123
Motor Control, 2013, 17, 123-144
© 2013 Human Kinetics, Inc.
Official Journal of ISMC
www.MC-Journal.com
ORIGINAL RESEARCH
Motor Control, 2013, 17, 123-144
© 2013 Human Kinetics, Inc.
The authors are with the Department of Physiotherapy, Neuropediatrics Section, Federal University of
São Carlos, 13565-905, São Paulo, Brazil.
Effect of Training at Different Body
Positions on Proximal and Distal Reaching
Adjustments at the Onset of Goal-Directed
Reaching: a Controlled Clinical Trial
Andréa Baraldi Cunha, Daniele A. Soares,
Alyne Montero Ferro, and Eloisa Tudella
The objectives of this study were to verify the influence of a short-duration training
session on proximal and distal adjustments at the onset of goal-directed reaching
and to verify whether these adjustments change in specificity with the body posi-
tion trained. Twenty-four infants aged 3–4 months were assessed in supine and
reclined during pre and posttraining conditions. During the interval (4 min), 8
infants received reaching training in supine, 8 infants received reaching training in
reclined, and 8 infants received no training. The frequencies of reaches, unimanual
reaches and reaches with semiopen and oblique hand increased in the posttraining
condition for all infants except control infants. Infants trained in the reclined posi-
tion increased the frequencies of variables in the reclined position. Infants trained
in the supine position increased the frequencies of variables in both positions. Few
minutes of reaching training are effective to facilitate reaching behavior in infants
at the onset of reaching. The effects are specific to the body position trained. As
the training in supine requires higher torque to initiate reaching movements, it is
more effective to facilitate reaches in both supine and reclined positions.
Keywords: training; physical therapy; motor skills; infant development
When manual reaching is acquired at around 3–5 months of age (Thelen et al.,
1993), infants are able to expand their ability to explore the environment. Soon,
they learn to modify the dynamics of the upper limb to facilitate the approach of
their hand to an object at the midline (Bhat, Lee, & Galloway, 2007) and adjust the
proximal (uni- and bimanual) and distal movements (hand orientation and opening)
of the limb to touch and grasp objects more successfully (Fagard, 2000; Toledo,
Soares, & Tudella, 2011).
Proximal adjustments in early reaches predominantly result from shoulder
movements and are typically bimanual (Fagard, 2000), although head and trunk
support may favor unimanual movements (Carvalho, Gonçalves, & Tudella, 2008a;
Toledo et al., 2011). Distal adjustments are initially performed with the hand hori-