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.