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Electromyographic analysis of muscle activation during pull-up variations
James A Dickie1, James A Faulkner2, Matthew J Barnes1
1School of Sport and Exercise, Massey University, Wellington, New Zealand.
Summary
This study found that while overall muscle activation during pull-up variations is similar, the pronated grip significantly increases middle trapezius activation. Differences in muscle activation also occur between the concentric and eccentric phases of the exercise.
Area of Science:
- Exercise Physiology
- Biomechanics
- Sports Science
Background:
- Pull-up variations are common strength training exercises.
- Understanding muscle activation patterns is crucial for optimizing training and preventing injury.
- Previous research has explored EMG during pull-ups, but direct comparisons across grip types with detailed muscle analysis are ongoing.
Purpose of the Study:
- To compare peak muscle activation (EMGPEAK) and average rectified variable muscle activation (EMGARV) across different pull-up grips: supinated, pronated, neutral, and rope.
- To identify specific muscle activation differences in the shoulder-arm-forearm complex during these variations.
- To analyze differences in muscle activation between the concentric and eccentric phases of pull-up exercises.
Main Methods:
- Surface electromyography (EMG) was used to measure activation in eight shoulder-arm-forearm muscles.
- Nineteen strength-trained males participated, performing pull-up variations.
- Muscle activation was recorded as a percentage of maximum voluntary isometric contraction (%MVIC).
Main Results:
- The pronated grip pull-up showed significantly higher EMGPEAK and EMGARV in the middle trapezius compared to the neutral grip.
- EMGARV for brachioradialis, biceps brachii, and pectoralis major were significantly greater during the concentric phase than the eccentric phase across all variations.
- Overall EMGPEAK and EMGARV for the shoulder-arm-forearm complex were similar across different grip types over a complete repetition.
Conclusions:
- While grip variations in pull-ups do not drastically alter overall muscle activation, the pronated grip specifically enhances middle trapezius engagement.
- Significant differences in muscle activation exist between the concentric (lifting) and eccentric (lowering) phases of pull-ups.
- These findings provide insights into exercise selection for targeting specific muscle groups during pull-up training.
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