Corticospinal and Spinal Excitability to the Biceps and Triceps Brachii is Modulated Differently between Forward and Backward Arm Cycling
Bibliographic record
Abstract
The purpose of this study was to evaluate supraspinal and spinal excitability to the biceps and triceps brachii when comparing forward (FWD) and backward (BWD) arm cycling. Supraspinal and spinal excitability were assessed non‐invasively using transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) and transmastoid electrical stimulation (TMES) to elicit cervicomedullary evoked potentials (CMEPs), respectively. MEPs and CMEPs were recorded from the biceps and triceps brachii during FWD and BWD arm cycling at two positions, the 6 and 12 o'clock position. The 6 o'clock position corresponded to mid elbow flexion and extension during FWD and BWD cycling, respectively, while the 12 o'clock position corresponded to mid elbow extension and flexion during FWD and BWD cycling, respectively. Participants completed four arm cycling trials, two FWD and two BWD, at 60 rpm and 25 W. During the flexion phase MEP ( p = .001) and CMEP ( p = .001) amplitudes of the biceps brachii were higher during FWD cycling. However, during the extension phase MEP ( p = .006) and CMEP ( p = .003) amplitudes were higher during BWD cycling. For the triceps brachii MEP amplitudes were higher during FWD cycling compared to BWD ( p = .027) regardless of the functional phase (flexion vs. extension) of the movement cycle. However, spinal excitability to the triceps brachii was dependent on the functional phase of the movement cycle. During the flexion phase CMEPs of the triceps brachii were higher during FWD cycling compared to BWD ( p = .032), but during the extension phase CMEPs were higher during BWD cycling compared to FWD ( p = .001). This data suggests that the modulation of CSE and spinal excitability to the biceps brachii is dependent on the functional phase of the movement cycle and on the cycling direction. Also, spinal excitability but not CSE to the triceps brachii is dependent on the functional phase of the movement cycle when comparing FWD and BWD cycling. Support or Funding Information NSERC Discovery Grant awarded to K.E. Power This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
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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".