Eloisa Tudella

The development of reaching behavior in low-risk preterm infants

This longitudinal study investigated the development of reaching behavior in the seated position in preterm infants at the ages of 5-7 months by analyzing kinematic variables (straightness and adjustment indexes, movement unit, mean and final velocities). The correlation between kinematic variables and grasping was verified. The participants were nine low-risk preterm infants with no cerebral lesions. Ten fullterm infants served as control. In both groups, kinematic variables remained unchanged over age, except for the adjustment index, which was higher at 6 months in the preterm group. Successful grasping increased in both groups over age and it was shown to be negatively correlated with mean velocity in the preterm infants. At the ages of 6 and 7 months, preterms showed lower mean and final velocities and higher adjustment index when compared with fullterms. The relative constancy in the kinematic variables suggests that, after having explored the action possibilities during the acquisition phase, the infants selected an adaptative pattern to perform the reaching movements. Slower movements and greater adjustments may be functional strategies of preterms to achieve successful grasps.

Description of the motor development of 3–12 month old infants with Down syndrome: The influence of the postural body position

The purpose of the present study was to describe the rate of motor development in infants with Down syndrome in the age range of 3-12 months and identify the difficulties both in performance and acquiring motor skills in prone, supine, sitting and standing positions. Nineteen infants with Down syndrome and 25 healthy full term typical infants were assessed using the Alberta Infant Motor Scale (AIMS) monthly from 3 to 12 months of age. The infants with Down syndrome achieved significant later the level of motor performance of the typical infants. In the supine posture, the performance was significantly lesser for the Down syndrome infants in comparison to the typical infants from the 3rd to 6th month and in the 8th month. In the prone, sitting and standing postures this difference is found for all the months. In conclusion, the sequence of motor development of the Down syndrome is the same as the typical infants. However infants with Down syndrome need more time to acquire skills, mainly antigravitational ones, among them the standing position.

Influência do tamanho e da rigidez dos objetos nos ajustes proximais e distais do alcance de lactentes

BACKGROUND: Studies have identified that object properties lead to adjustments to reaching. However, few have investigated the specific influence of object size and rigidity among young infants. OBJECTIVE: To verify whether four to six-month-old infants make proximal and distal adjustments when reaching for objects of different sizes and rigidity. METHOD: Nine healthy infants were seated on a chair inclined at 50°. Four objects were presented to them: one large rigid (LR), one small rigid (SR), one large malleable (LM) and one small malleable object (SM), each for a one-minute period. A total of 384 reaches were analyzed to verify proximal adjustments (single-hand and two-hand reaching) and distal adjustments (horizontal, vertical and oblique hand orientation; opened, closed and half-open hand), and the success in reaching the objects. RESULTS: The infants exhibited two-hand adjustments for the LR object and single-hand adjustments for the other objects. Oblique orientation was predominant for touching the objects, while vertical orientation was predominant for grasping them, particularly the LR object. Horizontal orientation was not observed for grasping the LR object. At the start of reaching for all objects, the hands were most frequently half-open, while the hands were predominantly open when touching the LR object. Success was greater when reaching for malleable objects (LM, SM) than for rigid objects (LR and SR). CONCLUSION: The young infants studied were capable of planning and adjusting their movements on the basis of their perceptions of the physical properties of the objects, which suggests that perception-action interaction was occurring.

The effect of a short bout of practice on reaching behavior in late preterm infants at the onset of reaching: a randomized controlled trial.

The purpose of this study was to examine the effects of a short bout of practice on reaching behavior in late preterm infants at the onset of goal-directed reaching. The study was designed as a blind, three-arm parallel-group, randomized controlled, clinical trial. Thirty-six late preterm infants were recruited from a maternity hospital and allocated according to computer generated randomization into groups that received reaching practice based on either a blocked schedule, a serial schedule, or no practice. Practice consisted of a 4 min session of induced reaching using a toy in three activities guided by a physical therapist. The activities were elicited in separate blocks for the blocked practice group and in a pre-established order for the serial practice group. The control group stayed in the physical therapists lap but was not stimulated to reach. The infants were assessed 3.3±1.4 days after the onset of goal-directed reaching in three tests: pre-test (immediately before practice), post-test (immediately after practice), and retention test (24 h after post-test). During assessments, the infants were seated in a baby chair and a toy was presented at his/her midline within reaching distance for 2 min. Changes in the number of reaches, proportions of uni/bimanual reaches and kinematic parameters of reaching were main outcome measures. From pre- to post-test, the amount of reaches and bimanual reaches increased in the serial practice group, but the increase was not maintained in the retention test. Kinematic parameters were not affected by practice. Changes in the reaching behavior of late preterm infants can be triggered after the first few minutes of toy-oriented experience based on a serial practice schedule. These changes are not consolidated one day later.

