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Updated: Dec 29, 2025
Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
Influence of head position and head position-change on body posture in pre-term infants (A.T.N.R.)
J S Vles1, R van Oostenbrugge, H Kingma
1Department of Neurology, University Hospital of Maastricht, University of Limburg, The Netherlands.
Insights
Head turning in preterm infants influences leg posture, causing one leg to extend and the other to flex. This effect is temporary, lasting only 20 seconds after the head movement.
Area of Science:
- Neonatal development
- Infant biomechanics
- Developmental pediatrics
Background:
- Limited consensus exists on head position's influence on preterm infant body posture.
- Understanding these postural changes is crucial for assessing developmental milestones.
Purpose of the Study:
- To analyze limb flexion/extension patterns in relation to head position changes in healthy preterm infants.
- To determine if head turning elicits consistent postural responses in preterm infants.
Main Methods:
- Longitudinal study of 15 healthy preterm infants from 32 to 36 weeks conceptional age.
- Weekly assessments of limb flexion/extension patterns during spontaneous head turns.
- Observation of postural changes over 3-hour sessions.
Main Results:
- A significant leg flexion/extension pattern was observed: head turning induced extension of the chin-side leg and flexion of the other leg.
- This pattern was consistent across ages and infant states, persisting throughout observation but resolving within 20 seconds.
- No significant postural patterns were noted for other limbs or combinations.
Conclusions:
- Head position changes in preterm infants elicit a specific, transient leg postural response.
- The Asymmetric Tonic Neck Reflex was infrequently observed, suggesting it's not the primary mechanism for this response.
Abstract:
Although body posture in pre-term infants is generally studied to describe developmental aspects, no consensus exists in literature about the influence of head position and head position change upon body posture in pre-term infants. In a weekly assessed longitudinal study of 15 healthy pre-term infants we extensively observed and analysed the flexion and extension patterns of the limbs in relation to a "spontaneous" head position turning from 32 to 36 weeks of conceptional age. A significant flexion/extension pattern was only observed with respect to the leg: turning of the head induced extension of the chin leg and flexion of the other leg. This pattern persisted during the total 3 hours observation sessions, occurred at every age and in all states, but rapidly disappeared within maximal 20 seconds after the head-turning. No consequent significant pattern was observed with respect to the other limbs or the various other combinations of limb posture changes analysed. An Asymmetric Tonic Neck Reflex was seen after only 3 percent of the head position changes.
