CONTEXT:

The World Health Organization recommends tummy time for infants because of the benefits of improved motor development and reduced likelihood of plagiocephaly. Because of poor uptake of these recommendations, the association of tummy time with other health outcomes requires further investigation.

OBJECTIVE:

To review existing evidence regarding the association of tummy time with a broad and specific range of infant health outcomes.

DATA SOURCES:

Electronic databases were searched between June 2018 and April 2019.

STUDY SELECTION:

Peer-reviewed English-language articles were included if they investigated a population of healthy infants (0 to 12 months), using an observational or experimental study design containing an objective or subjective measure of tummy time which examined the association with a health outcome (adiposity, motor development, psychosocial health, cognitive development, fitness, cardiometabolic health, or risks/harms).

DATA EXTRACTION:

Two reviewers independently extracted data and assessed their quality.

RESULTS:

Sixteen articles representing 4237 participants from 8 countries were included. Tummy time was positively associated with gross motor and total development, a reduction in the BMI-z score, prevention of brachycephaly, and the ability to move while prone, supine, crawling, and rolling. An indeterminate association was found for social and cognitive domains, plagiocephaly, walking, standing, and sitting. No association was found for fine motor development and communication.

LIMITATIONS:

Most studies were observational in design and lacked the robustness of a randomized controlled trial. High selection and performance bias were also present.

CONCLUSIONS:

These findings guide the prioritization of interventions aimed at assisting parents meet the global and national physical activity guidelines.

In 1992, the American Academy of Pediatrics recommended that infants be placed supine to sleep.1  This was due to the high incidence of sudden infant death syndrome (SIDS) caused from prone sleeping.1  This became known as the Back to Sleep campaign, which contributed to a 40% decrease in SIDS incidence in the United States.2  However, although the incidence of SIDS was reduced, infants placed supine to sleep had slower achievement of their motor milestones3,4  and an increased occurrence of head-shape abnormalities.5  To counteract these effects, parents were encouraged to provide their infants with tummy time.6  Tummy time is a form of physical activity recommended for infants <6 months of age. It is defined as awake prone positioning on the floor that is encouraged and supervised by an adult.7  Because studies have demonstrated a positive association between tummy time and gross motor development,812  tummy time is a component of the national movement guidelines in Australia, the United Kingdom, Canada, and South Africa.1316  It is also a component of the guidelines from the National Academy of Medicine17  and the American Academy of Pediatrics18 ; and is included in the World Health Organization global guidelines for physical activity, sedentary behavior, and sleep for children <5 years of age.19  Thirty minutes of tummy time spread over a 24-hour period is recommended to optimize healthy growth and development.

Evidence shows that only ∼30% of parents and 75% of child care educators adhere to these recommendations.20,21  The potential benefits of tummy time outlined in the current physical activity guidelines include the effect of tummy time on an infant’s gross motor development. Whereas, the effects of tummy time on individual aspects of motor development are not currently highlighted. Research in which the association of tummy time with specific aspects of motor development (such as the ability to move while prone, including the ability to roll, sit, or walk) is investigated has not yet been systematically reviewed. Additionally, the association of tummy time with other infant health outcomes, such as adiposity, psychosocial health, cognitive development, fitness, and cardiometabolic health, is currently unknown because current evidence regarding tummy time interventions is focused primarily on motor development and head shape.2123  A previous review investigating the effect of tummy time on other infant health outcomes has been conducted.24  However, to be included in this systematic review, the minimum sample size was 100 participants for observational studies. As such, only 2 studies were found relating to tummy time. One study revealed a positive effect on motor development,23  and the other study revealed a protective effect against deformational plagiocephaly.25  Some of the health benefits that may be present in other smaller studies may be a decrease in BMI in older children, fine motor skill development, cardiovascular fitness, bone mineral density, and a reduction in other head-shape abnormalities such as brachycephaly.

The early years are a crucial period of physical, cognitive, social, and emotional development.24,26  Identifying the association of tummy time with specific aspects of motor development as well as other health outcomes is important for the development of evidence-based interventions and may assist parents and educators in meeting the recommended guidelines of 30 minutes per day. Our purpose for this systematic review was to determine the association of tummy time with infant health outcomes across experimental and observational study designs.

