Difference Between Male and Female Ice Hockey Players in Muscle Activity, Timing, and Head Kinematics During Sudden Head Perturbations
Bibliographic record
Abstract
This study examined sex differences in head kinematics and neck muscle activity during sudden head perturbations. Sixteen competitive ice hockey players participated. Three muscles were monitored bilaterally using surface electromyography: sternocleidomastoid, scalene, and splenius capitis. Head and thorax kinematics were measured. Head perturbations were induced by the release of a 1.5-kg weight attached to a wire wrapped around an adjustable pulley secured to the participant's head. Perturbations were delivered in 4 directions (flexion, extension, right lateral bend, and left lateral bend). Muscle onset times, muscle activity, and head kinematics were examined during 3 time periods (2 preperturbation and 1 postperturbation). Females had significantly greater head acceleration during left lateral bend (31.4%, P < .05) and flexion (37.9%, P = .01). Females had faster muscle onset times during flexion (females = 51 ± 11 ms; males = 61 ± 10 ms; P = .001) and slower onset times during left lateral bend and extension. Females had greater left/right sternocleidomastoid and scalene activity during extension (P = .01), with no difference in head acceleration. No consistent neuromuscular strategy could explain all directional sex differences. Females had greater muscle activity postperturbation during extension, suggesting a neuromuscular response to counter sudden acceleration, possibly explaining the lack of head acceleration differences.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.004 | 0.001 |
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".