The Relationship Between Daily Physical Activity And Pain In Individuals With Knee Osteoarthritis
Bibliographic record
Abstract
Daily physical activity reduces pain and disability from knee osteoarthritis (OA), although the underlying mechanisms are unclear. For instance, bouts of activity might transiently exacerbate pain or may relieve pain via exercise-induced analgesia. PURPOSE: To determine the association between physical activity and pain severity in individuals with knee OA across 7 days. METHODS: Pressure pain threshold (PPT) was measured in 31 participants with knee OA (71.1±10.2 yrs, 19 female) who also completed WOMAC, Arthritis Self-Efficacy Scale, and Brief Fatigue Inventory questionnaires. Following baseline data collection, physical activity was monitored for a week using Actigraph GT3X+ accelerometers and participants diarised their pain, fatigue and medication. Expected associations of weekly physical activity with PPTs and measures of disease status were tested by Pearson’s correlation analyses. Cross-correlation analyses were performed for each participant on the time series of 21 symptom reports across the week and the corresponding morning, afternoon and evening blocks of physical activity. The cross-correlation analyses aimed to detect the relative timing of the strongest association between pain and activity throughout 7 days. RESULTS: Pain, as assessed by questionnaires and PPTs, was negatively correlated with moderate-vigorous physical activity across 7 days (r = -0.586, p < 0.001, r = 0.401, p < 0.05, respectively), whereby people who had less pain were more physically active. The peak of the cross-correlations varied in time and direction across the sample, but was most often positive and lagging, which indicated that pain was exacerbated subsequent to periods of increased physical activity. CONCLUSIONS: Higher levels of physical activity across a week were significantly associated with less pain in individuals with knee OA. However, cross correlations between daily fluctuations of physical activity and pain predominantly indicated that physical activity exacerbated pain rather than relieving symptoms. Therefore, the exercise-induced analgesia previously reported in people with knee OA may not explain the immediate association between pain and bouts of physical activity during everyday living. Rather, chronic adaptations to exercise may reduce the pain in knee OA.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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".