Modulation of EMG-EMG Coherence in a Choice Stepping Task
Ippei Nojima1, Tatsunori Watanabe1,2, Kotaro Saito1
1Department of Physical Therapy, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Frontiers in Human Neuroscience
|March 1, 2018
Summary
This study investigated neurophysiological functions during voluntary stepping in elderly individuals. Higher muscle coherence was observed during simple reaction time tasks, potentially indicating reduced inhibitory activity during complex tasks, which may increase fall risk.
Area of Science:
- Neuroscience
- Motor Control
- Gerontology
Background:
- Falls in the elderly often occur during movement, highlighting the need to understand neurophysiological functions during tasks like voluntary stepping.
- The voluntary step execution task is a key measure for assessing fall risk in community-dwelling older adults.
Purpose of the Study:
- To explore the relationship between electromyography-electromyography (EMG-EMG) coherence and motor performance in simple reaction time (SRT) and choice reaction time (CRT) stepping tasks.
- To investigate the common oscillatory drive to motoneurons during pre-stepping phases in healthy elderly individuals.
Main Methods:
- Electromyography (EMG) was used to analyze EMG-EMG coherence in tibialis anterior (TA) and soleus (SOL) muscles.
- Coherence was measured in the 1000 ms before a visual stimulus in both SRT and CRT tasks in ten healthy elderly participants.
Main Results:
- EMG-EMG coherence in alpha and beta frequency bands was significantly higher in the SRT task compared to the CRT task.
- Beta band coherence in the tibialis anterior muscle showed a positive correlation with performance errors in the CRT task.
Conclusions:
- Higher pre-stepping muscle coherence in SRT tasks suggests greater common oscillatory drive, while lower coherence in CRT tasks may indicate increased inhibitory activity.
- Reduced inhibitory activity, reflected by lower beta band coherence, might be linked to decreased stepping performance and increased fall risk in the elderly.
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