Fatigue pattern of trapezius muscle in relation to its functional role
Bibliographic record
Abstract
The trapezius muscle is very vulnerable to pain and fatigue. This study investigates the pattern of trapezius fatigue during an isotonic and isometric contraction. It looks at the relationship between the fatigue pattern and the muscle's functional role. Electromyographic (EMG) signals were recorded simultaneously by surface electrodes from the upper trapezius and middle deltoid muscles from 8 healthy subjects. Two different test positions were maintained until the subjective limit of fatigue. In one test position the role of trapezius was as stabilizing synergist, while in the other its role was a prime mover. The RMS and mean power frequency (MPF) values were calculated for every 1 second of the recorded EMG signals. The results show a much more pronounced MPF shift toward lower frequencies when the trapezius is the prime mover than where it is a stabilizing synergist. RMS values show a significant increase when the trapezius is a stabilizer and show a decrease when it is a prime mover. The results challenge the common belief that the RMS value increase during fatigue process and it is hypothesized that the muscle fatigue pattern is directly related to the functional role of the muscle.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".