The Utility of Calibrating Wearable Sensors before Quantifying Infant Leg Movements.

While interest in using wearable sensors to measure infant leg movement is increasing, attention should be paid to the characteristics of the sensors. Specifically, offset error in the measurement of gravitational acceleration (g) is common among commercially available sensors. In this brief report, we demonstrate how we measured the offset and other errors in three different off-the-shelf wearable sensors available to professionals and how they affected a threshold-based movement detection algorithm for the quantification of infant leg movement. We describe how to calibrate and correct for these offsets and how conducting this improves the reproducibility of results across sensors.

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.

Agreement Between the Gross Motor Ability Estimator-2 and the Gross Motor Ability Estimator-3 in Young Children With Cerebral Palsy.

PURPOSE: The purpose of this study was to determine the agreement between Gross Motor Ability Estimator-2 (GMAE-2) and Gross Motor Ability Estimator-3 (GMAE-3) calculations of Gross Motor Function Measure-66 (GMFM-66) scores in infants and young children with cerebral palsy. METHODS: Data from 53 children 5 to 53 months of age were analyzed. Agreement between GMFM-66 scores using the GMAE-2 and the GMAE-3 was calculated using Bland-Altman plots and interclass correlation coefficients (ICCs). Eleven participants who had at least 1 GMFM-66 score of less than 25 using either method were identified for further analysis. RESULTS: The average difference between GMFM-66 scores was 0.27 for all participants and 0.63 for the subset of lower-scoring participants. Good agreement was found for GMFM-66 scores for all participants (ICC = 0.998) and for subset of lower-scoring participants (ICC = 0.879). CONCLUSIONS: High levels of agreement exist between the GMAE-2 and the GMAE-3, which suggests that scores are comparable using either algorithm.

Maternal perceived stress and infant behavior during the COVID-19 pandemic.

BACKGROUND: Maternal stress has negative consequences on infant behavioral development, and COVID-19 presented uniquely stressful situations to mothers of infants born during the pandemic. We hypothesized that mothers with higher levels of perceived stress during the pandemic would report higher levels of infant regulatory problems including crying and interrupted sleep patterns. METHODS: As part 6 sites of a longitudinal study, mothers of infants born during the pandemic completed the Perceived Stress Scale, the Brief Infant Sleep Questionnaire, and an Infant Crying survey at 6 (n = 433) and 12 (n = 344) months of infant age. RESULTS: Maternal perceived stress, which remained consistent at 6 and 12 months of infant age, was significantly positively correlated with time taken to settle infants. Although maternal perceived stress was not correlated with uninterrupted sleep length, time taken to put the infant to sleep was correlated. Perceived stress was also correlated with the amount of infant crying and fussiness reported at 6 months. CONCLUSIONS: Mothers who reported higher levels of perceived stress during the pandemic reported higher levels of regulatory problems, specifically at 6 months. Examining how varying levels of maternal stress and infant behaviors relate to overall infant developmental status over time is an important next step. IMPACT: Women giving birth during the COVID-19 pandemic who reported higher levels of stress on the Perceived Stress Scale also reported higher levels of infant fussiness and crying at 6 months old, and more disruptive sleep patterns in their infants at 6 months and 12 months old. Sleeping problems and excessive crying in infancy are two regulatory problems that are known risk factors for emotional and behavioral issues in later childhood. This paper is one of the first studies highlighting the associations between maternal stress and infant behaviors during the COVID-19 pandemic.

Barcoding, linear and nonlinear analysis of full-day leg movements in infants with typical development and infants at risk of developmental disabilities: Cross-sectional study.

