Analysis of facial and inspiratory muscles performance during breastfeeding.

Breastfeeding is a dynamic process in which the infant recruits several muscle groups in his face, head and throat.The objective of this study was to explore the relative role of the submental muscle group, the orbicularis oris and the sternocleidomastoid muscles to breastfeeding process and to the relatively high intra-oral vacuum measured during this process.Electromyography (EMG) measurements were conducted on 11 infants (mean age 1.91 ± 1.0 days, mean weight 3364 ± 328 g) using surface electrodes. The EMG data were filtered with a low pass filter to yield the linear envelopes (IEMG). The maximal and mean value and the area under each linear envelope curve were examined.During active suckling significantly higher activity (P< 0.05) of the submental muscle group were measured compared with the orbicularis oris and sternocleidomastoid muscles (mean ± SE values of the maximal linear envelope were 24.4 ± 1 μV, 9.6 ± 0.6 μV and 14 ± 0.7 μV, respectively).These results confirmed that jaw movements have the primary role during breastfeeding, but also revealed that the inspiratory muscles have a substantial contribution to this process and probably have an important role in the generation of intra oral vacuum measured during breastfeeding.