Objective measurement of tummy time in infants (0-6 months): A validation study

Predictors of Length of Physical Therapy Care for Infants With Congenital Torticollis

PURPOSE

This study explored whether the type of torticollis, amount of tummy time or container time, participant age at examination, and Alberta Infant Motor Scales score influence the length of physical therapy care for infants with torticollis.

METHODS

Data for 149 participants were extracted from medical records for infants with torticollis who received care between November 2018 and November 2021.

RESULTS

Statistically significant correlations were found between length of care (LOC) and torticollis type, age at examination, active range of motion rotation deficit, and passive range of motion rotation deficit. A multiple regression model predicted LOC from age at examination in days, as well as passive and active rotation deficits.

CONCLUSION

Higher passive and active rotation deficits lead to longer LOC. However, longer lengths of care were associated with younger ages at examination, different from earlier studies.

Pediatric Monitoring Technologies and Congenital Heart Disease: A Systematic Review

Outpatient monitoring of infants with congenital heart disease has been shown to significantly reduce rates of mortality in the single ventricle population. Despite the accelerating development of miniaturized biosensors and electronics, and a growing market demand for at-home monitoring devices, the application of these technologies to infants and children is significantly delayed compared with the development of devices for adults. This article aims to review the current landscape of available monitoring technologies and devices for pediatric patients to describe the gap between technologies and clinical needs with the goal of progressing development of clinically and scientifically validated pediatric monitoring devices.

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.

Accelerometer Thresholds for Estimating Physical Activity Intensity Levels in Infants: A Preliminary Study

Lack of physical activity (PA) at a young age can result in health issues. Thus, monitoring PA is important. Wearable accelerometers are the preferred tool to monitor PA in children. Validated thresholds are used to classify activity intensity levels, e.g., sedentary, light, and moderate-to-vigorous, in ambulatory children. No previous work has developed accelerometer thresholds for infancy (pre-ambulatory children). Therefore, this work aims to develop accelerometer thresholds for PA intensity levels in pre-ambulatory infants. Infants (n = 10) were placed in a supine position and allowed free movement. Their movements were synchronously captured using video cameras and accelerometers worn on each ankle. The video data were labeled by activity intensity level (sedentary, light, and moderate-to-vigorous) in two-second epochs using observational rating (gold standard). Accelerometer thresholds were developed for acceleration and jerk using two optimization approaches. Four sets of thresholds were developed for dual (two ankles) and for single-worn (one ankle) accelerometers. Of these, for a typical use case, we recommend using acceleration-based thresholds of 1.00 m/s to distinguish sedentary and light activity and 2.60 m/s to distinguish light and moderate-to-vigorous activity. Acceleration and jerk are both suitable for measuring PA.

Tummy Time Tracking: Examining Agreement Between Parent Recall and Direct Observation in Infants

IMPORTANCE

Parent recall is the primary method for measuring positioning practices such as tummy time in infants. Concerns regarding the accuracy of parent recall have been raised in the literature. To date, no study has examined the agreement of tummy time recall measures with gold-standard methods.

OBJECTIVE

To assess the agreement between parental recall versus direct observation of tummy time in infants, and to explore the impact of prematurity on this relationship.

DESIGN

Cross-sectional observational study, spanning 1 yr.

SETTING

Participants' homes Participants: Thirty-two infant-parent dyads (19 full-term, 13 preterm), with infants ages 3 to 6 mo and caregivers ages older than 18 yr.

OUTCOME AND MEASURES

Home-recorded videos of infant play across 3 days were used as a proxy for direct observation of tummy time and compared with a 12-item parent recall survey.

RESULTS

Parent recall had a significant moderate correlation (ρ = .54, p = .002) with direct observation in full-term infants but was not correlated (p = .23) with direct observation in preterm infants. On average, parents of preterm infants overestimated tummy time by 2.5 times per day compared with direct observation.

CONCLUSIONS AND RELEVANCE

For full-term infants, parent recall measures of tummy time exhibit an acceptable level of agreement with direct observation and can be reliably used over shorter periods. Parents of preterm infants may display a bias in recalling tummy time, leading to overestimations. To accurately assess tummy time in this population, a combination of subjective and objective measures should be explored. Plain-Language Summary: Tummy time is an essential movement experience for infants, especially for preterm infants, who are at a higher risk for motor delays. The most common way to track tummy time is through parent reports, or recall, versus a practitioner directly observing tummy time in the home. Despite the widespread use of parent recall to track tummy time, no study has examined the accuracy of parent recall versus direct observation in the home. Accurately assessing tummy time is crucial for improving and supporting health outcomes for infants. This study found that prematurity may affect the accuracy of parent recall for assessing tummy time in young infants. The authors discuss the implications of this finding and provide suggestions to guide the selection of appropriate methods to measure tummy time in clinical practice and research studies.

