EFFECT OF NECK AND HEAD POSITIONING ON TRANSCRANIAL MAGNETIC STIMULATION MOTOR-EVOKED POTENTIALS
Bibliographic record
Abstract
The purpose of this project was to evaluate the effects of head and neck positioning on the amplitude of motor evoked potentials (MEP). Six healty male subjects with no known neurological impairment or pathology of the spinal column participated in this preliminary study. MEP elicited from transcranial magnetic stimulation at the vertex were measured at the thenar eminence muscles using standard surface EMG recording techniques for three trials per condition. For all conditions, subjects lied prone on a chiropractice table. Experimental conditions were: flexion (FLEX), extension (EXT), clockwise (CWR) and counter clockwise (CCR) rotations of the cervical column. The neutral position (head and neck resting in line with the body) was used as the reference position. The intensity of the stimulation, for a given subject, was adjusted as to elicit an optimal MEP in the reference position, and remained the same for all conditions. Mean MEP peak-to-peak amplitude was expressed as a percent of the reference position response. Results reveal the following mean MEP: 90% for the FLEX condition, 87% for EXT, 111% for CCR, and 87% for CWR. The MEP modulation was highly variable between subjects. The MEP modulation measured in this project is consistent with the H-reflex modulation associated with static positioning. In conclusion, although no consistent modulation pattern was observed among subjects, data indicate that the position of the head and neck has an effect on central motor output modulation. Our results illustrate the need for baseline data before studying the effects of intervention techniques, such as a chiropractic adjustment. This project represents only one step of a research program and, hence, more research is being conducted on a larger sample of subjects, in order to determine the nature of the changes measured in this study and increase the consistency of the findings.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.003 | 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".