Environmental Support and the Development of Grasp in Infants

Abstract

This study examines the acquisition of internal stability as it relates to the development of prehension in normal infants. Thirty-two subjects, 7 to 14 months of age, were observed grasping Cheerios from styrene surfaces that provided different amounts of support to the infants' hands. The subjects were scored on the grasp patterns they used and on their success in securing a Cherrio without dislodging the styrene surface from a platform. Success increased with age, thus demonstrating a developmental progression in the acquisition of upper extremity internal stability. Consistency of grasp also increased with age. Whereas the youngest infants (7 to 8 months old) reverted to immature grasp patterns on the less stable surfaces, the oldest infants (13 to 14 months old) used mature pincer grasp patterns consistently. Infants 10 to 11 months old seemed to be in a transitional stage between the variability of grasp seen in the youngest infants and the consistency achieved by the oldest group.

Enhancing Prehension in Infants and Children

“…While some studies provide solid evidence that intervention for infants and young children is effective in improving postural control and prehensile skill (e.g., Case-Smith, 1996Hadders-Algra et al, 1996;Hirschel et al, 1990) others do not (Law et al, 1997). Therefore, further research is needed to identify optimal methods of intervention and practice schedules.…”

“…Power grips transmit forces from the fingers and thumb against the palm and precision grips transmit forces between the fingers and thumb (Napier, 1956). As experience widens and the connection between the motor neuronal pool and cortex is strengthened, isolated finger movement and precision grip patterns such as the pincer grasp develop (Hirschel et al, 1990;Forssberg et al, 1991).…”

Prehension

“…An infant can usually release a block into a small container by 12 months and release a pellet into a small container by 15 months. 62 Ball throwing is an example of release that improves in control and accuracy as the infant moves into childhood.…”