Cervical Muscle Response to Whiplash-Type Right Lateral Impacts
Bibliographic record
Abstract
STUDY DESIGN: Nine healthy volunteers were subjected to right lateral impacts of 4.9, 8.8, 10.8, and 13.7 m/sec acceleration at two levels of expectation: expected and unexpected. OBJECTIVES: To determine the response of the cervical muscles to increasing low-velocity right lateral impacts and compare the quantitative effects of expected and unexpected impact. SUMMARY OF BACKGROUND DATA: The literature contains little information on the etiology of whiplash injuries. In particular, in vivo studies of the cervical muscular response and head-neck kinematics to lateral impacts are rare. A previous study of left lateral impacts suggests that the burden of impact is borne primarily by the muscles contralateral to the side of impact. METHODS: Bilateral electromyograms of the sternocleidomastoids, trapezii, and splenii capitis were recorded. Triaxial accelerometers recorded the acceleration of the chair, torso at the shoulder level, and head of the participant. RESULTS: At an acceleration of 13.7 m/sec2, both sternocleidomastoids, both trapezii, and the right splenius capitis generated on average around 40% or less of their maximal voluntary contraction electromyogram in both the expected and unexpected impact conditions. The left splenius capitis (i.e., contralateral to the right lateral impact), however, generated 84% of its maximal voluntary contraction electromyogram (double the response of other muscles). Electromyographic variables were affected significantly by the levels of acceleration (P < 0.01). The time to onset and time to peak electromyogram time for all muscles decreased progressively with increasing levels of acceleration. The kinetic variables and the electromyographic variables regressed significantly on the acceleration (P < 0.01), and the head acceleration was affected significantly by expectation (P < 0.01). In response to right lateral impacts, muscle responses were generally greater, with higher levels of acceleration, and greatest for the splenius capitis muscle contralateral to the side of impact (P < 0.01). CONCLUSIONS: Because the muscular component of the head-neck complex likely plays a central role in the abatement of higher acceleration levels, it may be a primary site of injury in the whiplash phenomenon in lateral collisions, and specifically, the splenius capitis muscle contralateral to the side of impact is most likely to be injured. Being aware of an impact may reduce the degree of head perturbation.
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) | 0.001 | 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 | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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".