A systematic review of the literature was undertaken on the association of tummy time with infant health outcomes. It was prospectively registered with PROSPERO, the International Prospective Register of Systematic Reviews (http://www.crd.york.ac.uk/prospero; identifier CRD42017075156) and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.27 

Computerized searches of databases were completed in May 2018 and May 2019 by using Medline, Cumulative Index to Nursing and Allied Health Literature, Scopus, and PsycINFO. The search was limited to titles and abstracts containing “all infant (birth to 23 months)” and English and humans. The Scopus search strategy was as follows: (TITLE-ABSKEY((“tummy time” OR tummy OR prone OR position* OR abdomen OR stomach OR belly OR front)) AND TITLEABS-KEY(effect* OR result* OR influence* OR impression* OR appear* OR achieve* OR consequence* OR outcome* OR conclusion* OR correlat* OR determin* OR predictor* OR relationship* OR associate* OR difference*) AND TITLE- ABS-KEY((infant* OR baby OR babies OR newborn))) AND (LIMIT-TO(DOCTYPE,”ar”) OR LIMIT-TO(DOCTYPE,”re”) OR LIMIT- TO(DOCTYPE,”ip”)) AND (LIMIT TO(EXACTKEYWORD,”Human”) OR LIMIT TO(EXACTKEYWORD,”Humans”)) AND (LIMIT- TO(LANGUAGE,”English”)). The following search terms (keywords) were used: “tummy time” OR “tummy” OR “prone” OR “position*” OR “abdomen” OR “stomach” OR “belly” OR “front” AND “effect*” OR “result*” OR “influence*” OR “impression*” OR “appear*” OR “achieve*” OR “consequence*” OR “outcome*” OR “conclusion*” OR correlat* OR determin* OR predictor* OR relationship* OR associat* OR difference* OR investig*. Duplicates were removed by using EndNote software, and the search output was screened manually also by using EndNote. After duplicates were removed, two researchers independently reviewed the titles of the articles to determine if they met the criteria for inclusion. Abstracts and full-text articles were then studied to clarify and confirm eligibility. Any differences between reviewers were discussed to reach consensus regarding inclusion. Reference lists of relevant reviews identified during screening were also checked for relevant studies. To capture registered clinical trials, two trial registries (https://clinicaltrials.gov/ and http://www.who.int/ictrp/en/) were searched in May 2018 and May 2019 by using the search term “tummy time” and the infant age group.

To be included in this review, the article was required to be peer-reviewed, be published or in press, be written in English, and meet the predetermined study criteria (see Supplemental Information). The review was based on the population, intervention or exposure, comparator or control, and outcome study criteria28  from the Grading of Recommendations Assessment, Development, and Evaluation framework.29,30  Conference abstracts, book chapters, and dissertations were excluded.

The population chosen to review was apparently healthy (ie, general population) infants aged from 0 to 12 months old. Studies that only included children with a diagnosed medical condition (eg, Down syndrome), with the exception of studies relating to prematurity, SIDS, or low birth weight, were excluded. If an age range was described rather than the mean age, infants up to 12 months of age were included. If a mean age or age range was not reported, participants who were described as infants and newborns were included. For longitudinal or experimental studies, the age criterion is unlimited for the outcome measures; however, the intervention must have taken place while the infant was between the ages of 0 and 12 months old. Experimental and observational studies were required to have a minimum sample size of 15 (in 1 intervention group) and 30 participants, respectively.

The interventions comprised different durations, frequencies, patterns, types, and intensities of tummy time and/or prone positioning when awake. Tummy time was defined as awake and supervised prone positioning. Prone positioning ability was defined as an infant’s ability to move their body when placed on their stomach. This could include the ability to roll from front to back, the ability to lift their head, the ability to push up with their arms, and the ability to move their arms and/or legs.31  Studies in which only prone positioning during prone sleeping was investigated were excluded. Tummy time and/or prone positioning ability could be measured objectively (eg, accelerometer, direct observation) or subjectively (eg, proxy report). For experimental studies, interventions targeting tummy time and/or prone positioning exclusively were included. Interventions targeting multiple health behaviors (eg, tummy time and breastfeeding) were not included to avoid over- or underreporting the effect of tummy time on an infant health outcome from a combined intervention.

The comparators were objective (eg, accelerometer) or subjective (eg, proxy report, questionnaire) measures of tummy time and/or prone positioning ability from an observational or experimental study.

