Motor Activity In Infants Research Articles

Motor Overflow during Reaching in Infancy: Quantification of Limb Movement Using Inertial Motion Units.

Early in life, infants exhibit motor overflow, which can be defined as the generation of involuntary movements accompanying purposeful actions. We present the results of a quantitative study exploring motor overflow in 4-month-old infants. This is the first study quantifying motor overflow with high accuracy and precision provided by Inertial Motion Units. The study aimed to investigate the motor activity across the non-acting limbs during goal-directed action. To this end, we used wearable motion trackers to measure infant motor activity during a baby-gym task designed to capture overflow during reaching movements. The analysis was conducted on the subsample of participants (n = 20), who performed at least four reaches during the task. A series of Granger causality tests revealed that the activity differed depending on the non-acting limb and the type of the reaching movement. Importantly, on average, the non-acting arm preceded the activation of the acting arm. In contrast, the activity of the acting arm was followed by the activation of the legs. This may be caused by their distinct purposes in supporting postural stability and efficiency of movement execution. Finally, our findings demonstrate the utility of wearable motion trackers for precise measurement of infant movement dynamics.

Infant temperament prospectively predicts general psychopathology in childhood.

Recent models of psychopathology suggest the presence of a general factor capturing the shared variance among all symptoms along with specific psychopathology factors (e.g., internalizing and externalizing). However, few studies have examined predictors that may serve as transdiagnostic risk factors for general psychopathology from early development. In the current study we examine, for the first time, whether observed and parent-reported infant temperament dimensions prospectively predict general psychopathology as well as specific psychopathology dimensions (e.g., internalizing and externalizing) across childhood. In a longitudinal cohort (N = 291), temperament dimensions were assessed at 4 months of age. Psychopathology symptoms were assessed at 7, 9, and 12 years of age. A bifactor model was used to estimate general, internalizing, and externalizing psychopathology factors. Across behavioral observations and parent-reports, higher motor activity in infancy significantly predicted greater general psychopathology in mid to late childhood. Moreover, low positive affect was predictive of the internalizing-specific factor. Other temperament dimensions were not related with any of the psychopathology factors after accounting for the general psychopathology factor. The results of this study suggest that infant motor activity may act as an early indicator of transdiagnostic risk. Our findings inform the etiology of general psychopathology and have implications for the early identification for children at risk for psychopathology.

Caregiver perception of hand function in infants with cerebral palsy: psychometric properties of the Infant Motor Activity Log.

To evaluate the properties of the Infant Motor Activity Log (IMAL), a caregiver-report for frequency and quality of use of more affected upper extremity in infants with neurological and functional impairments. This was a prospective cohort study of 66 children (34 females, 32 males) aged 6 to 24months (mean age [SD] 13.7mo [5.3]) with neurological and functional impairments and a confirmed cerebral palsy diagnoses after 2years, and 51 age-matched typically developing children. The IMAL was administered at baseline and 4weeks later. Typically developing infants were tested with randomly assigned 'more affected' upper extremity. Psychometric properties were evaluated using Spearman's correlation coefficient, Cronbach's alpha, and Jonckheere-Terpstra tests. In the children with impairments, the IMAL showed internal consistency (alpha≥0.88) for the How Well Scale (HWS) and How Often Scale (HOS). Test-retest reliability was 0.64 (HOS) and 0.70 (HWS), demonstrating stability over time. Correlation with Bayley Scales of Infant and Toddler Development, Third Edition more affected arm raw scores were 0.70 (HOS) and 0.72 (HWS) (p<0.001) demonstrating construct validity. Both scale scores decreased with increasing Gross Motor Function Classification System and Mini-Manual Ability Classification System (p<0.001) levels, supporting discriminative validity. Discrimination between typically developing infants and infants with impairments was high (HWS: area under the receiver operating characteristic curve [AUC] 0.96, 95% confidence interval [CI] 0.94-0.99 and HOS AUC=0.95, CI 0.92-0.99). The IMAL is a valid and reliable discriminative caregiver measure of upper limb performance and may complement measures of capacity in infants with neurological and functional impairments. The Infant Motor Activity Log (IMAL) is a valid and reliable measure of caregiver perception of upper limb function. The IMAL fills a measurement gap for infant motor performance in children with impairments. The IMAL discriminates among motor function levels.

