Effects of the Additional Weight on the Reaching Behavior of Pre Term Infants With Low Birth Weight

Summary

The effects of additional weight on early motor skills of infants have been increasingly studied. During the reaching behavior, the additional weight has been shown benefits in certain kinematic variables in full term and preterm infants. There is a growing interest in the study of populations at risk for motor development, especially considering interventions based on functional activities with the purpose of improving the neuromotor control, functional capacity and muscle strength. The aim of the present study is to investigate the effect of a functional training with additional weight in the reaching behavior of preterm infants with low birth weight and to compare the effects with a full term population. A controlled and randomized trial will be carried out with full term infants of adequate birth weight and preterm infants with low birth weight at 6 months of chronological or corrected age. The participants will be recruited by convenience from the charts of a Public Hospital. Participants will be randomly allocated into four groups: 1) adequate weight placebo group (AWPG); 2) adequate weight intervention group (AWIG); 2) low weight placebo group (LWPG) and 4) low weight intervention group (LWIG). . The assessor will be blinded (no knowledge of groups allocation). All infants will undergo a training program of eight sessions (2x/week; 4 weeks). The AWIG and LWIG will receive the training with an additional weight (characterized by a bracelet with a weight of 20% of the mass of the upper limbs)and the AWPG and LWPG will receive the same training, however, without the additional weight (only the bracelets).. All infants will be assessed in three different moments: 1) Pre-intervention: baseline, before the start of the intervention program; 2) Post-intervention: evaluation performed after the end of the program; and 3) Follow-up: evaluation performed seven days after the post-intervention assessment. The following kinematic dependent variables will be calculated: straightness index, mean velocity and motion units and electromyographic variables: pattern of activation and recruitment of muscle fibers - Biceps brachialis, Triceps brachialis, Deltoid and Pectoralis Major muscles; co-activation between biceps and triceps. The Qualisys Track Manager (QTM) and a wireless surface electromyography with 8-channels will be used. If normality assumptions are met, a mixed 2X2 ANOVA with repeated measures will be applied, in order to verify differences between the intervention programs, considering the dependent variables. Otherwise, non-parametric procedures of the same nature will be adopted. The significance will be set at 5% (P\<0.05).

Conditions

• Preterm Infant
• Infant Development
• Low Birth Weight

Interventions

OTHER

Training with additional weight

The infants will be positioned in a reclined position. A bracelet with an additional weight (20% of the total mass of the upper limb) will be placed on both wrists. The training will happen 2x/week, during 4 weeks (8 sessions). An object will be used to stimulate the reaching behavior, which will be displayed by the examiner (positioned in front of the infant), and presented in the midline at shoulder height, considering the distance from the arm's length of the infant to the height of the wrist. The physiotherapist will draw the attention of the infant to the object, moving it momentarily so that the infant perceives it and reaches it. After reaching, the object will be carefully removed and resubmitted in order to elicit a new movement. The interval between each presentation will be of approximately 5 seconds. At least 10 movements will be stimulated. If the infant does not achieve the 10 reaches within the maximum interval of 15 minutes, the session will be terminated.

OTHER

Training without additional weight

The infants will be positioned in a reclined position. A bracelet without the additional weight will be placed on both wrists. The training will happen 2x/week, during 4 weeks (8 sessions). An object will be used to stimulate the reaching behavior, which will be displayed by the examiner (positioned in front of the infant), and presented in the midline at shoulder height, considering the distance from the arm's length of the infant to the height of the wrist. The physiotherapist will draw the attention of the infant to the object, moving it momentarily so that the infant perceives it and reaches the object. After reaching, the object will be carefully removed (or picked up) and resubmitted in order to elicit a new movement. The interval between each presentation of the object will be of approximately 5 seconds. At least 10 movements will be stimulated. If the infant does not achieve the 10 reaches within the maximum interval of 15 minutes, the session will be terminated.

Sponsors & Collaborators

• University of Brasilia

  lead OTHER

Principal Investigators

• Rodrigo Carregaro, PhD · University of Brasilia

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

6 Months

Max Age

7 Months

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2018-01-12

Primary Completion

2018-09-15

Completion

2018-09-15

Countries

• Brazil

Study Locations