity
to maintain good health? A pilot study. Adapt Phys Activ. 2009;26(4):307–320. doi:10.1123/apaq.26.4.307.
23. Izquierdo-Gomez R, Martínez-Gómez D, Esteban-Cornejo I, et al Changes in objectively measured physical activity
in adolescents with Down syndrome
: the UP&DOWN longitudinal study. J Intellect Disabil Res. 2017;61(4):363–372. doi:10.1111/jir.12354.
24. McKay SM, Angulo-Barroso RM. Longitudinal assessment of leg motor activity and sleep patterns in infants with and without Down syndrome
. Infant Behav Dev. 2006;29(2):153–168. doi:10.1016/j.infbeh.2005.09.004.
25. Cowley PM, Ploutz-Snyder LL, Baynard T, et al Physical fitness predicts functional tasks in individuals with Down syndrome
. Med Sci Sports Exerc. 2010;42(2):388–393. doi:10.1249/MSS.0b013e3181b07e7a.
26. Oxelgren UW, Myrelid Å, Annerén G, et al Prevalence of autism and attention-deficit-hyperactivity disorder in Down syndrome
: a population-based study. Dev Med Child Neurol. 2017;59(3):276–283. doi:10.1111/dmcn.13217.
27. Troiano R, Berrigan D, Dodd K, Mâsse L, Tiltert T, McDowell M. Physical activity
in the United States measured by accelerometer
. Med Sci Sports Exerc. 2008;40(6):181–188. doi:10.1249/mss.0b013e31815a51b3.
28. National Physical Activity
Plan Alliance. 2016 United States Report Card on Physical Activity
for Children and Youth. Columbia, SC: National Physical Activity
Plan Alliance; 2016.
accelerometer; Down syndrome; pediatric; physical activity
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