Walking experience affects locomotor exploration in infants born prematurely: a comparative cross-sectional study

This study aimed to investigate the impact of premature birth on the locomotor exploration of infants with up to six months of independent walking experience.

Participated in this study, 16 preterm infants (PT) (32.5 ± 3.59 weeks gestational age) with low birth weight (1.91 ± 0.66 kg) and low- and lower middle income (75%); and 15 full-term infants (FT) (38.93 ± 0.94 weeks gestational age) with normal birth weight (≥ 2.5 kg) and middle- or upper middle income (73.3%). Both groups had similar walking experience and motor development stages and they did not present any physical or mental impairments. Non-object-oriented natural locomotor exploration was measured by recording 20 min in a multidisciplinary laboratory room. Five toys were spread around the room to stimulate upright locomotion, without interaction from the caregiver. Real-time analyses of spontaneous locomotion were coded offline using Datavyu software.

PT and FT infants showed similar locomotor exploration, spending most of their time in standing locomotion (PT: 24.93%, FT: 35.46%) and exhibiting similar locomotor behaviors (i.e. average PT: 623 steps and 2 falls, FT: 995 steps and 3.27 falls). Spearman correlation across all infants showed that greater walking experience (measured in months) was moderately associated with more time in standing locomotion (r = 0.546, p = 0.001), a greater number of bouts (r = 0.543, p = 0.003), and less time in a sitting position (r = -0.636, p = 0.00). Linear regression showed that for infants in the FT group, there was a positive trend between walking experience and time spent in standing locomotion, number of bouts, and number of total steps. The greater the walking experience, the greater the locomotor exploration for FT infants. However, such a relation was not observed in the PT group .

Walking experience can predict developmental changes in the exploratory locomotor behavior of FT infants, but not in PT infants, who exhibit different developmental trends compared to their peers. Opportunities gained with the increase in independent walking experience in the first six months of age do not seem to minimize the subtle impacts associated with being born prematurely on locomotor exploration, which reinforces the necessity for monitoring these infants in early intervention programs, even without motor or mental impairments.