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Myoelectric activity during electromagnetic resistance alone and in combination with variable resistance or eccentric
Hugo Zambrano1, Xavier Torres1, Max Coleman1
1Department of Exercise Science and Recreation, CUNY Lehman College, Bronx, NY, USA.
Scientific Reports
|May 22, 2023
Summary
This study compared electromagnetic resistance devices to traditional dumbbells for elbow flexion exercises. While electromagnetic devices showed slightly higher muscle activation in the anterior deltoid, overall differences were minimal and likely not practically significant for resistance training.
Area of Science:
- Biomechanics
- Exercise Physiology
- Human Movement Science
Background:
- Understanding muscle activation patterns is crucial for optimizing resistance training programs.
- Various resistance modalities exist, each with unique force-velocity characteristics.
- Comparing novel electromagnetic resistance devices to traditional methods is essential for practical application.
Purpose of the Study:
- To compare the myoelectric activity of elbow flexor muscles during resistance exercise using electromagnetic resistance versus traditional dynamic constant external resistance.
- To investigate the effects of variable resistance and eccentric overload settings on muscle activation.
- To determine the practical significance of observed differences in muscle activation.
Main Methods:
- A within-participant randomized cross-over design was used with 16 resistance-trained individuals.
- Participants performed elbow flexion using dumbbells (DB), an electromagnetic device (ELECTRO), variable resistance (VR), and eccentric overload (EO) at a 10-repetition maximum.
- Surface electromyography (sEMG) of the biceps brachii, brachioradialis, and anterior deltoid was recorded and synchronized with motion capture.
Main Results:
- The anterior deltoid exhibited greater concentric sEMG amplitude (7-10%) with EO, ELECTRO, and VR compared to DB.
- Biceps brachii concentric sEMG amplitude was similar across all conditions.
- Dumbbell exercise showed greater eccentric brachioradialis sEMG amplitude compared to the electromagnetic device, though differences were modest (<5%).
Conclusions:
- Electromagnetic resistance devices may offer slight advantages in anterior deltoid activation compared to dumbbells.
- Observed differences in muscle activation between electromagnetic devices and dumbbells were generally modest (<10%) and likely of minimal practical significance.
- Further research could explore long-term training adaptations with different resistance modalities.
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