Posture and movement in healthy preterm infants in supine position in and outside the nest

To evaluate whether lying in a nest affects the posture and spontaneous movements of healthy preterm infants.

10 healthy preterm infants underwent serial video recording in the supine position, when lying in a nest and outside it, at three ages: 30-33 weeks postmenstrual age (PMA) (early preterm), 34-36 weeks PMA (late preterm) and 37-40 weeks PMA (term). The nest was shell-shaped, made by putting two rolled blankets in a form of an oval. Posture was assessed both before and after general movements by scoring the predominant postural pattern. Movements towards and across the midline, elegant wrist movements, abrupt hand and/or limb movements, rolling to side, and frozen postures of the arms and legs were assessed during four general movements. All data relating to motor and postural items were normalised into frequencies of events per minute because the general movements varied in duration.

When lying in the nest, the infants more often displayed a flexed posture with shoulder adduction and elbow, and hip and knee flexion, and the head was frequently in the midline. The nest was also associated with an increase in elegant wrist movements and movements towards and across the midline and a reduction in abrupt movements and frozen postures of the limbs. The nest did not affect the occurrence of asymmetrical tonic neck posture.

A nest promotes a flexed posture of the limbs with adduction of shoulders, facilitates elegant wrist movements and movements towards and across the midline and reduces abrupt movements and frozen postures of the arms and legs.