Differences In Chronic Electromyography Recordings Between Community- And Retirement-dwelling Older Women
Bibliographic record
Abstract
Chronic electromyography (EMG) measures are common in occupational studies where they are used to understand work-related injuries. Recent studies have compared chronic EMG during daily life between young and old men and women (Harwood et al. 2008) and between old women across states of frailty (Theou et al., 2010). These studies demonstrated an age-related increase in low-threshold electromyography (EMG), which was reported to be greater in women compared with men, and EMG differed across states of frailty. PURPOSE: Measure upper and lower limb muscle activity using EMG in community- and retirement-dwelling older women for a 8-hour typical day. METHODS: Community- (n=9, 80±4 yrs) and retirement-dwelling (n=9, 84±6 yrs) older women participated. Surface EMG was recorded from the biceps brachii, triceps brachii, vastus lateralis, and biceps femoris of the self-reported non-dominant side for a 8-hour typical day. Signals were sampled at 1000Hz, stored on an MMC flashcard and imported into Spike 2 Version 5™ for custom script analysis. Isometric maximum voluntary exertions (MVE) were performed to normalize EMG data. An EMG burst was quantified as a period of muscle activity more than 2% of MVE for a duration longer than 0.1 sec. The number, mean duration, peak amplitude of bursts and the percentage of total recording time occupied by bursts were examined. RESULTS: The number of bursts in retirement-dwelling women was 22% greater (p=0.005) than the community-dwelling women (p<0.01). Peak burst amplitude was 42% less (p=0.005) in retirement-dwelling women compared with community-dwelling women. The burst percentage and duration were similar (p>0.05) between community (40±4.5% recording time, 1.1±0.2 sec/burst) and retirement groups (43±4.5% recording time, 1.1±0.2 sec/burst). CONCLUSIONS: Retirement dwelling older women had more bursts of lower amplitude compared with community-dwelling older women and these differences might be indicative of decreased muscle function in the former group. Supported by: NSERC
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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 | 0.001 |
| 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) | 0.002 | 0.001 |
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".