Assessing movement quality alongside traditional motor milestones provides a more accurate clinical picture of developmental health in preterm infants than relying on milestone attainment alone. According to a longitudinal study published in Early Human Development, evaluating how an infant moves—rather than just whether they reach a task—allows clinicians to detect subtle motor vulnerabilities that standard tools like the Alberta Infant Motor Scale (AIMS) may overlook.
Why Milestone-Based Assessment Has Limits
Milestones track the completion of a physical task, such as rolling over or sitting, but they often fail to capture the nuance of movement. Research led by C.H. Hsieh indicates that infants may successfully reach a milestone while demonstrating reduced fluency, adaptability, or variation in their motion. This gap between “attainment” and “quality” can mask early signs of neurological or developmental challenges.
While the AIMS tool remains a gold standard for measuring gross motor development, the 2026 study suggests it is most effective when paired with the Infant Motor Profile (IMP). By using both, care teams can identify infants who meet age-appropriate benchmarks but lack the motor efficiency required for more complex future development.
At 12 months, researchers observed a negative correlation between IMP scores and AIMS scores. This suggests that as infants reach specific developmental transition points, high milestone scores don’t always align with optimal movement quality, highlighting the need for a multifaceted assessment approach.
How Gestational Age Affects Motor Trajectories
The study found that gestational age at birth significantly influences long-term motor outcomes. Extremely to very preterm infants consistently demonstrated lower scores across total IMP metrics, adaptability, and fluency compared to moderate to late preterm infants.
Data from the cohort of 90 infants showed that by 18 months corrected age, these differences became more pronounced. While moderate to late preterm infants often caught up in milestone attainment, those born at lower gestational ages continued to show qualitative differences in movement. This underscores the necessity for clinicians to tailor follow-up intensity based on the severity of preterm birth rather than using a one-size-fits-all monitoring schedule.
Future Trends in Neonatal Motor Surveillance
The shift toward qualitative assessment marks a change in how pediatric care teams manage high-risk infants. Future clinical protocols are expected to integrate digital movement analysis to provide more objective data on “how” an infant moves, moving beyond the subjective nature of traditional observation.
Clinicians are increasingly adopting longitudinal tracking that spans from early infancy through 18 months or beyond. This continuity allows for the identification of “subtle motor dysfunction,” a category of impairment that might otherwise go undiagnosed until a child reaches school age and faces more complex physical or academic demands.
Pro Tip for Caregivers and Clinicians
Don’t wait for a missed milestone to raise concerns. If an infant displays “stiff” movements, lacks variety in play, or seems to struggle with transitions between positions, request a qualitative motor assessment. Early intervention, guided by both milestone tracking and quality observation, is linked to better long-term functional outcomes.
Frequently Asked Questions
What is the difference between motor milestones and movement quality?
Motor milestones track whether a child can perform a specific task (like standing). Movement quality assesses the fluidity, adaptability, and efficiency of the motion used to perform that task.
At what age is this assessment most critical?
The study highlights that assessment at 8, 12, and 18 months corrected age is vital for identifying developmental trends in preterm infants.
Does a high milestone score mean an infant is developing perfectly?
Not necessarily. An infant may reach a milestone but show reduced quality in their movement, which can be an early indicator of subtle motor vulnerabilities.
Have questions about developmental surveillance or want to learn more about neonatal care standards? Subscribe to our weekly newsletter for the latest clinical updates or join the conversation in the comments below.