Traditional methods do not capture the multidimensional domains and dynamic nature of infant behavioral patterns. We aim to compare full-day, in-home leg movement data between infants with typical development (TD) and infants at risk of developmental disabilities (AR) using barcoding and nonlinear analysis. Eleven infants with TD (2-10 months) and nine infants AR (adjusted age: 2-14 months) wore a sensor on each ankle for 7 days. We calculated the standard deviation for linear variability and sample entropy (SampEn) of leg acceleration and angular velocity for nonlinear variability. Movements were also categorized into 16 barcoding states, and we calculated the SampEn and proportions of the barcoding. All variables were compared between the two groups using independent-samples t-test or Mann-Whitney U test. The AR group had larger linear variability compared to the TD group. SampEn was lower in the AR group compared to TD group for both acceleration and angular velocity. Two barcoding states' proportions were significantly different between the two groups. The results showed that nonlinear analysis and barcoding could be used to identify the difference of dynamic multidimensional movement patterns between infants AR and infants with TD. This information may help early diagnosis of developmental disabilities in the future.

Daily Quantity and Kinematic Characteristics of Leg Movement in a Child With SMA (2 Copies SMN2).

PURPOSE: This case report describes daily leg movement quantity and kinematic characteristics of a child with spinal muscular atrophy (SMA) with 2 copies of SMN2, who was symptomatic at the time of treatment with disease-modifying therapies. KEY POINTS: Compared with infants with typical development, this child had differing values for leg movement quantity, duration, average acceleration, and peak acceleration measured across full days in the natural environment by wearable sensors. In addition, movement quantity and clinician-rated outcomes increased with age. CONCLUSIONS: Wearable sensors recorded movement quantity and kinematic characteristics in a treated infant with SMA (2 copies SMN2). These movement parameters were consistently different compared anecdotally with published data from infants with typical development, demonstrating their potential to add unique and complementary information to the assessment of motor function in SMA. RECOMMENDATIONS: Larger longitudinal studies are needed to determine the utility of wearable sensors as an assessment tool and an early predictor of motor outcomes in children with SMA.

Qualitative and Quantitative Measures of Joint Attention Development in the First Year of Life: A Scoping Review.

Joint attention (JA) is the purposeful coordination of an individual's focus of attention with that of another and begins to develop within the first year of life. Delayed, or atypically developing, JA is an early behavioral sign of many developmental disabilities and so assessing JA in infancy can improve our understanding of trajectories of typical and atypical development. This scoping review identified the most common methods for assessing JA in the first year of life. Methods of JA were divided into qualitative and quantitative categories. Out of an identified 13,898 articles, 106 were selected after a robust search of four databases. Frequent methods used were eye tracking, electroencephalography (EEG), behavioral coding and the Early Social Communication Scale (ECSC). These methods were used to assess JA in typically and atypically developing infants in the first year of life. This study provides a comprehensive review of the past and current state of measurement of JA in the literature, the strengths and limitations of the measures used, and the next steps to consider for researchers interested in investigating JA to strengthen this field going forwards.

Geotemporal analysis of perinatal care changes and maternal mental health: an example from the COVID-19 pandemic.

Our primary objective was to document COVID-19 induced changes to perinatal care across the USA and examine the implication of these changes for maternal mental health. We performed an observational cross-sectional study with convenience sampling using direct patient reports from 1918 postpartum and 3868 pregnant individuals collected between April 2020 and December 2020 from 10 states across the USA. We leverage a subgroup of these participants who gave birth prior to March 2020 to estimate the pre-pandemic prevalence of specific birthing practices as a comparison. Our primary analyses describe the prevalence and timing of perinatal care changes, compare perinatal care changes depending on when and where individuals gave birth, and assess the linkage between perinatal care alterations and maternal anxiety and depressive symptoms. Seventy-eight percent of pregnant participants and 63% of postpartum participants reported at least one change to their perinatal care between March and August 2020. However, the prevalence and nature of specific perinatal care changes occurred unevenly over time and across geographic locations. The separation of infants and mothers immediately after birth and the cancelation of prenatal visits were associated with worsened depression and anxiety symptoms in mothers after controlling for sociodemographic factors, mental health history, number of pregnancy complications, and general stress about the COVID-19 pandemic. Our analyses reveal widespread changes to perinatal care across the US that fluctuated depending on where and when individuals gave birth. Disruptions to perinatal care may also exacerbate mental health concerns, so focused treatments that can mitigate the negative psychiatric sequelae of interrupted care are warranted.

Infant Reaching in the First Year of Life: A Scoping Review of Typical Development and Examples of Atypical Development.

