Segmental Trunk Control in Sitting Between Full-Term and Preterm Infants Raised in the Orphanage Setting

<b>Background</b>: Postural control is vital for independent sitting in infants. Those in orphanages face environmental limitations and biological factors that affect trunk control. This study aimed to compare segmental trunk control between full-term and preterm/low-birth-weight infants and examine the correlations with daily activities. <b>Methods</b>: Thirty-three infants (16 full-term, 17 preterm/low birth weight) were assessed using the Segmental Assessment of Trunk Control (SATCo), and 27 were observed with the Daily Activity of Infant Scale (DAIS) over three weekdays and two weekends. <b>Results</b>: A slight significant difference (<i>p</i> < 0.05) in SATCo scores was found, with full-term infants scoring higher. Results found that both prenatal exposure and environmental factors could influence trunk control. A significant correlation (r_s = 0.771, <i>p</i> < 0.001) between trunk control and daily activities underscores the importance of upright and antigravity activities for postural development. A small-to-medium effect size suggested limited practical significance due to being conducted in a single orphanage with a homogeneous sample. <b>Conclusions</b>: The findings emphasize enhancing the orphanage environment and child-rearing practices to support trunk control development through upright posture, movement exploration, and high-quality caregiver interactions.