Shifting of the body center of gravity in low-risk preterm infants: A video-pedoscope study.

Aim: To evaluate whether there is any developmental course of the shifting of the center of gravity (COG) in healthy preterm infants.

Methods: Eleven healthy preterm infants were assessed on a computerized pedoscope from early preterm to term age. Data from the pedoscope and the videorecorder were analyzed with a special software for the assessment of the COG shifting. Infants were placed on the pedoscope in supine position for 5 min. We scored the positions of the COG during its shifting, the body parts most frequently involved in its shifting and the shifting' amplitude at each epoch. We scored the frequency of the COG shifting in head, trunk and bottom, its direction and amplitude using a semi-quantitative scale.

Results: A developmental course of the COG shifting from preterm throughout post-term ages was demonstrated, with COG position displaced from head to bottom. The shifting amplitude decreased with increasing age. Lateral shifting were never observed.

Interpretation: The developmental course of the COG shifting suggests the maturation of postural behaviour in healthy preterm infants. The displacement of the COG from head to bottom and the reduced amplitude of the COG shifting from preterm to post-term age indicates a more stable body position.