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Updated: Jul 11, 2025
Frame-by-Frame Video Analysis of Idiosyncratic Reach-to-Grasp Movements in Humans
Published on: January 15, 2018
Late preterm and very preterm infants differ in the acquisition time and quantity of reaches with grasping at
Andressa Lagoa Nascimento França1, Priscila Maier Teruia2, Amanda de Oliveira Arguelho3
1Graduate Program in Health and Development, Faculty of Medicine, Federal University of Mato Grosso do Sul, Campo Grande, Brazil.
Insights
Very preterm infants show delayed reaching onset and fewer grasping instances compared to late preterm infants. These differences are linked to lower birth weight and longer hospital stays, highlighting clinical impacts on infant motor development.
Area of Science:
- Developmental Pediatrics
- Infant Motor Development
- Neonatal Research
Background:
- Manual reaching is crucial for infant environmental interaction.
- Preterm birth can negatively impact reaching development.
- The influence of prematurity degree on reaching is not well understood.
Purpose of the Study:
- To compare reaching acquisition and behavior in late preterm versus very preterm infants.
- To investigate the impact of gestational age and clinical factors on reaching development.
Main Methods:
- Observational, comparative study of 24 infants post-reaching onset.
- Two groups: 12 late preterm (35.55 ± 0.67 GW) and 12 very preterm (30.60 ± 0.05 GW).
- Reaching behavior observed for 2 minutes with a toy; birth weight and hospital stay recorded.
Main Results:
- Very preterm infants had a later reaching onset.
- Late preterm infants exhibited a higher proportion of reaches with grasping.
- Lower birth weight and longer hospital stay in very preterm infants influenced these outcomes.
Conclusions:
- Very preterm infants face challenges in reaching acquisition and grasping compared to late preterm infants.
- Proportions of proximal and distal reaching adjustments were similar between groups.
- Clinical variables significantly influenced the observed differences in reaching development.
Introduction:
The onset of manual reaching allows the expansion of the infant's interaction with the environment. When born preterm, infants become vulnerable to problems in the development of reaching. However, it is still unknown whether there are differences in reaching according to the degree of prematurity.
Objective:
This study aimed to explore the differences in reaching acquisition and behavior between late preterm and very preterm infants, as well as whether age and clinical variables influence the results.
Method:
This is an exploratory, comparative, observational study. In total, 24 infants were included soon after reaching onset; 12 infants were born late preterm (35.55 ± 0.67 gestational weeks) and 12 very preterm (30.60 ± 0.05 gestational weeks). Infants were placed in a baby seat, and a toy was placed at a reachable distance for 2 min. Reaching behavior was the primary variable; birth weight and length of hospital stay were secondary variables.
Results:
The age of reaching onset was higher in the very preterm group. The proportion of reaches with grasping was higher in the late preterm group. These differences were affected by the lower birth weight and longer length of hospital stay in the very preterm group. The proportions of proximal and distal adjustments did not differ between groups.
Conclusion:
Very preterm infants presented disadvantages in the acquisition time and the number of reaches with grasping, but not in the proportions of proximal and distal adjustments of reaching, relative to late preterm infants. Group differences were influenced by clinical variables.
