Characteristics of antigravity spontaneous movements in preterm infants up to 3 months of corrected age

Aims We investigated whether spontaneous antigravity limbs movements in very low birth weight preterm infants were insufficient compared to those in term infants. The relationship between the quality of general movements (GMs) and antigravity limbs movements was also examined. Methods Preterm infants with very low birth weight without central nervous system disorders nor severe respiration disorders, and healthy term infants were recruited. The infants were set in a supine position. The distance between both hands and between both feet, and the height of both hands and feet from the floor were recorded at 1–3 corrected months for preterm infants, and at 1–3 months for term infants by a 3D motion capture system. The measurements were adjusted for body proportions. GMs in preterm and term infants were assessed similarly. Results Thirteen preterm and 15 term infants completed the study. In preterm infants, the distance between both hands and between both feet were longer, and the height of both hands and feet were lower than those in term infants in all measurements. In term infants, the height of both hands and feet increased as they developed, but no change was observed in preterm infants. In preterm infants with abnormal GMs, the distance between both hands was longer, and the height of both hands and feet was lower than that in those with normal GMs. There were no such differences between preterm infants with normal GMs and term infants with normal GMs. Conclusion Antigravity limbs movements in preterm infants within the first 3 month of corrected age were insufficient compared with those in term infants. Furthermore, no improvement with development was observed in preterm infants. In addition, preterm infants with abnormal GMs showed worse antigravity limbs movements than preterm and term infants with normal GMs. The preterm infants with normal GMs could behave similar to the full term infants.