Objective Measurement of Posture and Movement in Young Children Using Wearable Sensors and Customised Mathematical Approaches: A Systematic Review

Given the importance of young children's postures and movements to health and development, robust objective measures are required to provide high-quality evidence. This study aimed to systematically review the available evidence for objective measurement of young (0-5 years) children's posture and movement using machine learning and other algorithm methods on accelerometer data. From 1663 papers, a total of 20 papers reporting on 18 studies met the inclusion criteria. Papers were quality-assessed and data extracted and synthesised on sample, postures and movements identified, sensors used, model development, and accuracy. A common limitation of studies was a poor description of their sample data, yet over half scored adequate/good on their overall study design quality assessment. There was great diversity in all aspects examined, with evidence of increasing sophistication in approaches used over time. Model accuracy varied greatly, but for a range of postures and movements, models developed on a reasonable-sized (n > 25) sample were able to achieve an accuracy of >80%. Issues related to model development are discussed and implications for future research outlined. The current evidence suggests the rapidly developing field of machine learning has clear potential to enable the collection of high-quality evidence on the postures and movements of young children.

The use of wireless sensors in the neonatal intensive care unit: a study protocol

Background

Continuous monitoring of vital signs and other biological signals in the Neonatal Intensive Care Unit (NICU) requires sensors connected to the bedside monitors by wires and cables. This monitoring system presents challenges such as risks for skin damage or infection, possibility of tangling around the patient body, or damage of the wires, which may complicate routine care. Furthermore, the presence of cables and wires can act as a barrier for parent-infant interactions and skin to skin contact. This study will investigate the use of a new wireless sensor for routine vital monitoring in the NICU.

Methods

Forty-eight neonates will be recruited from the Montreal Children's Hospital NICU. The primary outcome is to evaluate the feasibility, safety, and accuracy of a wireless monitoring technology called ANNE® One (Sibel Health, Niles, MI, USA). The study will be conducted in 2 phases where physiological signals will be acquired from the standard monitoring system and the new wireless monitoring system simultaneously. In phase 1, participants will be monitored for 8 h, on four consecutive days, and the following signals will be obtained: heart rate, respiratory rate, oxygen saturation and skin temperature. In phase 2, the same signals will be recorded, but for a period of 96 consecutive hours. Safety and feasibility of the wireless devices will be assessed. Analyses of device accuracy and performance will be accomplished offline by the biomedical engineering team.

Conclusion

This study will evaluate feasibility, safety, and accuracy of a new wireless monitoring technology in neonates treated in the NICU.

Wireless monitoring devices in hospitalized children: a scoping review

The purpose of this study is to provide a structured overview of existing wireless monitoring technologies for hospitalized children. A systematic search of the literature published after 2010 was conducted in Medline, Embase, Scielo, Cochrane, and Web of Science. Two investigators independently reviewed articles to determine eligibility for inclusion. Information on study type, hospital setting, number of participants, use of a reference sensor, type and number of vital signs monitored, duration of monitoring, type of wireless information transfer, and outcomes of the wireless devices was extracted. A descriptive analysis was applied. Of the 1130 studies identified from our search, 42 met eligibility for subsequent analysis. Most included studies were observational studies with sample sizes of 50 or less published between 2019 and 2022. Common problems pertaining to study methodology and outcomes observed were short duration of monitoring, single focus on validity, and lack information on wireless transfer and data management.  Conclusion: Research on the use of wireless monitoring for children in hospitals has been increasing in recent years but often limited by methodological problems. More rigorous studies are necessary to establish the safety and accuracy of novel wireless monitoring devices in hospitalized children. What is Known: • Continuous monitoring of vital signs using wired sensors is the standard of care for hospitalized pediatric patients. However, the use of wires may pose significant challenges to optimal care. What is New: • Interest in wireless monitoring for hospitalized pediatric patients has been rapidly growing in recent years. • However, most devices are in early stages of clinical testing and are limited by inconsistent clinical and technological reporting.

