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Muscle Synergies Reliability in the Power Clean Exercise
Paulo D G Santos1, João R Vaz1,2, Paulo F Correia1
1Neuromuscular Research Lab, Faculty of Human Kinetics, Lisbon University, 1495-751 Cruz Quebrada, Portugal.
Journal of Functional Morphology and Kinesiology
|January 20, 2021
Summary
Muscle synergy analysis reliably tracks muscle coordination during the power clean exercise. This method is consistent across different days and within sessions for novice athletes.
Area of Science:
- Biomechanics
- Motor Control
- Sports Science
Background:
- Muscle synergy extraction is key for understanding muscle coordination in sports.
- Previous reliability assessments have not covered complex athletic tasks.
- The power clean is a complex strength training movement requiring intricate muscle coordination.
Purpose of the Study:
- To evaluate the intra- and inter-day reliability of muscle synergy extraction during the power clean exercise.
- To assess the variability of muscle coordination across sets and days in novice participants.
- To determine if muscle synergy analysis is a reliable method for studying adaptations in muscle strength programs.
Main Methods:
- Electromyography (EMG) data from 16 muscles were collected from 12 novice participants performing power cleans.
- Muscle synergies were extracted using nonnegative matrix factorization (NMF).
- Intra- and inter-day reliability were assessed using variance accounted for (VAF), muscle synergy vectors, and activation coefficients.
Main Results:
- Three muscle synergies explained approximately 90% of the VAF across sets and days.
- High similarity was observed in intra-day VAF, muscle synergy vectors, and activation coefficients.
- Inter-day muscle synergy vectors showed moderate similarity, while temporal activation patterns remained strongly related.
Conclusions:
- Muscle synergies during the power clean are stable across sets and days in novice individuals.
- Nonnegative matrix factorization (NMF) for muscle synergy extraction is a reliable method for studying muscle coordination.
- This approach can be valuable for assessing muscle coordination adaptations in response to strength training programs.
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