Infants’ Motor Activity During a Mother–Infant Interaction Alternating Silent and Singing Phases

Infants interact with their caregivers, using visual contact, smiling, vocalizations, and motor activity. Most of the studies on infant motor activity during dyadic interaction provided qualitative microanalyses. Few documented changes in infants’ general motor activity when facing social stimuli, but the movement analyses were carried out over large time windows. Following on from a previous study, we sought to explore rapid variations in motor activity during an interaction between mothers and their 6-month-old infants. The interaction featured short alternating silent and singing phases. Results showed that infants’ head, hand, and foot motor activity was related to their mothers’ behavior. Head movements, in particular, decreased during the songs and increased between them. The interindividual variability was strong at the hand and foot level and a k-mean cluster analysis showed three different group tendencies. Head stillness certainly expressed the infants’ attentional engagement in the interaction. Hand and foot movements appeared to be more variable and, at the foot level, presumably depended on the mother–infant communicative routines. Infants’ general motor activity could be an indicator of the infant’s engagement and reflect the dyad’s communicative routines during interactions.

Caregiver perception as an outcome measure: psychometric properties of the infant motor activity log in infants with asymmetric cerebral palsy

Caregiver perception as an outcome measure: psychometric properties of the infant motor activity log in infants with asymmetric cerebral palsy

Detection of Infant Motor Activity During Spontaneous Kicking Movements for Term and Preterm Infants Using Inertial Sensors.

Spontaneous kicking in infants is one of the earliest displays of motor skills. Abnormalities observed in these displays are an important indicator of later abnormal neuromotor function. However, these abnormalities are not well defined and difficult to detect outside of direct clinical observation. To allow for extended, non-clinical observation of spontaneous kicking, IMU sensors are attached to the limb segments of the infant's legs. An activity detection algorithm is then used to quantify kicking activity derived from collected measurement data. This paper presents our method in detail and discusses results from kicking data acquired from term and low-risk preterm infants.

Infant temperament reactivity and early maternal caregiving: independent and interactive links to later childhood attention-deficit/hyperactivity disorder symptoms.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with origins early in life. There is growing evidence that individual differences in temperament reactivity are predictive of ADHD symptoms, yet little is known about the relations between temperament reactivity in early infancy and later ADHD symptoms or the combined effect of reactivity with early environmental factors on ADHD symptom development. Using a 9-year prospective longitudinal design, this study tested the independent and interactive contributions of infant reactivity and maternal caregiving behaviors (MCB) on parent- and teacher-reported childhood ADHD symptoms. Participants included 291 children (135 male; 156 female) who participated in a larger study of temperament and social-emotional development. Reactivity was assessed by behavioral observation of negative affect, positive affect, and motor activity during novel stimuli presentations at 4months of age. MCB were observed during a series of semistructured mother-infant tasks at 9months of age. Finally, ADHD symptoms were assessed by parent- and teacher-report questionnaires at 7 and 9years, respectively. Reactivity was predictive of ADHD symptoms, but results were sex specific. For boys, infant motor activity was positively predictive of later ADHD symptoms, but only at lower quality MCB. For girls, infant positive affect was positively predictive of later ADHDsymptoms at lower quality MCB, and-unexpectedly-infant positive affect and motor activity were negatively predictive of later ADHD symptoms at higher quality MCB. These results point to early parenting as a moderating factor to mitigate temperament-related risk for later ADHD, suggesting this as a potential intervention target to mitigate risk for ADHD among reactive infants.

Infant motor activity during sleep: Simultaneous use of two actigraphs comparing right and left legs

Motor asymmetry during the first hours of sleep documented in adults found higher activity in the non-dominant limb. The stage of development at which such asymmetries first appear is unknown. Twenty healthy infants were followed from 7 to 12months of age, at 3-week intervals, comparing motor activity of the right and left legs during sleep using twin actigraphs (AMI). Hour-by-hour analysis of the first seven hours of nocturnal sleep found no consistent difference in activity levels between the right and left legs. Using the standard algorithm for infants, which provides an overall estimate of sleep quality, revealed discrepancies in night waking episodes (Right versus Left) in 33% of the nights. Results pertaining to leg movement suggest that motor asymmetry is not yet present during the first year of life. However, given the large discrepancies in the detection of night waking, further investigation of the developmental course of circadian motor asymmetry is warranted.

Motor activity at age one year does not predict ADHD at seven years

We have examined the predictive utility of motor activity in infancy towards diagnosis of attention deficit hyperactivity disorder (ADHD) in later childhood. We conducted a nested case-control study using videos of infants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Sixty videos of children who received any Development and Well-being Assessment (DAWBA) psychiatric diagnosis at age 91 months (including 16 with ADHD) plus two controls per case were selected for data analysis. Body movements were measured at age one year: associations between motor activity-derived variables using factor analysis, and later ADHD diagnoses were sought. No significant association was found between infant motor activity and later ADHD. A positive association between motor activity and inattentive ADHD was found in males. Motor activity at age one year did not predict ADHD at age seven years. The positive association with inattentive ADHD in males requires further investigation.

