Effects of the Additional Weight on the Reaching Behavior of Pre Term Infants With Low Birth Weight
Condition: Preterm Infant; Infant Development; Low Birth Weight
MeSH terms: Premature Birth; Body Weight; Birth Weight
Study type: Interventional

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).
    


Intervention name(s): Training with additional weight; Training without additional weight
Intervention type(s): Other; Other
Intervention description(s): 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.; 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.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment