How Obesity Affects Jaw Movements: Insights from Electrical Stimulation Research

Welcome to another post from the ORIEMS Fit Research Digest! Each blog brings you fascinating research that sparks curiosity and helps you learn more about the world of science. Today, we explore how electrical stimulation of jaw muscles is affected by obesity, revealing important insights that could help understand masticatory functions.

What This Blog Is About
In this research, scientists studied how electrical stimulation influences jaw movements and muscle activity, focusing on the effects of obesity. This topic is part of our mission to inspire curiosity and help you dive deeper into understanding how our bodies work.

About the Research

• Original Title: Effect of Obesity on Masticatory Muscle Activity and Rhythmic Jaw Movements Evoked by Electrical Stimulation of Different Cortical Masticatory Areas
• Authors: Ruixin Li, Chiho Kato, and colleagues.
• Where and When: Conducted at Tokyo Medical and Dental University, Japan, published in 2023.

Tokyo Medical and Dental University is a highly respected institution known for its focus on advanced research in medical and dental sciences.

Who Funded It?
The research was partially funded by the Japanese Ministry of Education, Culture, Sports, Science, and Technology, ensuring it meets rigorous academic standards.

What Was Studied?
This study examined how obesity affects jaw movements and muscle activity when stimulated electrically. Researchers compared two groups of male Zucker rats—one group genetically prone to obesity and the other lean. They used electrical stimulation to analyze muscle activity and jaw movements.

Key Findings

1. 1. Faster Jaw Opening in Obese Rats

      • Obese rats showed a significantly faster jaw-opening speed during electrical stimulation of the posterior masticatory area (P-area) compared to lean rats.
        • Obese rats (OZR): 67.5 mm/s
        • Lean rats (LZR): 50.8 mm/s
      • This represents a 33% increase in jaw-opening speed in obese rats.

   2. Shorter Jaw-Opening Duration in Obese Rats

      • During P-area stimulation, the jaw-opening phase lasted:
        • Obese rats (OZR): 24.3 milliseconds
        • Lean rats (LZR): 27.9 milliseconds
      • This shows a 13% reduction in jaw-opening duration for obese rats.

   3. Consistent Jaw-Closing Force Despite Faster Speed

      • The peak-to-peak muscle contraction strength of the anterior digastric muscle (used for jaw opening) remained unchanged between obese and lean rats.
        • Muscle strength indicator: No significant difference in electromyographic (EMG) amplitude, meaning that despite their faster movements, obese rats did not lose force.

   4. Coordinated Movement Patterns

      • Obese rats maintained full jaw-opening capacity, demonstrating no reduction in gape size (vertical jaw movement) or lateral movement (side-to-side jaw capacity). This shows that the jaw's structural and functional abilities remained intact.
        • Gape size: No difference between obese and lean rats.
        • Lateral movement: No significant variation in side-to-side motion.

   5. Neuromuscular Changes in Response Time

      • The time it took for jaw muscles to respond to electrical stimulation (onset latency) was shorter in obese rats:
        • Obese rats (OZR): ~5.2 milliseconds
        • Lean rats (LZR): ~6.9 milliseconds
      • This 25% reduction in response time suggests increased nerve conduction velocity in obese rats.

   These specific, data-driven findings highlight how electrical stimulation interacts with muscle activity and coordination, providing a clearer picture of how factors like obesity can influence neuromuscular performance.

Why Is This Important?
Electrical muscle stimulation (EMS) can improve muscle activity and coordination. This study highlights that obesity changes how muscles respond, which could provide insights into creating better tools for muscle stimulation in humans. For instance, EMS devices might help improve muscle function and coordination for individuals with obesity-related issues.

How It Relates to EMS Devices

• This research supports the idea that EMS can influence muscle coordination and movement patterns.
• EMS users might benefit from understanding how factors like weight can affect muscle responses, helping them set realistic goals for muscle training or therapy.

About ORIEMS Fit Research Digest
Our mission is to share exciting research to inspire your journey of self-learning. We simplify complex studies into bite-sized pieces, making science approachable for everyone. We hope this blog inspires you to explore more about the incredible potential of EMS technology and its applications.

Source of Information
You can find the full research here: Link to Study. This source is trustworthy as it comes from a peer-reviewed journal, ensuring the quality and credibility of the data.

Disclaimer
This blog post is for informational purposes only. It is not medical advice. Always consult a healthcare professional before starting any new treatment. Learn more about our disclaimer here.

Relevant Topics to Explore

• Electrical muscle stimulation benefits.
• How muscle function changes with obesity.
• Simple tips for using EMS devices effectively.

Stay curious, and we’ll see you in the next ORIEMS Fit Research Digest post!