Infants at risk for physical disability may be identified by measures of postural control in supine

Abstract

Background: Early detection of delay or impairment in motor function is important to guide clinical management and inform prognosis during a critical window for the development of motor control in children. The purpose of this study was to investigate the ability of biomechanical measures of early postural control to distinguish infants with future impairment in motor control from their typically developing peers.

Methods: We recorded postural control from infants lying in supine in several conditions. We compared various center of pressure metrics between infants grouped by birth status (preterm and full term) and by future motor outcome (impaired motor control and typical motor control).

Results: One of the seven postural control metrics-path length-was consistently different between groups for both group classifications and for the majority of conditions.

Conclusions: Quantitative measures of early spontaneous infant movement may have promise to distinguish early in life between infants who are at risk for motor impairment or physical disability and those who will demonstrate typical motor control. Our observation that center of pressure path length may be a potential early marker of postural instability and motor control impairment needs further confirmation and further investigation to elucidate the responsible neuromotor mechanisms.

Impact: The key message of this article is that quantitative measures of infant postural control in supine may have promise to distinguish between infants who will demonstrate future motor impairment and those who will demonstrate typical motor control. One of seven postural control metrics-path length-was consistently different between groups. This metric may be an early marker of postural instability in infants at risk for physical disability.

Conflict of interest statement

The authors declare no competing interests.

© 2021. The Author(s).

Figures

Fig. 1. An infant lying supine in the toy gym during the recording of center of pressure (COP).

a Side view of the infant playing with the hanging elephant toy; b aerial view of the infant in the no toy condition; c aerial view of the infant in the orangutan toy condition, designed to encourage bilateral reaching.

Fig. 2. Postural control data processing.

a Schematic of infant lying supine on the instrumented mat. b Example raw data. The Green load cell was wired to be the minimum Y value, and the Yellow load cell as the maximum Y value. The Red load cell relates to X-min., and the Blue as X-max. We hardcode these bounds to be 104 × 104 cm, the measured length along the edges from one load cell to the other. c Representative stabilogram with the raw data calibrated to real-world coordinates and filtered. The data were translated and rotated so the green corner was positioned at (0,0). Actual values for ellipse area and excursions in X and Y are listed.

Fig. 3. Group differences in postural control.

Group data for Path Length (a, b) and Standard Deviation in Y (StdDevY; c, d) for all toy conditions combined and individually. Group comparisons for Full Term vs. Preterm birth are on the left. Group comparisons for future Typical vs. Impaired motor control are on the right. Group differences were considered significant if p < 0.05 and are indicated by asterisk (*) following the condition name. Path length distinguished between groups by birth status and by later motor control for most toy conditions, with the Preterm and Impaired motor control groups having higher path length than the Full Term and Typical motor control groups, respectively. StdDevY distinguished between groups by birth status in the no toy and lion (kicking toy) conditions, with the Preterm group having lower variability in COPy than the Full Term group. Similar differences were observed when grouped by later motor control, but these differences did not reach significance (perhaps due to low statistical power as a result of the small sample size in the Impaired motor control group).