Effects of two types of tongue strengthening exercises in young normals. Folia Phoniatr Logopedica 2003;55:199–205. Shaker R, Kern M, Bardan E, et al. Augmentation of deglutitive upper esophageal sphincter opening in the elderly by exercise. Am J Physiol 1997;272:G1518–G1522. | PubMed...