The outcomes were various health outcomes; for example, adiposity (eg, overweight, obesity, BMI), motor development (eg, gross motor skills, fine motor skills, specific components of a motor skill, locomotor and object control skills), psychosocial health (eg, self-efficacy, self-esteem, prosocial behavior, social functioning, depressive symptoms, anxiety symptoms), cognitive development (eg, language development, attention, executive functioning), fitness (eg, cardiovascular fitness, musculoskeletal fitness), bone and skeletal health (eg, bone mineral density, bone mineral content, skeletal area, vitamin D), cardiometabolic health (eg, blood pressure, insulin resistance, blood lipid levels), and risks and/or harms (eg, injury, plagiocephaly).

Data extracted included authors’ names, publication year, country, study design, sample size, characteristics of participants, tummy time measure, health outcome measure, type of health outcome, association of tummy time with an infant health outcome, and the risk of bias. A finding was deemed to be statistically significant if P <.05. Two reviewers completed data extraction for each included article and cross-checked the findings.

Risk of bias was assessed at the individual study level by using the Cochrane risk of bias assessment for observational and intervention studies.32  Selection bias, performance bias, selective reporting bias, detection bias, attrition bias, and other biases (eg, inadequate control for key confounders) were assessed.33  For all studies, risk of bias was assessed independently by both reviewers and then confirmed to ensure consistency. Overall quality of evidence was evaluated by 1 reviewer and verified by the larger review team.

After duplicates were removed, 4233 titles, 790 abstracts, and 130 full-text articles were screened (see Fig 1). A total of 16 articles met the inclusion criteria. Reasons for excluding articles are summarized in Fig 1. The 16 articles involved 4237 participants from 8 different countries. The year of publication ranged from 1998 to 2018. An experimental study design was used in 1 article34 ; this was a nonrandomized intervention (n = 1). Observational study designs were used in the remaining 15 articles, 3,8,9,23,25,3541 which included longitudinal (n = 8) and cross-sectional (n = 7) studies.

Tummy time was measured subjectively in all 16 included articles by using a questionnaire or parent interview (n = 12) or a position log or diary (n = 4). Parents were asked to record or describe the amount of time their infant spent in tummy time (hours or minutes per day) in 8 studies, to report the number of times per day spent in tummy time in 7 studies, to report the number of experiences spent in a prone position when awake in 3 studies, to outline their infant’s preferred position in which to be awake and play in 2 studies, to identify the age at which the infant started tummy time in 2 studies, and to report their infant’s ability to move while prone in 1 study. Motor development was assessed as the health outcome of interest in 12 studies,3,8,9,23,34,36,3941  head shape in 3 studies,25,35,37  BMI in 1 study,36  and cognition in 1 study.38  The most common assessments for motor development were the Alberta Infant Motor Scale (AIMS) and the Peabody Developmental Motor Scale, which were each used in 5 studies. Further information on the study design, sample size, tummy time outcome measure, and association of tummy time with the health outcome is summarized in Table 1.

The quality of included studies ranged from low to high. All studies had high selection bias due to homogenous participants in each of the studies. Most studies relied on unvalidated questionnaires or position logs to measure the amount of tummy time the infant received. However, the majority of studies used a validated tool to measure the health outcome and had <20% of participants drop out from the studies. Further information regarding risk of bias of the included studies is reported in Tables 2 and 3. Rules for classifying the strength of tummy time and a summary of the association of tummy time31  with health outcomes are reported in Tables 4 and 5 respectively.

All outcomes that had a positive, neutral, or negative association with tummy time are reported in Tables 1 and 5. In general, there were 5 health and development outcomes examined, including head shape, motor development, BMI, social communication, and cognition. When separating these outcomes into more specific components, there were 16 health and development outcomes found, including brachycephaly; plagiocephaly; gross motor development; fine motor development; total development; ability to move while prone or supine, including sitting, standing, rolling, crawling, and walking; personal and/or social communication; BMI; and cognition (Table 5).

Experience in tummy time was found to have a significant positive association with an infant’s total development (communication, gross motor and fine motor development, problem-solving, and social skills), gross motor development, the ability to move while prone, supine, rolling, and crawling; a decrease in the BMI z score (BMI-z); and the prevention of brachycephaly. Seventeen positive associations of tummy time with an infant’s gross motor development were found in 7 different studies, 26 positive associations of tummy time with an infant’s ability to move while prone were found in 6 different studies, 6 positive associations of tummy time with an infant’s ability to crawl were found in 2 different studies, and 4 positive associations of tummy time with an infant’s ability to move while supine were found in 2 different studies. Indeterminate associations were found between tummy time and plagiocephaly; the ability to sit, stand, and walk; cognition; and personal and/or social domains. No association was found between tummy time and fine motor development and communication.