AIMS: Our objective was to identify the most common variables used for infant reaching assessment, describe values of these variables across the first year of life, and identify methodological considerations and knowledge gaps for future research. METHODS: Studies were included if they met the following criteria: (1) assessed infant reaching in any position, (2) included a sample of infants with typical development: healthy, full-term, with no known impairments, (3) infants were under one year old at the first data collection, and (4) counted successful reaches resulting in object contact. RESULTS: We identified 6 commonly assessed kinematic reaching variables: frequency, duration, movement units, peak velocity, average velocity, and straightness index. Methodological inconsistencies limit our ability to interpret values of these variables across studies. CONCLUSIONS: Eliminating inconsistencies in study design and data analysis methods is the next step to defining a normative reference standard for reaching development. Establishing a normative reference standard for reaching in the first year of life will be important for assessment of typical and atypical reaching development.

Leg Movement Rate before and after a Caregiver-Provided Intervention for Infants at Risk of Developmental Disability: A Pilot Study.

AIM: Our purpose was to assess daily leg movement rate before and after a caregiver-provided in-home intervention for infants at risk for developmental disability. We also assessed adherence and quality of caregiver-child interaction. METHODS: Twelve infants, at risk for developmental disabilities, and their caregivers participated in an intervention focused on increasing leg movements. Intervention started between 3- and 6-months corrected age and ended once the infant was able to sit independently or at 9 months corrected age, whichever occurred first. Infants were assessed monthly. RESULTS: Infants at risk for developmental disabilities who were moving less than 1200 leg movements per hour awake at the start of the intervention increased their daily leg movement rate following the intervention (Median [range]: pre-1047 [506-1056], post- 1104 [655-1359], p = 0.040). Additionally, the caregivers had a high adherence (Median: 89%, Range: 11.43%-329.17%) and good quality of caregiver-child interaction (Median NCAST total: 46, Range: 34-59); and maintained similar amounts of adherence (p = 0.575) and quality of caregiver-child interaction (p = 0.432) throughout the intervention. CONCLUSION: This study provides preliminary evidence that leg movement rate has the potential to be used as an outcome measure to assess an infant's progress and motor practice during an intervention.

The Association Between Weight Gain, Sex, and Immune Activation Following the Initiation of Antiretroviral Therapy.

BACKGROUND: Immune activation persists despite suppressive antiretroviral therapy (ART) and may be affected by sex or body composition. We explored these relationships in a subset of participants who initiated ART in two large randomized trials. METHODS: Purposeful sampling selected participants who achieved virologic suppression on ART and either maintained weight within ± 0.5 kg/m2 or gained 2.6-6.4 kg/m2 from baseline to 96 weeks. We measured 7 markers of inflammation and immune activation at weeks 0 and 96. Multivariable linear regression explored associations of weight gain, sex, and pre-ART BMI with pre-ART and changes in biomarker concentrations. RESULTS: 340 participants were selected; median pre-ART age 42 years, CD4+ cell count 273 cells/mm3, HIV-1 RNA 4.7 log10 copies/mL; 49% were women, 33% white, 42% black, and 24% Hispanic. Among participants with a normal pre-ART BMI, higher pre-ART levels of IL-6, sTNF-RI and RII, CXCL-10, sCD163 and hsCRP were associated with weight gain. Association of weight gain with week 96 changes of these biomarkers differed by sex; women who gained weight had smaller declines in most measured biomarkers compared to men who gained. CONCLUSIONS: Among women, weight gain is associated with attenuated decline in several immune activation markers following ART initiation. Clinical Trials Registration. NCT00811954 and NCT00811954.

Using Wearable Sensor Technology to Measure Motion Complexity in Infants at High Familial Risk for Autism Spectrum Disorder.

