Surface Electromyography Assessment of Muscle Activity in Preterm Infants With Feeding Disorders Following Premature Infant Oral Motor Intervention: A Prospective Pilot Study.

BACKGROUND

Premature infants frequently experience feeding difficulties because of immature oral-motor coordination. The Premature Infant Oral Motor Intervention (PIOMI) has been shown to improve feeding skills, but objective evidence regarding its effects on orofacial muscle activity remains limited.

PURPOSE: To evaluate the effects of PIOMI on orofacial muscle activity and feeding outcomes in premature infants with feeding disorders.

METHODS

This pilot study was conducted in Neonatal Intensive Care Units in Mazandaran, Iran. Ten premature infants (gestational age 29-36 weeks; mean 32.4 ± 2.1; birth weight 1706 ± 476 g) received daily PIOMI sessions for 7 days by a trained speech therapist. Orofacial muscle activity (masseter, zygomatic, and orbicularis oris) was measured using surface electromyography (sEMG) at rest and during non-nutritive sucking. Oral-motor skills were assessed with the Preterm Infant Oral Feeding Readiness Assessment Scale (POFRAS), and milk intake volume was recorded.

RESULTS

All infants completed the intervention in March 2025 without adverse events. The sEMG amplitudes increased significantly for the masseter (20.96-52.79 μV, P < .001), zygomatic (29.07-69.56 μV, P < .001), and orbicularis oris (20.97-73.36 μV, P < .001). POFRAS scores improved from 12.10 ± 3.38 to 20.70 ± 5.60 (P < .001), and milk intake from 40.00 ± 6.66 mL to 45.00 ± 18.40 mL (P < .001).

IMPLICATIONS FOR PRACTICE AND RESEARCH: PIOMI enhances orofacial muscle activity and feeding skills in premature infants. These findings support sEMG as an objective evaluation tool and provide preliminary evidence for larger clinical trials.