Infants with Down syndrome: Percentage and age for acquisition of gross motor skills

The literature is bereft of information about the age at which infants with Down syndrome (DS) acquire motor skills and the percentage of infants that do so by the age of 12 months. Therefore, it is necessary to identify the difference in age, in relation to typical infants, at which motor skills were acquired and the percentage of infants with DS that acquire them in the first year of life. Infants with DS (N=20) and typical infants (N=25), both aged between 3 and 12 months, were evaluated monthly using the AIMS. In the prone position, a difference of up to 3 months was found for the acquisition of the 3rd to 16th skill. There was a difference in the percentage of infants with DS who acquired the 10th to 21st skill (from 71% to 7%). In the supine position, a difference of up to one month was found from the 3rd to 7th skill; however, 100% were able to perform these skills. In the sitting position, a difference of 1-4 months was found from the 1st to 12th skill, ranging from 69% to 29% from the 9th to 12th. In the upright position, the difference was 2-3 months from the 3rd to 8th skill. Only 13% acquired the 8th skill and no other skill was acquired up to the age of 12 months. The more complex the skills the greater the difference in age between typical infants and those with DS and the lower the percentage of DS individuals who performed the skills in the prone, sitting and upright positions. None of the DS infants were able to stand without support.

The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy.

The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to relate the level of motor impairment in children with cerebral palsy, as classified by to the Gross Motor Function Classification System, to the heart rate variability indices. The heart rate variability was analyzed by linear model in the frequency domain, at low and high frequency bands in normalized units and low and high frequency ratio. The results indicate that children with cerebral palsy present lower heart rate variability indices, indicating sympathovagal imbalance. The decrease of heart rate variability in children with cerebral palsy is related to the motor impairment level.

Effects of treadmill inclination on the gait of children with Down syndrome

The goal of this study was to analyze the effects of upward treadmill inclination on the gait of children with Down syndrome (DS). Sixteen children with a mean age 8.43 ± 2.25 years, classified at level I of the Gross Motor Function Classification System (GMFCS) and able to walk without personal assistance and/or assistive devices/orthosis were evaluated. Spatial-temporal variables were observed as well as the angular variation of hip, knee and ankle in the sagittal plane, while children walked on the treadmill carried out on 0% and 10% upward inclination. The results showed that children with DS presented changes in spatio-temporal variables (reduced cadence and increased cycle time and swing time) and in angular variables (increased hip, knee and ankle angles at initial contact; increased maximum hip flexion and maximum stance dorsiflexion; and reduced plantarflexion at pre-swing). Treadmill inclination seemed to act positively on the angular and spatio-temporal characteristics of gait in children with DS, demonstrating a possible benefit from the use of this type of surface in the gait rehabilitation of this population.

Proximal and distal adjustments of reaching behavior in preterm infants.

Abstract The authors aimed to investigate proximal and distal adjustments of reaching behavior and grasping in 5-, 6-, and 7-month-old preterm infants. Nine low-risk preterm and 10 full-term infants participated. Both groups showed the predominance of unimanual reaching, an age-related increase in the frequency of vertical-oriented and open hand movement, and also an increase in successful grasping from 6 to 7 months. The frequency of open hand was higher in the preterm group at 6 months. Intrinsic restrictions imposed by prematurity did not seem to have impaired reaching performance of preterm infants throughout the months of age.

Development of exploratory behavior in late preterm infants

Exploratory behaviors of 9 late preterm infants and 10 full-term infants were evaluated longitudinally at 5, 6 and 7 months of age. Eight exploratory behaviors were coded. The preterm infants mouthed the object less and had delayed gains in Waving compared to the full-term infants.

Influence of specific training on spatio-temporal parameters at the onset of goal-directed reaching in infants: a controlled trial

BACKGROUND There is evidence that long-term experience can promote functional changes in infants. However, much remains unknown about how a short-term experience affects performance of a task. OBJECTIVE This study aims to investigate the influence of a single training session at the onset of goal-directed reaching on the spatio-temporal parameters of reaching and whether there are differences in the effects of training across different reaching positions. METHOD Thirty-three infants were divided into three groups: 1) a control group; 2) a group that was reach trained in a reclined position; and 3) a group trained in the supine position. The infants were submitted to two assessments (pre- and post-training) in two testing positions (supine and reclined at 45°). RESULTS The short-duration training sessions were effective in promoting shorter reaches in the specific position in which the training was conducted. Training in the reclined position was associated with shorter and faster reaches upon assessment in the reclined position. CONCLUSIONS A few minutes of reach training are effective in facilitating reaching behavior in infants at the onset of reaching. The improvements in reaching were specific to the position in which the infants were trained.