How does pressure configuration affect Cobb angle during AIS brace casting?
Bibliographic record
Abstract
This work measured the magnitude and distance between pressures applied to the torso of AIS patients by an orthotist during brace casting. The instantaneous effect of the pressure configuration on Cobb angle was investigated using ultrasound. The objective was to use real-time measurements to confirm that pressure configuration affects Cobb angle predictably. Nine AIS patients undergoing casting for new braces participated in this pilot study (2 males, 7 females, aged 11-16, Cobb angles 16-44 degrees). An ultrasound scan was used to measure the patient's (baseline) Cobb angle. The orthotist then used a custom standing Providence system to apply corrective pressures - simulating a brace. A second ultrasound scan measured the new (corrected) Cobb angle. The orthotist could then try to achieve additional correction by adjusting the pressure magnitude/location. The process of adjusting pressures and ultrasound scanning repeated two or three times; the orthotist then chose the most satisfactory pressure configuration and performed the actual casting. The procedure produced 26 individual scans (including baseline scans) from the 9 patients. The magnitude of applied pressures was measured using inflatable air bladders fixed to the Providence pads. The air pressure was measured during the ultrasound scan. The distance between pads was measured and multiplied by the total pressure to create a torque-like measurement. Robust linear regression was used to relate pressure with Cobb angle correction, and torque with correction. Outlier points were removed if they fell more than 1.5 standard deviations from the regression line. Correlations between pressure/torque and correction were then measured. Two outlier points were removed - both belonging to a single patient. Pressures ranged from 16-113 mmHg. The major curves' correction ranged from 0-39%. Significant correlations existed between average pressure and Cobb angle correction (r = 0.86, p < 0.01), and average torque and Cobb angle correction (r = 0.82, p < 0.01). Cobb angle correction can be increased by increasing the applied pressure. Curves which allow larger spacing between the pressure pads should also expect larger correction. This pilot study is the first to validate these concepts in real-time using noninvasive ultrasound technology.
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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 | 0.000 | 0.004 |
| 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 | 0.001 | 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".