Head Shape

The authors of 3 studies examined the association between tummy time and head shape. Plagiocephaly and brachycephaly are defined as flattening of the side and back of the skull by external forces, respectively.42,43  There was a significant decrease in brachycephaly scores (P < .01) associated with more hours per day prone on the floor when awake, but there was no association with plagiocephaly scores (P > .05).35  Another study did not reveal an association between length of tummy time and plagiocephaly (P = .83).37  However, it was found that infants who received tummy time <3 times per day were at greater risk to develop plagiocephaly at 7 weeks of age (P = .02).25 

Motor Development

The association between physical activity and motor development was examined in 12 studies. Eleven studies revealed a positive effect, and 1 study revealed a neutral effect. One nonrandomized controlled trial revealed that infants <6 months old who had tummy time routinely (more than once per day) had significantly higher locomotion scores than other infants in the youngest group who were seldom placed prone to play (P = .0012) or who were placed prone less than once per day (P = .0367).34  Authors of the 4 longitudinal studies reported a significant difference between prone and nonprone infants in gross motor development (P < .001)41 ; achievement of rolling, crawling on abdomen, crawling on fours, and sitting earlier (P < .0167)23 ; achievement of prone developmental milestones (P < .01)36 ; and earlier attainment of supported sitting, sitting unsupported, crawling, and pulling to stand (P < .05).3  Interestingly, in one of these studies, the gain in motor development persisted until the child was 3 years of age (P = .001).41  The 6 observational studies also revealed that infants who spent more time awake in a prone position achieved their expected milestones earlier (P < .001)9  and had higher AIMS percentile and prone scores (P < .01)10,11,40  compared with infants who spent less time awake in a prone position. Spending >30 minutes per day in tummy time was associated with a significantly greater ability in prone head control (P < .0001), active movement of the arms (P < .0001), pushing up on the arms (P < .0001), elbow positioning in relation to the shoulder (P = .0039), weight bearing on hands in the mid position (P = .0002), anterior thigh positioning in relation to the floor (P = .0008), and knee extension (P = .0334).8  Likewise, infants who spent >15 minutes per day of awake time in a prone position at 2 months of age were more likely to achieve earlier 45° and 90° head up and were more likely to sit head steady.12 

BMI

One study revealed a significant association between developmental milestones, level of BMI-z, and time spent in tummy time at 2 months of age (P < .0001). More time in tummy time resulted in a higher percentage of infants achieving prone developmental milestones (P < .01). In addition, there was an association between an increase in daily tummy time past the threshold of 12 minutes per day at age 2 months and a decline in BMI-z at 4 months.

Social Communication and Cognition

The authors of one study investigated the association between tummy time and communication. They found a significant difference between prone and nonprone infants in the communication domain (P = .027) that persisted until 1 year (P =.003) but no association after this age. In 2 studies, authors investigated the effect of tummy time on cognition. In one study, authors found a significant association between the infant’s ability to move while prone at 6 months of age and cognition (problem-solving), which persisted until the infant was 2 years old. However, combining this result with that of the other study investigating cognition resulted in an indeterminate association overall (Table 5).

Fine Motor Development

In 4 studies, authors investigated the association of tummy time with fine motor development. No association was found in 10 of 15 outcomes measured.

In this systematic review, we identified the association of tummy time with a range of infant health and development outcomes. Combining the current available evidence further confirms the importance of tummy time to enhance infant development. In addition, it highlights the association of tummy time with specific aspects of motor development (ability to move while prone or supine, including rolling and crawling), the reduction in BMI-z, and the prevention of brachycephaly. This review also further reveals the need for objective tummy time measurement techniques because subjective questionnaires or parent position logs were used in all included studies.

Investigating specific benefits of tummy time can be beneficial for parents, health care professionals, and early-care educators. Attainment of specific “small skills,” such as the ability of the infant to lift their head off the ground, the ability to move their arms and legs while prone, the ability to reach while prone, and the ability to sit with their arms supporting them, are small yet tangible goals parents can strive to meet. This was shown in a previous study44  in which tummy time was achieved by the infants’ first learning to lift their heads, then lift their legs, then lift their arms. This order of achievement of tummy time was shown to be positively correlated with their ability to move when on their stomachs.31  Breaking down the achievement of “big skills,” such as rolling, sitting up unsupported, and walking, into smaller, achievable stages of motor development could be a motivating factor, especially for those struggling with meeting the guidelines for tummy time; however, this is currently unknown.

