The Effect of Lingual Resistance Training Interventions on Adult Swallow Function: A Systematic Review

Lingual resistance training has been proposed as an intervention to improve decreased tongue pressure strength and endurance in patients with dysphagia. However, little is known about the impact of lingual resistance training on swallow physiology. This systematic review scrutinizes the available evidence regarding the effects of lingual resistance training on swallowing function in studies using Videofluoroscopic Swallowing Studies (VFSS) with adults. Seven articles met the inclusion criteria and underwent detailed review for study quality, data extraction, and planned meta-analysis. Included studies applied this intervention to a stroke and brain injury patient populations or to healthy participants, applied different training protocols, and used a number of outcome measures, making it difficult to generalize results. Lingual resistance training protocols included anterior and posterior tongue strengthening, accuracy training, and effortful press against hard palate with varying treatment durations. VFSS protocols typically included a thin barium stimulus along with one other consistency to evaluate the effects of the intervention. Swallowing measures included swallow safety, efficiency, and temporal measures. Temporal measures significantly improved in one study, while safety improvements showed mixed results across studies. Reported improvements in swallowing efficiency were limited to reductions in thin liquid barium residue in two studies. Overall, the evidence regarding the impact of lingual resistance training for dysphagia is mixed. Meta-analysis was not possible due to differences in methods and outcome measurements across studies. Reporting all aspects of training and details regarding VFSS protocols is crucial for the reproducibility of these interventions. Future investigations should focus on completing robust analyses of swallowing kinematics and function following tongue pressure training to determine efficacy for swallowing function.