Characteristics of tummy time and dose-response relationships with development in infants

This study aimed to examine change in tummy time patterns and preferences in the first 6 months of life, as well as dose-response relationships between tummy time duration and development at 2, 4, and 6 months. Participants were parents of infants from the Early Movers project in Edmonton, Canada (baseline: n = 411). At 2, 4, and 6 months, infant tummy time duration and preference (i.e., 1 = really likes to 5 = really dislikes) and development (i.e., Ages & Stages Questionnaire (ASQ-3) communication, fine motor, gross motor, problem-solving, personal-social) were measured by a parental questionnaire. In a subsample (n = 127), tummy time patterns (i.e., bout frequency, mean and median bout length) were measured using a 3-day time-use diary. Tummy time bout frequency, bout length, and preference significantly increased over time. Linear dose-response relationships between tummy time duration and development outcomes were observed at 4 (gross motor) and 6 months (all development outcomes). Moreover, at 2 months, 30-44 min/day of tummy time was associated with a higher total development score (vs. < 15 min/day; B = 11.14; 95%CI: 1.60, 20.68). At 6 months, 61-120 min/day (vs. < 30 min/day; B = 27.12; 95%CI: 11.93, 42.32) and > 120 min/day (vs. < 30 min/day; B = 33.80; 95%CI: 18.90, 48.70) of tummy time were associated with higher total development scores. Differences in threshold doses between some developmental outcomes were observed. Conclusion: In the first 6 months of life, increases were observed in tummy time preference as well as tummy time bout frequent and length. This finding may explain why the optimal amount of tummy time needed for more advanced development appeared to increase with age. What is Known: • Tummy time is a type of physical activity in infancy. International and national guidelines recommend at least 30 minutes of tummy time per day for infants who are not yet mobile. What is New: • In the first six months of life, preference for tummy time as well as tummy time bout frequency and length increased. • Tummy time duration had dose-response associations with several development outcomes, and the optimal amount of tummy time needed for more advanced development appeared to increase with age.

Systematic review of accelerometer-based methods for 24-h physical behavior assessment in young children (0-5 years old)

BACKGROUND

Accurate accelerometer-based methods are required for assessment of 24-h physical behavior in young children. We aimed to summarize evidence on measurement properties of accelerometer-based methods for assessing 24-h physical behavior in young children.

METHODS

We searched PubMed (MEDLINE) up to June 2021 for studies evaluating reliability or validity of accelerometer-based methods for assessing physical activity (PA), sedentary behavior (SB), or sleep in 0-5-year-olds. Studies using a subjective comparison measure or an accelerometer-based device that did not directly output time series data were excluded. We developed a Checklist for Assessing the Methodological Quality of studies using Accelerometer-based Methods (CAMQAM) inspired by COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN).

RESULTS

Sixty-two studies were included, examining conventional cut-point-based methods or multi-parameter methods. For infants (0-12 months), several multi-parameter methods proved valid for classifying SB and PA. From three months of age, methods were valid for identifying sleep. In toddlers (1-3 years), cut-points appeared valid for distinguishing SB and light PA (LPA) from moderate-to-vigorous PA (MVPA). One multi-parameter method distinguished toddler specific SB. For sleep, no studies were found in toddlers. In preschoolers (3-5 years), valid hip and wrist cut-points for assessing SB, LPA, MVPA, and wrist cut-points for sleep were identified. Several multi-parameter methods proved valid for identifying SB, LPA, and MVPA, and sleep. Despite promising results of multi-parameter methods, few models were open-source. While most studies used a single device or axis to measure physical behavior, more promising results were found when combining data derived from different sensor placements or multiple axes.

CONCLUSIONS

Up to age three, valid cut-points to assess 24-h physical behavior were lacking, while multi-parameter methods proved valid for distinguishing some waking behaviors. For preschoolers, valid cut-points and algorithms were identified for all physical behaviors. Overall, we recommend more high-quality studies evaluating 24-h accelerometer data from multiple sensor placements and axes for physical behavior assessment. Standardized protocols focusing on including well-defined physical behaviors in different settings representative for children's developmental stage are required. Using our CAMQAM checklist may further improve methodological study quality.

PROSPERO REGISTRATION NUMBER

CRD42020184751.

Effect of a multicomponent intervention in postnatal mothers' groups on meeting the Australian Physical Activity Guidelines for infants: protocol for a randomised controlled trial

INTRODUCTION

Given the importance of tummy time and the low levels of tummy time reported globally, there is a need for high-quality intervention strategies to promote tummy time. This study describes the protocol of a randomised controlled trial that aims to determine the effectiveness of a multicomponent intervention delivered in postnatal mothers' groups in increasing infant tummy time.