The findings in this study are similar to those in the systematic review by Carson et al,24  who found that tummy time participation of <3 times per day was significantly associated with plagiocephaly in unadjusted models25  and that at least 30 minutes of tummy time per day appeared beneficial to motor development.23  Fourteen additional studies were found in the current review because of new studies published and the reduced number of participants required in our inclusion criteria. It is also interesting to note that the incidence of positional plagiocephaly in the population measured by Mawji et al37  in 2014 (n = 440) was 46.6% at 9 weeks of age. In the study by van Vlimmeren et al25  in 2007 (n = 357), the incidence was 22.1% at 7 weeks of age. Because a low level of motor development is a risk factor for plagiocephaly,35  this rise in plagiocephaly from 2007 to 2018 may be a potential indicator of a generation of infants not achieving the motor development skills they require. Previous studies also revealed an increased incidence in head-shape abnormalities after the introduction of the Back to Sleep campaign.3  Despite this, parents are encouraged to continue to place their infants supine to sleep and to counteract these negative effects by ensuring participation in recommended levels of tummy time when their infants are awake and supervised.45 

To our knowledge, this is the first systematic review that includes a positive association of tummy time with BMI.36  This information is vital to include in the list of health benefits of tummy time for infants. Because there is currently only one study in which the association of tummy time with BMI is being investigated, further research into the effect of tummy time on unhealthy weight gain among young children is recommended. At this time, the guidelines are focused on the prevention of plagiocephaly and the enhancement of motor development. The inclusion of the benefit of a reduction in infant BMI-z will be an important finding to translate to assist parents and educators with adherence to the global physical activity guidelines. These findings may also guide the prioritization of interventions aimed at increasing tummy time practices for both healthy infants as well as infants with developmental disorders.

Current adherence to the infant physical activity guidelines is 30% in Australia.21,46  Correlates that are negatively associated with tummy time are older parents, low education level, and the amount of time spent awake in the supine position.31  It has also been shown that knowledge of tummy time, having a fearful attitude about tummy time,47  and receiving information about tummy time from a pediatrician has minimal effect on tummy time.34  Further investigation into the causes of this low adherence rate and strategies to improve adherence is required.

Limitations of this study are the small number of studies available to review. A publication bias may also be present because it is unknown if other studies were conducted but not published because of null results. In addition, most studies were observational in design and lacked the robustness of a randomized controlled trial design. High selection and performance bias were present for the majority of studies, which reduces their ability to be accurately representative of other socioeconomic and cultural groups. As such, race, ethnicity, country, socioeconomic status, and cultural effects on tummy time remain to be investigated. Limits were placed on the selection criteria to only include studies written in English and studies that included tummy time as awake prone positioning on the floor. In addition, in some studies, authors combined various interventions (supine positioning, prone positioning, prone sleeping, counseling, nutrition, etc) and investigated the combined effect of these interventions on infant health outcomes. To include these in the review would have confounded the effect tummy time alone had on infant health outcomes because it would be impossible to determine the effect tummy time alone had on the measured infant outcomes. To ensure that the true (not confounded) effect of tummy time on infant health outcomes could be examined, studies were only included if the authors conducted an exclusive tummy time intervention. As such, this may have excluded some studies written in other languages, studies in which authors investigated a combination of interventions, or studies that had tummy time on a location other than the floor, which may have revealed associations different from those in this review. In addition, studies that had infants with and without plagiocephaly grouped together were also excluded because of the potential differences in motor development that could not be distinguished.

Although authors of a number of systematic reviews have examined the effect of physical activity interventions on older children’s health outcomes,16,24  research to examine the relationships between physical activity and health among infants is limited. It is recommended that more research be conducted to examine the relationships between physical activity and health indicators in infants. This can ensure the identification of developmentally appropriate types and doses of physical activity that have a positive impact on the health and well-being of the infant.

In this study, we systematically reviewed evidence from 16 studies regarding the association of tummy time with infant health outcomes. Total development, gross motor development, and the ability to move while prone or supine (including crawling) were the health outcomes that had a significantly strong positive association. Studies, by using tummy time objective measurement techniques and assessing a broader range of health outcomes, are warranted to further inform future physical activity guidelines for infants.

