Posture and spontaneous motility in fullterm infants.

Posture and spontaneous motor patterns during the first days of life were studied in ten healthy fullterm infants by direct observation and videorecording. The aim of the study was to provide a description of motor and postural characteristics of normal newborns. The infants were recorded for 1 h on their first and fourth day of life, when unstimulated in an incubator. Incidence and duration of the different body postures and motor patterns were scored during the replay of the videorecordings. The preference for the fully flexed posture of arms and legs described in the literature could not be confirmed. There was a large intra- and inter-individual variability in the postural repertoire. No particular posture, characteristic for each behavioural state, existed. Similar postures rarely occurred in the same infant on the first and fourth day. Extended postures more often occurred on the fourth day. Spontaneous motility consisted of several distinct movement patterns, the occurrence of which in states 1 and 2 was computed for day 1 and day 4. Motor patterns were differently related to the states. No differences were noted in the motor activity between the first and fourth days. Large inter-individual differences, but an intra-individual consistency, were found in the rates of specific motor patterns: infants who showed a low or high rate of particular movements on day 1 maintained the same characteristic on day 4. There was no overall low or high motor activity.