Brachialis Muscle Activity Can Be Measured With Surface Electromyography: A Comparative Study Using Surface and
Shota Date1, Hiroshi Kurumadani1, Yuko Nakashima2
1Laboratory of Analysis and Control of Upper Extremity Function, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Frontiers in Physiology
|January 10, 2022
Summary
Surface electromyography (EMG) can accurately measure brachialis muscle (BR) activity during non-weighted elbow flexion. This method provides a reliable alternative to intramuscular EMG for assessing BR function, independent of biceps brachii activity.
Area of Science:
- Biomechanics
- Neurophysiology
- Kinesiology
Background:
- Intramuscular electromyography (EMG) using fine-wire electrodes is the standard for measuring brachialis muscle (BR) activity.
- The efficacy of surface EMG for assessing BR activity remains uncertain.
Purpose of the Study:
- To compare surface and intramuscular EMG patterns of BR activity during elbow flexion.
- To determine if surface EMG can accurately measure BR activity.
Main Methods:
- Simultaneous surface and intramuscular EMG recordings from BR, biceps brachii long head (BBLH), and short head (BBSH) in six healthy men.
- Muscle locations identified using ultrasonography.
- Tasks included maximum isometric voluntary contractions (MVICs) and isotonic elbow flexion without load.
Main Results:
- Cross-correlation coefficients between surface EMG signals from different muscles were below 0.3.
- Surface and intramuscular EMG patterns for BR activity showed no significant differences during isotonic elbow flexion.
- BR exhibited distinct EMG patterns compared to BBLH and BBSH.
Conclusions:
- Surface EMG accurately assesses brachialis muscle (BR) activity during non-weighted elbow flexion.
- This method is independent of biceps brachii (BBLH and BBSH) activity.
- Surface EMG offers a viable alternative to intramuscular EMG for BR assessment in specific contexts.