Clinical implications and public health significance are as follows:

  • Results from this review (tummy time being positively associated with gross motor and total development, reduction in BMI-z, prevention of brachycephaly, and ability to move while prone or supine, including crawling and rolling) can be used to educate parents about the benefits of tummy time.

  • Further understanding of the effects of tummy time on infant health and development may assist to improve compliance with the World Health Organization tummy time recommendations of 30 minutes per day.

  • This review reveals that further work is required regarding the objective measurement of tummy time rather than reliance on parent-proxy questionnaires.

Dr Hewitt conceptualized and designed the study, conducted the screening of records, appraised the quality of evidence, extracted, analyzed, and interpreted the data, drafted the initial manuscript, and reviewed and revised the manuscript; Ms Kerr conducted the screening of the records, appraised the quality of evidence, extracted, analyzed, and interpreted the data, and critically reviewed the manuscript for important intellectual content; Drs Stanley and Okely supervised data collection and critically reviewed the manuscript for important intellectual content; and all authors approved the final manuscript as submitted.

This trial has been registered with PROSPERO (http://www.crd.york.ac.uk/prospero) (identifier CRD42017075156).

FUNDING: Supported by the Australian Government Research Training Program Scholarship (Dr Hewitt).

     
  • AIMS

    Alberta Infant Motor Scale

  •  
  • BMI-z

    BMI z score

  •  
  • SIDS

    sudden infant death syndrome

1
American Academy of Pediatrics
;
AAP Task Force on Infant Positioning and SIDS
.
Positioning and SIDS [published correction appears in Pediatrics. 1992;90(2, pt 1):264]
.
Pediatrics
.
1992
;
89
(
6, pt 1
):
1120
1126
2
Willinger
M
,
Hoffman
HJ
,
Wu
KT
, et al
.
Factors associated with the transition to nonprone sleep positions of infants in the United States: the National Infant Sleep Position Study
.
JAMA
.
1998
;
280
(
4
):
329
335
3
Davis
BE
,
Moon
RY
,
Sachs
HC
,
Ottolini
MC
.
Effects of sleep position on infant motor development
.
Pediatrics
.
1998
;
102
(
5
):
1135
1140
4
Jantz
JW
,
Blosser
CD
,
Fruechting
LA
.
A motor milestone change noted with a change in sleep position
.
Arch Pediatr Adolesc Med
.
1997
;
151
(
6
):
565
568
5
Argenta
LC
,
David
LR
,
Wilson
JA
,
Bell
WO
.
An increase in infant cranial deformity with supine sleeping position
.
J Craniofac Surg
.
1996
;
7
(
1
):
5
11
6
Chizawsky
LL
,
Scott-Findlay
S
.
Tummy time! Preventing unwanted effects of the “Back to Sleep” campaign
.
AWHONN Lifelines
.
2005
;
9
(
5
):
382
387
7
Wen
LM
,
Baur
LA
,
Simpson
JM
,
Rissel
C
,
Flood
VM
.
Effectiveness of an early intervention on infant feeding practices and “tummy time”: a randomized controlled trial
.
Arch Pediatr Adolesc Med
.
2011
;
165
(
8
):
701
707
8
Russell
DC
,
Kriel
H
,
Joubert
G
,
Goosen
Y
.
Prone positioning and motor development in the first 6 weeks of life
.
South African Journal of Occupational Therapy
.
2009
;
39
(
1
):
11
14
9
Dudek-Shriber
L
,
Zelazny
S
.
The effects of prone positioning on the quality and acquisition of developmental milestones in four-month-old infants
.
Pediatr Phys Ther
.
2007
;
19
(
1
):
48
55
10
Majnemer
A
,
Barr
RG
.
Influence of supine sleep positioning on early motor milestone acquisition
.
Dev Med Child Neurol
.
2005
;
47
(
6
):
370
376; discussion 364
11
Monson
RM
,
Deitz
J
,
Kartin
D
.
The relationship between awake positioning and motor performance among infants who slept supine
