Surface Electromyographic Activity of Submental Muscles During Swallow of Masticated Bolus Across Age and Gender

Abstract

Background/Objective: Previous researchers have documented changes in sub mental muscle activity during single liquid swallows across demographic and bolus characteristics. As aging increases fatigue and alters muscle properties, we hypothesized that sub mental muscle performance during swallows of masticated boluses in young and older individuals would be different. Methods: The potentials were recorded from sub mental muscles of forty seven healthy individuals of 18-40 years and 40-60 years. Each sEMG trace associated with swallow was analysed for its amplitude and temporal measures and were subjected to statistical comparisons across gender, age and bolus volumes. Results: The results revealed that the measures of sEMG were not significantly different across gender or bolus volume, but was different across the two age groups. The peak sEMG amplitude was lesser in older individuals for ½ cookie and 1 cookie bolus indicating age-associated changes in sub mental muscle performance. The relaxation rate of sub mental muscles was slower for large bolus swallows in older individuals compared to younger, probably as to prevent secondary aspiration. Conclusions: These findings suggest that sub mental muscle performance changes before 60 years of age with weaker peak contraction without altering the durational aspects of swallow. These subtle changes, if picked up could help understand age-associated decline in swallowing efficiency in typically aging population.