Electromyographic activity of head and trunk muscles in newborns

Abstract Introduction: The electric activity of muscles can be assessed using electromyography to determine their function and help identify possible delays in motor development. Objective: Determine the amplitude of the electromyographic activity of the head and trunk flexor and extensor muscles of term and preterm newborns. Method: This is a longitudinal pilot study where 20 preterm and 20 term newborns admitted to the Prof. Fernando Figueira Institute of Comprehensive Medicine were assessed. All the newborns were evaluated between 24 and 72 hours after delivery, with the premature children assessed a second time when term equivalent age was reached at 40 weeks. Data were recorded using a surface electromyograph and the electrodes were attached to the muscle bellies of the sternocleidomastoid, upper portion of the trapezius, rectus abdominis and erector spinae muscles. Results: Comparison of the electromyographic activity between the preterm newborns showed significantly higher values in all the muscles when the group reached term equivalent age. Additionally, the electromyographic activity of the term group was greater than that obtained by the preterm newborns. Conclusion: With advancing age and maturation of the physiological systems, including the muscle system, preterm newborns tend to exhibit a similar muscle activation behavior to that of the term infants, resulting in better motor development.