.
Pediatr Phys Ther
.
2003
;
15
(
4
):
196
203
12
Salls
JS
,
Silverman
LN
,
Gatty
CM
.
The relationship of infant sleep and play positioning to motor milestone achievement
.
Am J Occup Ther
.
2002
;
56
(
5
):
577
580
13
Indolfi
G
,
Hierro
L
,
Dezsofi
A
, et al
.
Treatment of chronic hepatitis C virus infection in children: a position paper by the Hepatology Committee of European Society of Paediatric Gastroenterology, Hepatology and Nutrition
.
J Pediatr Gastroenterol Nutr
.
2018
;
66
(
3
):
505
515
14
Okely
AD
,
Ghersi
D
,
Hesketh
KD
, et al
.
A collaborative approach to adopting/adapting guidelines - the Australian 24-hour movement guidelines for the early years (birth to 5 years): an integration of physical activity, sedentary behavior, and sleep
.
BMC Public Health
.
2017
;
17
(
suppl 5
):
869
15
Reilly
JJ
,
Hughes
A
,
Janssen
X
. Expert working group working paper: Under 5s. UK physical activity guidelines: draft review and recommendations for the Under 5s.
2018
. Available at: www.bristol.ac.uk/media-library/sites/sps/documents/cmo/under-5s-technical-report.pdf. Accessed March 14, 2019
16
Tremblay
MS
,
Chaput
JP
,
Adamo
KB
, et al
.
Canadian 24-hour movement guidelines for the early years (0-4 years): an integration of physical activity, sedentary behaviour, and sleep
.
BMC Public Health
.
2017
;
17
(
suppl 5
):
874
17
Institute of Medicine
.
Early childhood obesity prevention policies: goals, recommendations, and potential actions. 2011
.
18
American Academy of Pediatrics
.
19
World Health Organization
.
Guidelines on physical activity, sedentary behaviour and sleep for children under 5 years of age.
2019
. Available at: https://apps.who.int/iris/handle/10665/311664. Accessed March 14, 2019
20
Hewitt
L
,
Benjamin-Neelon
SE
,
Carson
V
,
Stanley
RM
,
Janssen
I
,
Okely
AD
.
Child care centre adherence to infant physical activity and screen time recommendations in Australia, Canada and the United States: an observational study
.
Infant Behav Dev
.
2018
;
50
:
88
97
21
Gross
RS
,
Mendelsohn
AL
,
Yin
HS
, et al
.
Randomized controlled trial of an early child obesity prevention intervention: impacts on infant tummy time
.
Obesity (Silver Spring)
.
2017
;
25
(
5
):
920
927
22
van Vlimmeren
LA
,
van der Graaf
Y
,
Boere-Boonekamp
MM
,
L’Hoir
MP
,
Helders
PJ
,
Engelbert
RH
.
Effect of pediatric physical therapy on deformational plagiocephaly in children with positional preference: a randomized controlled trial
.
Arch Pediatr Adolesc Med
.
2008
;
162
(
8
):
712
718
23
Kuo
YL
,
Liao
HF
,
Chen
PC
,
Hsieh
WS
,
Hwang
AW
.
The influence of wakeful prone positioning on motor development during the early life
.
J Dev Behav Pediatr
.
2008
;
29
(
5
):
367
376
24
Carson
V
,
Lee
EY
,
Hewitt
L
, et al
.
Systematic review of the relationships between physical activity and health indicators in the early years (0-4 years) [published correction appears in BMC Public Health. 2017;17(1):985]
.
BMC Public Health
.
2017
;
17
(
suppl 5
):
854
25
van Vlimmeren
LA
,
van der Graaf
Y
,
Boere-Boonekamp
MM
,
L’Hoir
MP
,
Helders
PJ
,
Engelbert
RH
.
Risk factors for deformational plagiocephaly at birth and at 7 weeks of age: a prospective cohort study
.
Pediatrics
.
2007
;
119
(
2
). Available at: www.pediatrics.org/cgi/content/full/119/2/e408
26
Berk
LE
.
Development Through the Lifespan
, 6th ed.
Boston, MA
:
Pearson Higher Education
;
2014
27
Moher
D
,
Liberati
A
,
Tetzlaff
J
,
Altman
DG
;
PRISMA Group
.
Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement
.
PLoS Med
.
2009
;
6
(
7
):
e1000097
28
Schardt
C
,
Adams
MB
,
Owens
T
,
Keitz
S
,
Fontelo
