Quadriceps activation failure as a moderator of the relationship between quadriceps strength and physical function in individuals with knee osteoarthritis
Bibliographic record
Abstract
OBJECTIVE: To determine if quadriceps activation failure (QAF) moderates the relationship between quadriceps strength and physical function in individuals with knee osteoarthritis (OA). METHODS: Quadriceps strength and QAF were measured in 105 subjects (80 females) with radiographically confirmed knee OA using a burst-superimposition maximum voluntary isometric quadriceps torque test procedure. Subjects performed the Get Up and Go test as a physical performance measure of function and completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) as a self-report measure of function. A principal component analysis was performed to combine the Get Up and Go score and the WOMAC subscores into a single function score. Hierarchical regression analysis was performed to examine the ability of 3 models to predict physical function (strength = function; strength + QAF = function; strength + QAF + [strength x QAF] = function). Partial F tests were used to compare differences in R(2) values between each model. RESULTS: Each model independently predicted the principal component score for function. Adding the strength x QAF interaction term with strength to the model resulted in the highest prediction of function. The strength x QAF interaction indicated that subjects with lower levels of quadriceps strength and higher levels of QAF had lower levels of function than those with comparable levels of weakness but low levels of QAF. CONCLUSION: The magnitude of QAF serves to moderate the relationship between quadriceps strength and physical function. Physical function may be more severely affected by weakness of the quadriceps muscles in individuals with knee OA who have higher degrees of QAF than those who may have quadriceps weakness, but do not have QAF.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 | 0.001 |
| 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".