Meeting Abstract
One of the most significant milestones in a human child’s locomotor development is the ability to walk. However, the time at which infants begin to walk varies greatly with gestation length. Specifically, motor development in preterm human infants is known to be delayed relative to term infants. Here, we test the predictions that 1) motor development will progress more slowly in preterm infants and 2) that preterm infants will require specific adjustments to gait kinematics to promote stability. We collected high-speed video of 8 term and 4 preterm infant pigs walking/running in an enclosed runway using food motivation. Because preterm pigs were born 6 days premature (comparable to 30-32 weeks of human gestation) we subtracted 6 days from their chronological age for comparison to the term pigs. Locomotor performance of infant pigs was assessed by quantifying speed – made dimensionless to compensate for size growth – as well as duty factor and the mean number of supporting limbs during the stride. Preterm pigs significantly increased speed with increasing age (p<0.001), whereas term pigs did not (p>0.05). Controlling for speed, both preterm and term pigs maintained constant duty factors throughout growth (p>0.05), but significantly decreased the mean number of supporting limbs using at older ages (p<0.01). Controlling for speed, preterm pigs always moved with significantly greater duty factors and mean numbers of supporting limbs than term pigs (all p<0.01). As predicted, preterm infants showed protracted motor development and adjusted their gait in ways consistent with the need to maintain greater stability. Our work suggests that infant pigs may be a promising animal model for the study of preterm birth on locomotor development. Supported by NIH RO1-HD-088561 and NEOMED