METHODS AND ANALYSIS

A randomised controlled trial will be conducted. Eligible participants will be mothers and their infants attending postnatal mothers' groups (New South Wales, Australia). Participants will be randomised to participate in either (1) infant tummy time intervention group (practice, education, WhatsApp) plus usual care; or (2) usual care group. Randomisation process and outcome assessors will be blinded. The intervention will comprise an online education and practice session (60 min) and 4 weeks of WhatsApp messaging (standardised, three times per week). Usual care will be attendance at a mothers group once per week for 3 weeks for information and support for ad hoc mother craft activities (standard practice provided by early childhood nurses for this local health district). The primary outcome will be the amount of infant tummy time using the GENEActiv accelerometer and a questionnaire (post intervention). The accelerometer will be worn on the right hip secured by an elastic belt around the waist. Wear and non-wear time will be classified using temperature and z-axis cut points as per previous research. This protocol paper presents the scientific background and proposed methods of the randomised controlled trial. Findings will inform the design of practically based strategies to inform clinicians, educators and parents about infant physical activity.

ETHICS AND DISSEMINATION

The University of Wollongong and Illawarra Shoalhaven Local Health District Health and Medical Human Research Ethics Committee approved the study (2020/ETH02970). Dissemination plan is publication, staff training and conference presentations.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ACTRN12621000575831; Pre-results.

Longitudinal associations between infant movement behaviours and development

BACKGROUND

This study aimed to address methodological limitations of the evidence that informed national and international movement behaviour guidelines for the early years. Specifically, the primary objective was to examine the longitudinal associations of infant physical activity (i.e., tummy time) and sedentary behaviour (i.e., back time, screen time, reading time, restrained time) with gross motor development. Secondary and tertiary objectives were to examine longitudinal associations of: (1) infant physical activity and sedentary behaviour with communication, fine motor, personal-social, and problem solving development, and (2) sleep time with primary and secondary outcomes.

METHODS

Participants were 411 parents and their infants from the Early Movers project in Edmonton, Canada. Physical activity, sedentary behaviour, and sleep were measured with a parental questionnaire and the Ages & Stages Questionnaire (ASQ-3) developmental screening tool was administered at 2, 4, and 6 months. Parents reported the dates six major gross motor milestones (i.e., independent sitting, crawling, assisted standing, assisted walking, independent standing, independent walking) were acquired in the first 18 months of life according to World Health Organization criteria. In a subsample (n = 125), gross motor development was assessed using the Alberta Infant Motor Scale (AIMS) at 6 months.

RESULTS

Higher tummy time across time points was significantly associated with higher ASQ-3 gross motor and personal-social development scores over time, higher total AIMS scores at 6 months, and earlier acquisition of all gross motor milestones. Higher reading time across time points was significantly associated with higher ASQ-3 fine motor, gross motor, personal-social, and total development scores over time. In contrast, higher back time across time points was significantly associated with lower total AIMS scores at 6 months and the later acquisition of assisted standing, assisted walking, and independent walking. Similarly, higher restrained time across time points was significantly associated with a later acquisition of supported walking.

CONCLUSIONS

Tummy time was consistently longitudinally associated with more advanced gross motor development and reading with more advanced total development. Whereas, some detrimental associations were observed for back and restrained time. Findings support the promotion of tummy time and certain sedentary behaviours (i.e., reading) in young infants to enhance overall development.

Miniaturized wireless, skin-integrated sensor networks for quantifying full-body movement behaviors and vital signs in infants

Early detection of infant neuromotor pathologies is critical for timely therapeutic interventions that rely on early-life neuroplasticity. Traditional assessments rely on subjective expert evaluations or specialized medical facilities, making them challenging to scale in remote and/or resource-constrained settings. The results presented here aim to democratize these evaluations using wireless networks of miniaturized, skin-integrated sensors that digitize movement behaviors and vital signs of infants in a cost-effective manner. The resulting data yield full-body motion reconstructions in the form of deidentified infant avatars, along with a range of important cardiopulmonary information. This technology approach enables rapid, routine evaluations of infants at any age via an engineering platform that has potential for use in nearly any setting across developed and developing countries alike.