BACKGROUND: Motor dysfunction has been reported as one of the first signs of atypical development in infants at high familial risk for autism spectrum disorder (ASD) (HR infants). However, studies have shown inconsistent results regarding the nature of motor dysfunction and whether it can be predictive of later ASD diagnosis. This is likely because current standardized motor assessments may not identify subtle and specific motor impairments that precede clinically observable motor dysfunction. Quantitative measures of motor development may address these limitations by providing objective evaluation of subtle motor differences in infancy. METHODS: We used Opal wearable sensors to longitudinally evaluate full day motor activity in HR infants, and develop a measure of motion complexity. We focus on complexity of motion because optimal motion complexity is crucial to normal motor development and less complex behaviors might represent repetitive motor behaviors, a core diagnostic symptom of ASD. As proof of concept, the relationship of the motion complexity measure to developmental outcomes was examined in a small set of HR infants. RESULTS: HR infants with a later diagnosis of ASD show lower motion complexity compared to those that do not. There is a stronger correlation between motion complexity and ASD outcome compared to outcomes of cognitive ability and adaptive skills. CONCLUSIONS: Objective measures of motor development are needed to identify characteristics of atypical infant motor function that are sensitive and specific markers of later ASD risk. Motion complexity could be used to track early infant motor development and to discriminate HR infants that go on to develop ASD.

Leg Movement Rate Pre- and Post-Kicking Intervention in Infants with Down Syndrome.

AIM: Children with Down syndrome (DS) have delayed development and atypical movements including kicking. We hypothesized that a kicking intervention would significantly increase leg movement rate. METHODS: Nine infants, 3-5 months old, with DS used a commercially available toy that encouraged kicking. The intervention was administered in their home for 20 minutes, 5 days a week, for 8 weeks. Leg movement rate was measured using Opal wearable sensors before and after the intervention. At post-test, a secondary analysis compared infants with DS to infants with typical development (TD). RESULTS: Average leg movement rate increased significantly from pre to post intervention, from 2253 to 2645 movements per hour of awake time (p = 0.049). Compared to data from nine infants with TD, infants with DS had a significantly lower movement rate post intervention (p = 0.002). CONCLUSION: The infants with DS demonstrated a higher leg movement rate following an in-home kicking intervention.

Collecting Infant Environmental and Experiential Data Using Smartphone Surveys.

We propose that the collection of infant experiential and environmental data using smartphone surveys has the potential to fill a gap in foundational and clinical knowledge. To achieve this, these data need to be collected in a systematic way that is translatable globally. We can then begin to understand differences in child development and physical therapy from a variety of cultures and traditions. An infant's development is shaped by experiences in everyday life, and everyday experiences vary around the world. Hence, it is important to quantify these experiences to better understand variability in developmental trajectories. Recent increase in smartphone access has made the capability of collecting infant experiential data more feasible around the world. We provide examples and suggestions for ways in which experiential and environmental data can be collected for future practice.

How Many Days are Necessary to Represent Typical Daily Leg Movement Behavior for Infants at Risk of Developmental Disabilities?

BACKGROUND: Movement characteristics can differentiate between infants at risk and infants with typical development. However, it is unknown how many days are needed to accurately represent typical daily behavior for infants at risk of developmental disabilities when using wearable sensors. To consider the balance between participant burden and the amount of data collected and optimizing the efficiency of data collection, our study determined (1) how many days were necessary to represent typical movement behavior for infants at risk of developmental disabilities and (2) whether movement behavior was different on weekend days and weekdays. METHODS: We used Opal wearable sensors to collect at least 5 days of 11 infants' leg movement data. The standard (average of 5 days) was compared with four methods (average of the first 1/2/3/4 days) using the Bland-Altman plots and the Spearman correlation coefficient. We also compared the data from the average of 2 weekend days to the average of the first 2 weekdays for 8 infants. RESULTS: The Spearman correlation coefficient comparing the average of the first 2 days of data and the standards were all above 0.7. The absolute differences between them were all below 10% of the standards. The Bland-Altman plots showed more than 90% of the data points comparing the average of 2 days and the standards fell into the limit of agreement for each variable. The absolute difference between weekend days and weekdays for the leg movement rate, duration, average acceleration, and peak acceleration was 15.2%, 1.7%, 6.8% and 6.3% of the corresponding standard, respectively. CONCLUSION: Our results suggest 2 days is the optimal amount of data to represent typical daily leg movement behavior of infants at risk of developmental disabilities while minimizing participant burden. Further, leg movement behavior did not differ distinctly across weekend days and weekdays. These results provide supportive evidence for an efficient amount of data collections when using wearable sensors to evaluate movement behavior in infants at risk of developmental disabilities.

