Longitudinal study of unimanual actions and grasping forces during infancy (original) (raw)
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Development of manipulative hand movements during the second year of life
Early Human Development, 2003
Background: Developmental testing in children is concerned mainly with a pass or fail on tasks such as grasping, manipulating and inserting. Knowledge about the qualitative development of hand movements in young children is scarce. Aim: We studied the qualitative development of manipulative hand movements in 14-, 18-and 25-month-olds. Study design and subjects: Twentysix children were videoed during grasping, manipulating and inserting cubes into a cup or box and pegs into a peg-board. Results: We found clear-cut, object-related results. The right hand was used mainly to grasp, manipulate and insert the pegs, while no hand preference was found for the cube. Generally, the quality of grasping and inserting did not change with age. At 18 months, the performance was more optimal if the children used pegs rather than cubes. The adjustment of hand opening became more adapted with increasing age when grasping the cubes; this was not observed for the pegs. Associated movements occurred less during pegging than while playing with the cubes. A variety of patterns were used for pegging. Besides a difference in hand preference between girls and boys, some patterns became more prominent with increasing age. The success rate increased with age but was independent of the pattern used. Conclusion: This study stresses the need of a clear understanding of the entire spectrum of normal motor development. This knowledge forms the basis on which abnormalities, even of such common movement patterns as grasping, manipulating and inserting, can be reliably diagnosed in neurologically impaired infants and children. D
Palmar grasp behavior in full-term newborns in the first 72hours of life
Physiology & Behavior, 2015
Background: The palmar grasp behavior is one of the items of an infant's routine neurological tests. Its exacerbated presence after the fifth month of age or absence in the first day after birth is an important sign of neuro-sensorimotor disorders. This study aimed to describe the palmar grasp behavior of full-term newborns in the first 72 h of life. Methods: This nonrandomized cross-sectional developmental study included 219 typical newborns aged 12-24 h, 25-48 h and 49-72 h. Three measurements were performed with newborns in the supine position, recording the palmar grasp time and strength. Statistical analysis was applied with significant level of p b 0.05. Results: Higher palmar grasp strength was observed in newborns aged 49-72 h compared to newborns aged 12-24 h and 25-48 h (F = 7.42, p = 0.01). There was significant difference in palmar grasp strength between hands (F = 6.55, p = 0.01), only in 12-24 h, with greater strength in the left hand (t = −2.43, p = 0.01), and difference in palmar grasp between strength (F = 18.7, p = 0.01) with greater strength in females (t = −5.40, p = 0.01) only at the age 48-72 h. Conclusions: It was concluded that the palmar grasp behavior modifies in the first 72 h of life.
Preparation for grasping an object: A developmental study
Journal of Experimental Psychology Human Perception and Performance, 1988
The development of visually controlled grasping actions was studied in two experiments. An optoelectronic technique (SKLSHOT) was used to monitor the opening and closing of the hand during reaching actions by measuring the change in the distance between thumb and index finger. The purpose of Experiment 1 was to establish an adult criterion for the development. It was shown that adults started closing the hand around the target well before touch and that the timing was dependent on the size of the target. The hand started to close earlier when grasping a small rather than a large target. In addition, the degree of hand opening was also less for a small than for a large target. In Experiment 2 it was shown that infants who were 5-6, 9, and 13 months of age also controlled their grasping actions visually and started closing the hand around the target in anticipation of the encounter rather than as a reaction to the encounter. However, the strategy of the two younger age groups was different from that of adults. They started closing the hand closer to the time of contact with the target than did the 13-month-olds, who were comparable to adults in this respect. The timing was not dependent on the size of the target in any of the infant groups. In all age groups, reaching and grasping were most commonly organized in a continuous way; that is, the hand started to close without any interruption in the approach. The opening of the hand was found to be adjusted to target size in the 9-and 13-month-olds but not in the 5-6 month olds. In the present article we are concerned with the early development of reaching and grasping into one unified action in which the grasping of the target is prepared in advance, during the approach of it. To ensure a smooth and efficient grasp, the reaching hand needs to prepare itself for the encounter with the object. These preparations are visually controlled. They may be of two kinds. First, there are spatial adjustments of the reaching hand to the orientation, form, and size of the object. Second, the securing of the target should be timed in such a way that the hand starts to close around the target in anticipation of, not as a reaction to, the encounter of the object. Earlier studies have shown that at least some preparatory spatial adjustments are present early in development. The infant adjusts the orientation of the hand to the orientation of the object before it is encountered (Lockman, Ashmead, & Bushnell, 1984; Hofsten & Fazel-Zandy, 1984; Morrongiello & Rocca, 1986). Hofsten and Fazel-Zandy (1984) and Morrongiello and Rocca (1986) found that 5-month-old infants already made such preparatory adjustments of hand orientation. These adjustments are of great advantage to the child. They need to be done beforehand if the hand is going to close around the object in an adequate way. Funds for this investigation were provided by grants to Claes von Hofsten from the Swedish Council for Research in the Humanities and Social Sciences. We wish to thank the parents and the children for helpful cooperation in the laboratory, and the nurses at Barnavardscentralen for their cooperation in recruiting subjects. We would also like to thank Jorma Putaansuu, Anwer Siddiqui, and Kerstin Ardahl for helpful assistance at various stages of the project.