P
.
Utilization of the PICO framework to improve searching PubMed for clinical questions
.
BMC Med Inform Decis Mak
.
2007
;
7
:
16
29
Guyatt
G
,
Oxman
AD
,
Akl
EA
, et al
.
GRADE guidelines: 1. Introduction-GRADE evidence profiles and summary of findings tables
.
J Clin Epidemiol
.
2011
;
64
(
4
):
383
394
30
Guyatt
GH
,
Oxman
AD
,
Sultan
S
, et al;
GRADE Working Group
.
GRADE guidelines: 9. Rating up the quality of evidence
.
J Clin Epidemiol
.
2011
;
64
(
12
):
1311
1316
31
Hewitt
L
,
Stanley
RM
,
Okely
AD
.
Correlates of tummy time in infants aged 0-12 months old: a systematic review
.
Infant Behav Dev
.
2017
;
49
:
310
321
32
Higgins
JPT
,
Green
S
, eds
.
Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [Updated March 2011]
.
London, United Kingdom
:
The Cochrane Collaboration
;
2011
33
Guyatt
GH
,
Oxman
AD
,
Vist
G
, et al
.
GRADE guidelines: 4. Rating the quality of evidence–study limitations (risk of bias)
.
J Clin Epidemiol
.
2011
;
64
(
4
):
407
415
34
Jennings
JT
,
Sarbaugh
BG
,
Payne
NS
.
Conveying the message about optimal infant positions
.
Phys Occup Ther Pediatr
.
2005
;
25
(
3
):
3
18
35
Aarnivala
H
,
Vuollo
V
,
Harila
V
, et al
.
The course of positional cranial deformation from 3 to 12 months of age and associated risk factors: a follow-up with 3D imaging
.
Eur J Pediatr
.
2016
;
175
(
12
):
1893
1903
36
Koren
A
,
Kahn-D’angelo
L
,
Reece
SM
,
Gore
R
.
Examining childhood obesity from infancy: the relationship between tummy time, infant BMI-z, weight gain, and motor development-an exploratory study
.
J Pediatr Health Care
.
2019
;
33
(
1
):
80
91
37
Mawji
A
,
Vollman
AR
,
Fung
T
,
Hatfield
J
,
McNeil
DA
,
Sauvé
R
.
Risk factors for positional plagiocephaly and appropriate time frames for prevention messaging
.
Paediatr Child Health
.
2014
;
19
(
8
):
423
427
38
Soska
KC
,
Adolph
KE
.
Postural position constrains multimodal object exploration in infants
.
Infancy
.
2014
;
19
(
2
):
138
161
39
Carmeli
E
,
Marmur
R
,
Cohen
A
,
Tirosh
E
.
Preferred sleep position and gross motor achievement in early infancy
.
Eur J Pediatr
.
2009
;
168
(
6
):
711
715
40
Majnemer
A
,
Barr
RG
.
Association between sleep position and early motor development
.
J Pediatr
.
2006
;
149
(
5
):
623
629
41
Senju
A
,
Shimono
M
,
Tsuji
M
, et al
.
Inability of infants to push up in the prone position and subsequent development
.
Pediatr Int
.
2018
;
60
(
9
):
811
819
42
De Bock
F
,
Braun
V
,
Renz-Polster
H
.
Deformational plagiocephaly in normal infants: a systematic review of causes and hypotheses
.
Arch Dis Child
.
2017
;
102
(
6
):
535
542
43
Rogers
GF
.
Deformational plagiocephaly, brachycephaly, and scaphocephaly. Part I: terminology, diagnosis, and etiopathogenesis
.
J Craniofac Surg
.
2011
;
22
(
1
):
9
16
44
Horowitz
L
,
Sharby
N
.
Development of prone extension postures in healthy infants
.
Phys Ther
.
1988
;
68
(
1
):
32
39
45
Pin
T
,
Eldridge
B
,
Galea
MP
.
A review of the effects of sleep position, play position, and equipment use on motor development in infants
.
Dev Med Child Neurol
.
2007
;
49
(
11
):
858
867
46
Hesketh
KD
,
Downing
KL
,
Campbell
K
,
Crawford
D
,
Salmon
J
,
Hnatiuk
JA
.
Proportion of infants meeting the Australian 24-hour Movement Guidelines for the early years: data from the Melbourne InFANT Program
.
BMC Public Health
.
2017
;
17
(
suppl 5
):
856
47
Ricard
A
,
Metz
AE
.
Caregivers’ knowledge, attitudes, and implementation of awake infant prone positioning
.
J Occup Ther Sch Early Interv
.
2014
;
7
(
1
):
16
28

Competing Interests

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.

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