Effect of training at different body positions on proximal and distal reaching adjustments at the onset of goal-directed reaching: a controlled clinical trial.

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 position 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 position 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.