Early identification of atypical infant movement behaviors consistent with underlying neuromotor pathologies can expedite timely enrollment in therapeutic interventions that exploit inherent neuroplasticity to promote recovery. Traditional neuromotor assessments rely on qualitative evaluations performed by specially trained personnel, mostly available in tertiary medical centers or specialized facilities. Such approaches are high in cost, require geographic proximity to advanced healthcare resources, and yield mostly qualitative insight. This paper introduces a simple, low-cost alternative in the form of a technology customized for quantitatively capturing continuous, full-body kinematics of infants during free living conditions at home or in clinical settings while simultaneously recording essential vital signs data. The system consists of a wireless network of small, flexible inertial sensors placed at strategic locations across the body and operated in a wide-bandwidth and time-synchronized fashion. The data serve as the basis for reconstructing three-dimensional motions in avatar form without the need for video recordings and associated privacy concerns, for remote visual assessments by experts. These quantitative measurements can also be presented in graphical format and analyzed with machine-learning techniques, with potential to automate and systematize traditional motor assessments. Clinical implementations with infants at low and at elevated risks for atypical neuromotor development illustrates application of this system in quantitative and semiquantitative assessments of patterns of gross motor skills, along with body temperature, heart rate, and respiratory rate, from long-term and follow-up measurements over a 3-mo period following birth. The engineering aspects are compatible for scaled deployment, with the potential to improve health outcomes for children worldwide via early, pragmatic detection methods.

A Contactless Method for Measuring Full-Day, Naturalistic Motor Behavior Using Wearable Inertial Sensors

How can researchers best measure infants' motor experiences in the home? Body position-whether infants are held, supine, prone, sitting, or upright-is an important developmental experience. However, the standard way of measuring infant body position, video recording by an experimenter in the home, can only capture short instances, may bias measurements, and conflicts with physical distancing guidelines resulting from the COVID-19 pandemic. Here, we introduce and validate an alternative method that uses machine learning algorithms to classify infants' body position from a set of wearable inertial sensors. A laboratory study of 15 infants demonstrated that the method was sufficiently accurate to measure individual differences in the time that infants spent in each body position. Two case studies showed the feasibility of applying this method to testing infants in the home using a contactless equipment drop-off procedure.

Maternal Self-Confidence and Breastfeeding after Participating in a Program about Infant Prone Positioning

PURPOSE

Maternal self-confidence facilitates infant growth and new mother role development. Infant ability to breastfeed and maternal breastfeeding self-confidence are imperative to helping mothers meet their breastfeeding goals. Consistent opportunity for infant movement in the prone position has been shown to improve breastfeeding ability; however, families report a lack of knowledge of how to safely support this activity. Perceptions of maternal self-confidence, infant development, and breastfeeding success upon completion of an infant prone positioning program with focus on posture, movement, and connection were studied.

STUDY DESIGN AND METHODS

Qualitative interviews were conducted among breastfeeding mothers in three states to explore maternal perceptions of learning about infant prone positioning.

RESULTS

Thirty-five mothers who completed an infant prone positioning program shared their perceptions of infant interaction, prone play and positioning, and breastfeeding self-confidence. Four primary themes were identified from the analysis: maternal knowledge and self-confidence; strategies and practices learned; breastfeeding benefits of infant prone positioning; and motivation for program participation.

CLINICAL IMPLICATIONS

Our findings support consideration of teaching new mothers about prone positioning to enhance self-confidence in mothering, breastfeeding skills, infant development, and maternal-infant dyad bonding.

Validity of GENEActiv Accelerometer Wear and Nonwear Time for Use in Infants

BACKGROUND

Tummy time is recommended by the World Health Organization as part of its global movement guidelines for infant physical activity. To enable objective measurement of tummy time, accelerometer wear and nonwear time requires validation. The purpose of this study was to validate GENEActiv wear and nonwear time for use in infants.

METHODS

The analysis was conducted on accelerometer data from 32 healthy infants (4-25 wk) wearing a GENEActiv (right hip) while completing a positioning protocol (3 min each position). Direct observation (video) was compared with the accelerometer data. The accelerometer data were analyzed by receiver operating characteristic curves to identify optimal cut points for second-by-second wear and nonwear time. Cut points (accelerometer data) were tested against direct observation to determine performance. Statistical analysis was conducted using leave-one-out validation and Bland-Altman plots.

RESULTS

Mean temperature (0.941) and z-axis (0.889) had the greatest area under the receiver operating characteristic curve. Cut points were 25.6°C (temperature) and -0.812g (z-axis) and had high sensitivity (0.84, 95% confidence interval, 0.838-0.842) and specificity (0.948, 95% confidence interval, 0.944-0.948).

CONCLUSIONS

Analyzing GENEActiv data using temperature (>25.6°C) and z-axis (greater than -0.812g) cut points can be used to determine wear time among infants for the purpose of measuring tummy time.

