The Application of Surface Electromyographic Biofeedback in Dysphagia Rehabilitation in Acute Stroke

Student thesis: Doctoral ThesisDoctor of Philosophy


Dysphagia is common after stroke and leads to worse outcome. Previous studies
have claimed benefits of biofeedback with surface Electromyography (sEMG) in
swallowing therapy, but due to methodological weaknesses the findings are difficult to interpret. Feasibility studies are lacking regarding its application in therapy.

Current approaches in dysphagia therapy in stroke were examined through a nationwide survey of Speech and Language Therapists (n=138). Variability in practice and poor uptake of existing guidelines and evidence was revealed, highlighting the need for more research and measures to promote consistency and best practice. The commonly used Kay Digital Swallow Workstation was validated against a reference sEMG system and found to provide appropriate measurement of amplitude of muscle activity, justifying its use in swallow biofeedback and in subsequent studies of this thesis.

The reliability of submental swallowing sEMG amplitudes was found to be poor in 14 stroke and 85 healthy participants, confirming the need to normalise data for fair comparison. Normalising data to the mean normal swallow amplitude significantly reduced variability, supporting its use as a normalisation reference measure.

No age-related changes were found in the variability of muscle activity for swallowing or the ability to increase submental activity for the effortful swallow (ES) in 85 healthy participants. Dysphagic acute stroke patients and healthy controls significantly increased submental muscle activity for the ES compared to the normal swallow (NS) and for the ES with sEMG biofeedback than without. A questionnaire found that participants considered the ES was significantly easier with sEMG biofeedback. Limited inter-rater agreement was found between SLTs’ clinical assessment of the ES and there was no relationship between clinical rating and sEMG measurements. A pilot Randomised Controlled Trial (RCT) investigating the effect of the ES with and without sEMG biofeedback in dysphagic acute stroke patients (n=10) demonstrated feasibility of the study protocol.

These studies confirm the potential benefit of incorporating sEMG biofeedback with the ES for dysphagic acute stroke patients and justify a subsequent RCT to determine its effect on outcome.
Date of Award2014
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorDianne Newham (Supervisor) & Christina Smith (Supervisor)

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