The Development of Upper Limb Movements: From Fetal to Post-Natal Life

Stefania Zoia,Umberto Castiello,Giuseppina D’Ottavio,Marina Biancotto,Maria Bulgheroni,Laura Blason,Alessio Avenanti

doi:10.1371/journal.pone.0080876

Stefania Zoia, Umberto Castiello + Show 5 more

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https://doi.org/10.1371/journal.pone.0080876

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Abstract

BackgroundThe aim of this longitudinal study was to investigate how the kinematic organization of upper limb movements changes from fetal to post-natal life. By means of off-line kinematical techniques we compared the kinematics of hand-to-mouth and hand-to-eye movements, in the same individuals, during prenatal life and early postnatal life, as well as the kinematics of hand-to-mouth and reaching-toward-object movements in the later age periods.Methodology/Principal FindingsMovements recorded at the 14th, 18th and 22nd week of gestation were compared with similar movements recorded in an ecological context at 1, 2, 3, 4, 8, and 12 months after birth. The results indicate a similar kinematic organization depending on movement type (i.e., eye, mouth) for the infants at one month and for the fetuses at 22 weeks of gestation. At two and three months such differential motor planning depending on target is lost and no statistical differences emerge. Hand to eye movements were no longer observed after the fourth month of life, therefore we compared kinematics for hand to mouth with hand to object movements. Results of these analyses revealed differences in the performance of hand to mouth and reaching to object movements in the length of the deceleration phase of the movement, depending on target.Conclusion/SignificanceData are discussed in terms of how the passage from intrauterine to extra-uterine environments modifies motor planning. These results provide novel evidence of how different types of upper extremity movements, those directed towards one’s own face and those directed to external objects, develop.

Highlights

In human development, hand-mouth contact is among the earliest cases of a sustained behavioral pattern that integrates two separate motor systems
Based on observations reported in the literature, the early development of hand-mouth coordination is shown to be closely related to the development of other sensory motor systems, in particular eyehand coordination (e.g., [5])
In the present longitudinal study, we explored this transition by investigating the differences between hand-to-mouth movements during prenatal life and early postnatal life, and between hand-to-mouth and reaching-towardobject movements in the later age periods

Summary

Introduction

Hand-mouth contact is among the earliest cases of a sustained behavioral pattern that integrates two separate motor systems. Assessing the development of hand-mouth coordination after the newborn period investigates the changes observed between 2–5 months in the coordination of reaching and grasping [6] In these terms, handmouth integration changes developmentally, coming under the control of perceptual systems by 5 months of age when infants start to reach for [7,8,9,10], to grasp [11], and to bring the objects to the mouth [12,13]. By means of off-line kinematical techniques we compared the kinematics of hand-to-mouth and hand-to-eye movements, in the same individuals, during prenatal life and early postnatal life, as well as the kinematics of hand-to-mouth and reaching-toward-object movements in the later age periods

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