Weekly group tummy time classes are feasible and acceptable to mothers with infants: a pilot cluster randomized controlled trial

BACKGROUND

The World Health Organization recommends 30 min of tummy time daily for improved motor development and reduced likelihood of plagiocephaly. As only 30% of infants meet this recommendation, parents require strategies and support to increase this proportion.

METHODS

The aim of this study was to determine the feasibility, acceptability, and potential efficacy of a group intervention to promote tummy time. The design is a cluster randomized controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis. Five groups of healthy infants (N = 35, baseline mean (SD) age 5.9 (2.8) weeks) and their mothers attending local mother's groups (Australia) were randomly allocated to the intervention or control group. The intervention group received group tummy time classes in addition to usual care. The control group received usual care with their child and family health nurse. Primary outcomes were intervention feasibility and acceptability. Secondary outcomes were tummy time duration (accelerometry), adherence to physical activity guidelines, head shape, and motor development. Measures were taken at baseline, post-intervention, and when infants were 6 months of age. Analyses were by linear mixed models and Cohen's d statistic.

RESULTS

Recruitment, retention, and collection of objective data met feasibility targets. Acceptability was also met with intervention mothers reporting the information, goal planning, and handouts significantly more useful and relevant than control group mothers (p < 0.01). Moderate effect sizes were also found at post-intervention for tummy time duration, adherence to physical activity guidelines and infant ability in prone and supine favoring the intervention group (intervention infants had a mean of 30 min and 30% adherence to guidelines (95% CI 0 to 60.6 min) compared to the control infants who had a mean of 16.6 min and 13% adherence to the guidelines (95% CI 0 to 42.1 min, Cohen's d = 0.5). Limitations were the small sample size, 4-week intervention, limited accelerometer use, and a homogenous sample of participants.

CONCLUSION

Group tummy time classes delivered in a mother's group setting were shown to be feasible and acceptable. A larger randomized controlled trial is warranted.

TRIAL REGISTRATION

ANZCTR, ACTRN12617001298303p. Registered 11 September 2017.

Infants' and toddlers' physical activity and sedentary time as measured by accelerometry: a systematic review and meta-analysis

BACKGROUND

Early experiences in physical activity (PA) are important to shape healthy movement behaviours long-term; as such, it is critical that PA is promoted from infancy, and that detrimental behaviours (e.g., prolonged sedentary time [ST]) are minimized. The purpose of this systematic review and meta-analysis was to examine infants' and toddlers' movement behaviours across daytime hours.

METHODS

Seven online databases were searched for terms related to infants (< 12 months), toddlers (12-35.9 months), PA, ST, and accelerometry. Two independent reviewers examined 4873 articles for peer-reviewed original research, published in English, that assessed infants' (counts/min) and/or toddlers' PA or ST (min/day) using accelerometry across daytime hours. Infants' mean PA level (counts/min) was averaged across studies, and ranges were produced. Estimates of toddlers' movement behaviours were aggregated meta-analytically to produce average daily rates, and accelerometer placement, cut-point validity, device type, and epoch length were tested as a moderating variables.

RESULTS

Twenty-four studies from 16 countries (published 2011-2019), representing 3699 participants, were included in the systematic review. Five studies reported on infants' PA, which ranged from 78.2 to 2580.5 cpm. Across 20 studies, toddlers' total PA, light PA, moderate-to vigorous-intensity PA, and ST ranged from 72.9 to 636.5, 48.5 to 582.4, 6.5 to 89.9, and 172.7 to 545.0 min/day, respectively. After taking into account accelerometer placement, cut-point validity, device type, and epoch length, we found that toddlers engaged in 246.19 min/day (SE = 28.50; 95% CI: 190.34, 302.04) of total PA, 194.10 min/day (SE = 28.76; 95% CI: 137.73, 250.47) of light PA, and 60.16 min/day (SE = 5.88; 95% CI: 48.64, 71.69) of moderate-to vigorous-intensity PA. Toddlers engaged in 337.04 min/day (SE = 32.67; 95% CI: 273.01, 401.07) of ST.

CONCLUSIONS

With limited studies conducted in infants (n = 5), PA estimates are inconclusive and largely heterogeneous. Overall, toddlers tend to exceed the total PA recommendation of 180 min/day; however, very little of this time is spent at higher movement intensities. Even with high PA rates, toddlers still engage in substantial ST. More consistent and valid measurement protocols are needed to improve comparability across studies.