Effects of Neuromuscular Electrical Stimulation Synchronized with Chewing Exercises on Bite Force and Masseter Muscle Thickness in Community-Dwelling Older Adults in South Korea: A Randomized Controlled Trial

This study is aimed at investigating the effects of synchronized neuromuscular electrical stimulation (NMES) and chewing exercises on bite force and the masseter muscle thickness in community-dwelling older adults. Material and methods: Forty older adults were enrolled in South Korea and randomly assigned to either an experimental or control group. The experimental group performed chewing exercises using the No-Sick Exerciser equipment synchronized with NMES applied to the bilateral masseter muscles, while the control group performed only chewing exercises. Both groups received interventions for 20 min/day, 5 days/week, for 6 weeks. Bite force was measured using the OCCLUZER device, and masseter muscle thickness was measured using a portable ultrasound. Results: Both groups showed a significant increase in bite force and masseter muscle thickness compared to baseline measurements (p < 0.05). The experimental group showed a significantly higher increase in bite force and masseter muscle thickness than the control group after combined intervention (p < 0.05). Conclusion: This study demonstrates that NMES synchronized with chewing exercises is more efficient in increasing bite force and masseter muscle thickness than chewing exercises alone in community-dwelling older adults.