Very early observational predictors of psychiatric disorder

<h3>Aims</h3> This series of studies is based on a 10% sub sample of infants from a prospective longitudinal general population cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC). <h3>Methods</h3> We examined 180 videos of parent-infant interaction: 60 with infants aged 12 months who later proved to have a psychiatric disorder at seven years; and 120 randomly selected sex-matched controls. The case group included 27 children with any oppositional or conduct disorder (ODD/CD), 16 with attention- deficit/hyperactivity disorder (ADHD), 6 with pervasive development disorder/autism, and 28 with any anxiety or depressive disorder. Raters (blind to case or control status) made a series of observations which were later assessed for their value in predicting psychopathology at age 7: two behavioural coding systems (Mellow Parenting and CARE Index); measures of infant motor activity; clinical assessments by two groups of senior clinicians; holistic assessment of parent-infant interaction; and specific individual parental and infant behaviours. <h3>Results</h3> Positive parenting behaviours as assessed by the Mellow Parenting system predicted reduced risk of development of oppositional/conduct disorders. The Infant Passivity subscale of the CARE Index appeared to predict autism. Clinical raters could not reliably predict later psychopathology and there was limited agreement between teams of raters. Infant motor activity did not predict psychopathology. The level of adult activity and vocalisation predicted whether infants would be diagnosed with ADHD, ODD/CD, and any anxiety disorder at seven years of age. <h3>Conclusion</h3> There are robust early indicators of later onset of child psychopathology, identifiable in early parent-infant interaction at 12 months.

Assessment of Circadian Rhythms of Both Skin Temperature and Motor Activity in Infants During the First 6 Months of Life

The authors developed a method useful for home measurement of temperature, activity, and sleep rhythms in infants under normal-living conditions during their first 6 mos of life. In addition, parametric and nonparametric tests for assessing circadian system maturation in these infants were compared. Anthropometric parameters plus ankle skin temperature and activity were evaluated in 10 infants by means of two data loggers, Termochron iButton (DS1291H, Maxim Integrated Products, Sunnyvale, CA) for temperature and HOBO Pendant G (Hobo Pendant G Acceleration, UA-004-64, Onset Computer Corporation, Bourne, MA) for motor activity, located in special baby socks specifically designed for the study. Skin temperature and motor activity were recorded over 3 consecutive days at 15 days, 1, 3, and 6 mos of age. Circadian rhythms of skin temperature and motor activity appeared at 3 mos in most babies. Mean skin temperature decreased significantly by 3 mos of life relative to previous measurements (p = .0001), whereas mean activity continued to increase during the first 6 mos. For most of the parameters analyzed, statistically significant changes occurred at 3–6 mos relative to 0.5–1 mo of age. Major differences were found using nonparametric tests. Intradaily variability in motor activity decreased significantly at 6 mos of age relative to previous measurements, and followed a similar trend for temperature; interdaily stability increased significantly at 6 mos of age relative to previous measurements for both variables; relative amplitude increased significantly at 6 mos for temperature and at 3 mos for activity, both with respect to previous measurements. A high degree of correlation was found between chronobiological parametric and nonparametric tests for mean and mesor and also for relative amplitude versus the cosinor-derived amplitude. However, the correlation between parametric and nonparametric equivalent indices (acrophase and midpoint of M5, interdaily stability and Rayleigh test, or intradaily variability and P1/Pultradian) despite being significant, was lower for both temperature and activity. The circadian function index (CFI index), based on the integrated variable temperature-activity, increased gradually with age and was statistically significant at 6 mos of age. At 6 mos, 90% of the infants' rest period coincided with the standard sleep period of their parents, defined from 23:00 to 07:00 h (dichotomic index I < O; when I < O = 100%, there is a complete coincidence between infant nocturnal rest period and the standard rest period), whereas at 15 days of life the coincidence was only 75%. The combination of thermometry and actimetry using data loggers placed in infants' socks is a reliable method for assessing both variables and also sleep rhythms in infants under ambulatory conditions, with minimal disturbance. Using this methodological approach, circadian rhythms of skin temperature and motor activity appeared by 3 mos in most babies. Nonparametric tests provided more reliable information than cosinor analysis for circadian rhythm assessment in infants. (Author correspondence: elvirada@um.es)

P85: Overweight in Infants: Where can Nutrition Education Make a Difference?

