Are There Cumulative Changes in Lumbar Spine Passive Stiffness Throughout a Week of Prolonged Seated Work?
Bibliographic record
Abstract
This study assessed daily and weekly changes in spine mechanical properties, specifically range of motion and passive stiffness, in those with and without sitting-induced low back pain to determine if time-dependent changes in mechanical properties were related to pain development in prolonged sitting. Over 1 week, 20 participants performed their seated office work and attended 5 laboratory sessions (Monday morning and evening, Tuesday morning, Friday evening, and the following Monday morning) to measure lumbar spine stiffness in passive flexion. Accelerometers measured seated lumbar flexion-extension each workday. In the morning and evening, participants provided low back pain ratings and performed maximum voluntary flexion. Statistical tests compared over time and between pain statuses (nonpain < 10 of 100 mm). There were increases in maximum flexion from morning to evening (2.0°; P = .003) and decreases in angular breakpoints on Monday evening and Tuesday morning (4.6% and 6.8% of passive flexion; P ≥ .056). Classification of seated spine flexion-extension into the transition and high stiffness zones of the passive curve (ie, moderate-high flexion) revealed that sitting strained the posterior passive tissues, likely contributing to the changes in range of motion and stiffness. Nevertheless, alterations in spine properties did not accumulate throughout the week and were not different by pain status.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.000 | 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 teacher head, 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".