The aim of this systematic literature review was to examine and discuss studies that investigated reaching in preterm infants during the first year of life. Databases were searched using keywords such as reaching, grasping, preterm, and premature, in addition to specific terms from the Medical Subject Headings (MeSH) (motor skills, infant, movement, premature birth, hands) regardless of year of publication. One hundred thirty-five studies were identified, 9 of which were selected. The results showed that preterm infants adopt strategies (bimanual reaches and reaches with less rectilinear trajectories toward an object in motion, reaches with semi-open and open hand, reaches at lower speeds, with increased movement units, and variable postural muscle activity) compared with full-term infants. However, the results on how intrinsic factors (e.g., prematurity) and extrinsic factors (e.g., body position, physical properties of the object) influence early reaching are still limited.
Elaine Leonezi Guimarães, Andréa Baraldi Cunha, Daniele de Almeida Soares and Eloisa Tudella
Joan E. Deffeyes, Regina T. Harbourne, Wayne A. Stuberg and Nicholas Stergiou
Sitting is one of the first developmental milestones that an infant achieves. Thus measurements of sitting posture present an opportunity to assess sensorimotor development at a young age. Sitting postural sway data were collected using a force plate, and the data were used to train a neural network controller of a model of sitting posture. The trained networks were then probed for sensitivity to position, velocity, and acceleration information at various time delays. Infants with typical development developed a higher reliance on velocity information in control in the anterior-posterior axis, and used more types of information in control in the medial-lateral axis. Infants with delayed development, where the developmental delay was due to cerebral palsy for most of the infants in the study, did not develop this reliance on velocity information, and had less reliance on short latency control mechanisms compared with infants with typical development.
Marianne Jover, Mathilde Cellier and Celine Scola
In developmental research, infants are usually assumed to become active partners in interactions with their caregivers soon after birth (e.g., Gratier et al., 2015 ). Very early on, dyadic interactions move from being simply alternating turns to being coordinated expressions in time, which
Ivan A. Trujillo-Priego, Judy Zhou, Inge F. Werner, Weiyang Deng and Beth A. Smith
associated with improved motor development ( Carson et al., 2017 ). Studying infant activity and movement in the daily environment is important for determining optimal practices for promoting infant health and development. Wearable sensors can be used to characterize the quantity, acceleration, and type of
Weiyang Deng, Douglas L. Vanderbilt and Beth A. Smith
With the development of obstetric and neonatal medicine, the mortality rate of high-risk infants has decreased ( Alexander et al., 2003 ). Hence, an increasing number of infants with different kinds of neuromuscular impairments survive. These infants are classified at or before birth as at risk for
Janet L. Hauck, Isabella T. Felzer-Kim and Kathryn L. Gwizdala
The persistent motor delays present in infants with Down syndrome (DS) can become constraints to safety, quality of life, and family convenience. Such delays prolong the time when an infant is physically dependent on caregivers. For instance, an infant who cannot independently roll must be
Daniela Corbetta, Rebecca F. Wiener, Sabrina L. Thurman and Emalie McMahon
The emergence of reaching around 3 to 5 months of age corresponds to a special moment in the infant’s life where the gaze directed toward an object is accompanied by an arm extension also directed toward that same object. This moment, when gaze and arm intersect around a common aim, marks a
Kelsey Lucca, David Gire, Rachel Horton and Jessica A. Sommerville
predictor of academic achievement ( Duckworth & Gross, 2014 ; Duckworth, Peterson, Matthews, & Kelly, 2007 ). Developmental psychologists have examined persistence because it provides a window into what infants know about the world, and what they care about ( Leonard, Lee, & Schulz, 2017 ; Lucca
Robert K. Jensen, Tina Treitz and Han Sun
The purpose of the study was to use the elliptical cylinder model adapted for infants (Sun & Jensen, 1994) with a cross-sectional sample to select appropriate multiple linear regression equations for predicting masses and nonlinear regression equations for predicting principal moments of inertia (Yeadon & Morlock, 1989). The linear and nonlinear predictions were evaluated with an independent cross-validation sample of infants and a sample where inertias ranged below and above the cross-sectional sample. The cross-validation for masses was compared to a cross-validation of four linear regressions for masses developed by Schneider and Zernicke (1992). It is recommended that the linear regression equations developed in this study be used to predict infant segment masses. It is also recommended that the nonlinear regression equations developed in this study be used to predict the principal moments of inertia of all infant segments, other than head Ix and lower trunk Ix and Iy.
James R. Chagdes, Joshua J. Liddy, Amanda J. Arnold, Laura J. Claxton and Jeffrey M. Haddad
spectrum disorder ( Nickel, Thatcher, Keller, Wozniak, & Iverson, 2013 ), and capturing motor delays in infants born preterm ( Bucci et al., 2017 ). This expanding literature base strongly suggests that important diagnostic and maturational information is present and measurable in the postural dynamics of