Recent data indicate that rates of overweight in low-income Hispanic and black infants are significantly higher than for whites. The purpose of the present study was to explore whether diet (energy intake) or activity (energy expenditure) is more strongly related to infants' Body Mass Index (BMI), and if other maternal factors may contribute to differences in BMI. Seventy-seven black and Latina mothers were recruited from a WIC Program, and they and their infants were observed in their homes at 3-, 6-, and 12-months postpartum. At each home visit trained observers scored maternal feeding style, caregivers completed 24-hour diet records, and infant motor activity was measured with actometers attached to their ankles for 24-hours. Using BMI-for-age percentile charts, 40% of the infants were > the 85th percentile at 12-months, with 21% of them at the 95th or above. Neither age at which solid foods were introduced, kilocalories ingested over 24 hours, or infant difficulty predicted infant weight at 1-year. However, 6-month maternal sensitivity to infant cues (r = -.22, P < .05) and infant activity while asleep (r = -.23, P < .05) were both inversely related to infant BMI at 12-months, while more dietary fat at 6-months predicted higher BMI at 12-months (r = .24, P < .05). These results suggest that nutrition education efforts with new mothers should attempt to improve their ability to read their infants' signals and monitor levels of fat in supplementary foods. Funded by NIH grant 1R03HD 39697-01A1 to the first author.

Spontaneous motor activity in human infants with iron-deficiency anemia

This study compared spontaneous motor activity in 6-month-old Chilean infants with or without iron-deficiency anemia (IDA) who were otherwise healthy. Activity was assessed in conjunction with polysomnographic recording during an afternoon nap in 11 infants with IDA and 15 with normal hemoglobin levels. All infants were given oral iron, and activity was reassessed at 12 and 18 months. Using actigraphs placed on the ankle, the frequency of movement units per minute was determined for each waking/sleep state. The total amount of time infants were in an alert-active state before and after the nap was used to calculate the proportion of movements/minute of waking. There were no differences between anemic and nonanemic infants in total recording time, duration of sleep, or motor activity during sleep. However, infants with IDA showed reduced motor activity during waking at all ages. The magnitude of the differences increased at 12 and 18 months. Thus, IDA was associated with reduced motor activity in infants even after iron treatment. It will be important to confirm these results in a larger sample and to determine the 24-h pattern of motor activity, since reduced motor activity may limit infants' opportunities to explore and learn from the social and physical environment.

The significance of high bone density in children

The significance of high bone density in children

Sex differences in motor activity during early infancy

Many studies conducted with children have reported a higher activity level in boys. However, very few studies bearing on infant motor activity have found significant sex differences, and no clear pattern of differentiation has emerged from these data. To further investigate the motor activity of boys and girls during early infancy, the durations and frequencies of their trunk and limb movements and of periods of inactivity and the vigor of their head and limb movements were compared within different situations at 2 1 2 and 5 months of age. The durations and frequencies of movements and of periods of inactivity did not differ substantially in boys and girls. The measures of vigor yielded more significant results, but no stable sex differences emerged. The contribution of physiological and environmental factors to the sexual differentiation of motor activity is discussed.

Heart rate estimates of motor activity in preterm infants

Heart rate (HR) and motor activity (MA) are related to one another through their common association with energy expenditure. To determine whether that relationship is sufficiently strong to predict MA from HR, 24 medically stable preterm infants were observed for two 1 2 -hour periods during which their heart beats were counted. Average activity and HR values were calculated for comparison periods of 5 to 30 min duration. Regardless of the duration of the comparison periods, the differences in HR between periods correlated positively and significantly with the concomitant difference in the infant's MA. When adjacent 1 2 -hour periods were compared, 85% of the variation in activity could be accounted for by HR. Change in HR thus appears to be a strong positive linear correlate of change in MA in the preterm infant.

An examination of the relationship between fetal movements and infant motor activity.

Fifty-one patients recorded fetal movement counts for several weeks, 29 while hospitalized for complications of pregnancy (group 1) and 22 with normal pregnancies and ambulant (group 2). The motor activity of group 1 neonates was examined 24-72 hours following delivery, using a partial Brazelton neonatal assessment scale. Group 2 infants were examined at age 10-12 months, using a method specially designed for this study to assess motor activity. No significant correlation was found between the mean number of fetal movements and the motor activity of neonates, versus those of one-year-old infants. These findings suggest that fetal movements are most probably influenced by numerous factors differing from those influencing the motor activity of the neonate and infant.