Introduction to Cystic Fibrosis for Mental Health Care Coordinators and Providers: Collaborating to Promote Wellness.

To maximize health, individuals with cystic fibrosis (CF) follow a complex, burdensome daily care regimen. Managing CF is associated with a range of significant biopsychosocial challenges and places individuals with CF, and their caregivers, at greater risk for developing anxiety and depression. To promote wellness and address the potential barriers that affect management of this complex chronic illness, many individuals would benefit from treatment from a behavioral health provider. Social workers within multidisciplinary CF care teams are well positioned to respond to this need, and an expanding number of social workers serving as behavioral health providers in the community will be sought as a resource to provide treatment to this population. This article serves as a primer for social workers to maximize knowledge of the psychosocial and potential behavioral health needs of individuals with CF across the life span. To best support individuals with CF, authors describe the disease-specific manifestations and outline the numerous potential clinical targets for social work to promote wellness. The article concludes by highlighting the importance of communication with the medical team and considerations for effective collaborative care.

Sensor Measures of Symmetry Quantify Upper Limb Movement in the Natural Environment Across the Lifespan.

Knowledge of upper limb activity in the natural environment is critical for evaluating the effectiveness of rehabilitation services. Wearable sensors allow efficient collection of these data and have the potential to be less burdensome than self-report measures of activity. Sensors can capture many different variables of activity and daily performance, many of which could be useful in identifying deviation from typical movement behavior or measuring outcomes from rehabilitation interventions. Although it has potential, sensor measurement is just emerging, and there is a lack of consensus regarding which variables of daily performance are valid, sensitive, specific, and useful. We propose that symmetry of full-day upper limb movement is a key variable. We describe here that symmetry is valid, robustly observed within a narrow range across the lifespan in typical development, and shows evidence of being different in populations with neuromotor impairment. Key next steps include the determination of sensitivity, specificity, minimal detectable change, and minimal clinically important change/difference. This information is needed to determine whether an individual belongs to the typical or atypical group, whether change has occurred, and whether that change is beneficial.

Quantifying Caregiver Movement when Measuring Infant Movement across a Full Day: A Case Report.

There is interest in using wearable sensors to measure infant movement patterns and physical activity, however, this approach is confounded by caregiver motion. The purpose of this study is to estimate the extent that caregiver motion confounds wearable sensor data in full-day studies of infant leg movements. We used wearable sensors to measure leg movements of a four-month-old infant across 8.5 hours, during which the infant was handled by the caregiver in a typical manner. A researcher mimicked the actions of the caregiver with a doll. We calculated 7744 left and 7107 right leg movements for the infant and 1013 left and 1115 right "leg movements" for the doll. In this case, approximately 15% of infant leg movements can be attributed to background motion of the caregiver. This case report is the first step toward removing caregiver-produced background motion from the infant wearable sensor signal. We have estimated the size of the effect and described the activities that were related to noise in the signal. Future research can characterize the noise in detail and systematically explore different methods to remove it.

Immediate Effect of Positioning Devices on Infant Leg Movement Characteristics.

PURPOSE: To determine the immediate effects of constraining or encouraging positioning devices on leg movement of infants with typical development (TD) and at-risk for developmental delay (AR). METHODS: Twenty-six infants (13 TD, 13 AR) were placed in the supine position, a jungle gym, or a car seat. Movement sensors on infants' ankles measured acceleration and angular velocity. We calculated the number of leg movements, peak acceleration, and peak rotational rate of each leg movement. A 2 (group) × 3 (condition) analysis of variance with repeated measures on condition tested for a group effect, a condition effect, and a group by condition interaction for leg movement quantity, average peak acceleration, and average peak rotation. RESULTS: Leg movement quantity and average peak acceleration were significantly lower for the car seat condition compared with the supine position or the gym. CONCLUSIONS: Positioning device use has an immediate effect on infant leg movement characteristics. Long-term effects remain unknown.