A Pilot Study of the Tongue Pull-Back Exercise for Improving Tongue-Base Retraction and Two Novel Methods to Add Resistance to the Tongue Pull-Back

Abstract

This pilot study investigated the tongue pull-back (TPB) exercise to improve tongue-base retraction as well as two methods to add resistance to the TPB. Surface electromyography (sEMG) to the submental triangle was used as an indication of tongue-base activity on 13 healthy adults during: (1) saliva swallow, (2) 15 mL water swallow, (3) effortful swallow, (4) unassisted TPB, (5) TPB with added resistance by holding the tongue with gauze (finger-resisted TPB), and (6) TPB with the tongue clipped to a spring-loaded tension resistance device (device-resisted TPB). Order of the exercises was randomized. The exercises fell into two groups-weak and intense. Weak exercises included saliva swallow, water swallow, and unassisted TPB (mean sEMG = 19.07 μV, p = .593). Intense exercises included effortful swallow, finger-resisted TPB, and device-resisted TPB (mean sEMG = 36.44 μV, p = .315). Each intense exercise resulted in significantly higher mean sEMG peak amplitude than each weak exercise (p < .05), with one exception; the effortful swallow was not significantly different than the unassisted TPB (p = .171). This study provides preliminary evidence that the unassisted TPB may not be any more helpful for improving tongue-base retraction than normal swallowing. Adding resistance to the TPB by holding the tongue with gauze may be an effective alternative. This study also demonstrates proof-of-concept for creating a device to attach to the tongue and provide tension resistance during the TPB exercise. Further research with a more sophisticated design is needed before such a device can be fully developed and implemented clinically.

Keywords: Deglutition; Deglutition disorders; Dysphagia; Effortful swallow; Electromyography; Strength training; Tongue pull-back; Tongue-base retraction.