Kinematic Visual Biofeedback Improves Accuracy of Learning a Swallowing Maneuver and Accuracy of Clinician Cues During Training

Abstract

Submental surface electromyography (ssEMG) visual biofeedback is widely used to train swallowing maneuvers. This study compares the effect of ssEMG and videofluoroscopy (VF) visual biofeedback on hyo-laryngeal accuracy when training a swallowing maneuver. Furthermore, it examines the clinician's ability to provide accurate verbal cues during swallowing maneuver training. Thirty healthy adults performed the volitional Laryngeal Vestibule Closure maneuver (vLVC), which involves swallowing and sustaining closure of the laryngeal vestibule for 2 seconds. The study included 2 stages: (1) First accurate demonstration of the vLVC maneuver, followed by (2) Training - 20 vLVC training swallows. Participants were randomized into 3 groups: A) ssEMG biofeedback only; B) VF biofeedback only; and C) Mixed biofeedback (VF for the first accurate demonstration and ssEMG for the training stage). Participants' performances were verbally critiqued or reinforced in real-time while both the clinician and participant were observing the assigned visual biofeedback. Videofluoroscopy and ssEMG were continuously recorded for all participants. Results show that accuracy of both vLVC performance and clinician cues was greater with VF biofeedback than with either ssEMG or Mixed biofeedback (p<0.001). Using ssEMG for providing real-time biofeedback during training could lead to errors while learning and training a swallowing maneuver.

Examination of swallowing maneuver training and transfer of practiced behaviors to laryngeal vestibule kinematics in functional swallowing of healthy adults

“…Participants were only advanced to vLVC training if they performed the vLVC maneuver accurately within 5 attempts. In previous studies, most participants needed less than 5 attempts to achieve the vLVC maneuver (Azola et al, 2016; P. Macrae, Anderson, Taylor-Kamara, et al, 2014).…”

“…The subjects had no history of speech, respiratory, or swallowing problems and data from 51 of these participants were previously reported to test a different hypothesis in Macrae et al (2014) and Azola et al (2016). The local Institutional Review Board (IRB) approved the study and all participants provided written informed consent prior to participation.…”

“…Specifically, we examined transfer when training the volitional laryngeal vestibule closure maneuver (vLVC). The vLVC maneuver begins with a swallow and requires prolonging LVC for at least 2 seconds, thus LVC prolongation is directly targeted with the vLVC maneuver (Azola, Sunday, & Humbert, 2016; P. Macrae, Anderson, Taylor-Kamara, & Humbert, 2014).…”

Kinematic Visual Biofeedback Improves Accuracy of Swallowing Maneuver Training and Accuracy of Clinician Cues During Training in Stroke Patients with Dysphagia

“…Given the barriers in using VF or FEES for therapeutic purposes, submental surface EMG (ssEMG) is commonly employed in dysphagia management as a form of nonkinematic biofeedback because it is widely available, safe, and cost effective . The caveat of ssEMG is that it displays nonkinematic information, meaning that, although it can record and display the activation of muscle groups involved in swallowing, it cannot provide direct visualization of the movements of specific structures essential for airway protection and thus its effectiveness as a visual biofeedback tool in dysphagia management has been questioned . In fact, in a study with concurrent ssEMG and VF, Azola et al showed that when training a swallowing maneuver called the Mendelsohn Maneuver (involves prolonging elevation of the hyoid bone and larynx), changes in ssEMG while performing this maneuver represented less than 40% of the actual kinematics of the hyoid bone or larynx in both healthy adults and individuals poststroke .…”

“…The effects of biofeedback (VF and ssEMG) on the accuracy of swallowing maneuver training was directly tested in healthy adults by Azola et al These results showed that there was a statistically significant increase in performance accuracy when participants had kinematic (VF) feedback throughout training compared with those who had nonkinematic (ssEMG) feedback. It was suggested that poor accuracy during ssEMG training occurred because of missing information about kinematic specificity with ssEMG compared with VF.…”