Development of reaching in infancy
Experimental Brain Research, 2005
The development of reaching for stationary objects was studied longitudinally in 12 human infants: 5 from the time of reach onset to 5 months of age, 5 from 6 to 20 months of age, and 2 from reach onset to 20 months of age. We used linear mixed-effects statistical modeling and found a gradual slowing of reach speed and a more rapid decrease of movement jerk with increasing age. The elbow was essentially locked during early reaching, but was prominently used by 6 months. Differences between infants were distributed normally and no evidence of different types of reachers was found. The current work combined with other longitudinal studies of infant reaching shows that the increase in skill over the first 2 years of life is seen, not by an increase in reaching speed, but by an increase in reach smoothness. By the end of the second year, the overall speed profile of reaching is approaching the typical adult profile where an early acceleration of the hand brings the hand to the region of the target with a smooth transition to a lower-speed phase where grasp is accomplished.
Infant Behavior and Development, 2009
The goal of this study was to investigate some of the visuo-motor factors underlying an infant's developing ability to grasp a laterally-moving object. In particular, hand preference, midline crossing, and visual-field asymmetry were investigated by comparing performance as a function of the object's direction of motion. We presented 6-, 8-, and 10-month-old infants with a graspable object, moving in a circular trajectory in the horizontal plane. Sixmonth-old infants reached for the object with the ipsilateral hand and grasped it with the contralateral hand. Eight-month-old infants showed a strong right-hand bias for both reaching and grasping. Ten-month-old infants showed a greater diversity of strategy use including bimanual and successful ipsilateral grasping following ipsilateral reaching in both directions of motion. Thus, motor constraints due to spatial compatibility, hand preference and bimanual coordination (but not midline crossing) must be taken into account to understand age differences in grasping a moving object.
Perception and production of object-related grasping in 6-month-olds
In this study, 6-month-olds' perception of an object-related human grasping action was compared with their level of grasping performance using a within-participants design. In the action perception task, infants were presented with the video of an actor's grasping movement toward an occluded target object. Subsequently, an expected and an unexpected final state of this grasping movement were presented simultaneously, and infants' looking times were measured. In the action production task, infants were presented with three graspable objects. Infants' grasping behavior was coded to be either palmar or thumb-opposite grasping. Results indicate that infants who were already able to perform a thumb-opposite grasp differentiated between the two final states in the action perception task by looking longer toward the unexpected final state. In contrast, infants who showed only palmar grasps looked equally long toward both final states. This finding supports the assumption that action perception and action control are already closely related in infants as young as 6 months.
Seeing and touching: The role of sensory-motor experience on the development of infant reaching
Infant Behavior and Development, 2009
Researchers agree that infants must learn from prior sensory-motor experiences to plan, perform, and fine-tune their actions to the environment. Yet, little is known about the actual influences of these experiences on the development of infants' perception and action. This study investigated how repeated experiences of seeing, reaching for, touching, grasping, and manipulating objects of same sizes and textures contributed to the refinement of subsequent object-oriented motor responses in 6-9-month old infants. In addition, to understand whether infants relied on vision, touch, or both to tailor their motor response to objects, we analyzed the reach-to-grasp sequences. Results show that the youngest infants did not benefit from the repeated experiences. Seemingly stereotypical motor responses appeared to interfere with the process of perceptual-motor mapping. The older infants relied more effectively on prior experience, on touch initially and then vision, to match their motor responses to objects. Consistent with a dynamic systems approach, we interpret the observed developmental progression as a change in tensions between perception and action.
Palmar Grasp Reflex in Human Newborns
Pediatrics & Therapeutics, 2017
Purpose: To review palmar grasp reflex in human infants regarding psychomotor development. Method: "Palmar grasp reflex" and "grasping reflex" were searched in scientific journals published between 2000 and 2016. Two groups were identified in newborns up to six months: (1) Palmar grasp reflex was studied as part of instruments of neuropsychomotor evaluation. (2) Palmar grasp reflex was taken as a dependent or independent variable. Results: Eighteen articles were selected. Four were excluded because of inappropriate methods. Concerning the fourteen remaining, teen were included in group 1 (A) and four in group 2 (B). Conclusions: Palmar grasp reflex may be part of different instruments used to evaluate clinical and developmental studies. It may be easily detected without a necessary environment. Its intensity may be used as an index for acquisition of motor skills and lateral differences may be associated with hand preference in adults.
Toy-oriented changes during early arm movements: Hand kinematics
Infant Behavior and Development, 2006
In a recent cross-sectional study, we found that young infants changed their spontaneous arm movements in the presence of a toy, termed 'toy-oriented changes', in systematic ways beginning many weeks before their first consistent reaches [Bhat, A. N., Heathcock, J. H., & Galloway, J. C. (2005). Toy-oriented changes in hand and joint kinematics during the emergence of purposeful reaching. Infant Behavior and Development, 28(4), 445-465]. The purpose of the present study was to test specific hypotheses regarding toy-oriented changes in a longitudinal design. Methods: Thirteen infants were observed every other week from 8 weeks of age up to the onset of reaching. At each session, hand and joint motions were observed with and without a toy present using a high-speed motion capture system. This paper focuses on the toy-oriented changes in hand variables. Results: As predicted, infants displayed a meaningful pattern of toy-oriented changes, which systematically changed as infants approached the first week of reaching. During the Early phase (8-10 weeks before reaching), infants scaled down their movement length and speed in the presence of a toy. During the Mid phase (4-6 weeks before reaching), infants scaled up movement number and speed, increased movement smoothness, and decreased their hand-toy distance in the presence of a toy. During the Late phase (within 2 weeks of reaching), infants continued to change their hand's position to get closer to the toy and began contacting it. Interestingly, movement number and smoothness displayed similar developmental patterns, where movement length and speed displayed similar patterns. Conclusion: Toy-oriented adaptation of arm movements emerges in the first months of life and forms a complex, yet tractable continuum with purposeful reaching. These results provide a foundation to test more specific hypotheses of hand and joint coordination in both typically developing infants and those infants born at risk for coordination impairments.