CARDIORESPIRATORY AND MUSCLE OXYGENATION-BLOOD VOLUME RESPONSES DURING INCREMENTAL LIFTING AND LOWERING IN HEALTHY MEN
Bibliographic record
Abstract
Fatigue of the erector spinae muscles during repetitive lifting has been associated with low back injury. Reduced aerobic capacity, decreased oxygenation and compromised blood flow have been implicated in low back muscle fatigue. PURPOSE: To examine the relationship between the peak aerobic power (peak VO2) and localized muscle oxygenation (Mox) as well as blood volume (Mbv) during incremental lifting and lowering in healthy men. METHODS: Fourteen asymptotic males (Mean ± SD for age, height, body mass and lifting peak VO2 were 29.7 ± 8.2 yr, 1.74 ± 0.07 m, 76.4 ± 8.9 kg, 37.2 ± 8.3 ml/kg/min respectively) consented to an incremental lifting and lowering test to voluntary fatigue. After 2 mins of baseline measurements, the test was initiated at 5 kg and a frequency of 10 lifts/min. The load was increased by 2.25 kg every minute until voluntary fatigue, followed by 4 mins of recovery. Cardiorespiratory responses were monitored continuously throughout the test using a wireless metabolic system (Sensormedics VmaxST, CA). The Mox and Mbv were recorded from the right erector spinae muscle at the L3 level, 3 cm from the spine using near infrared spectroscopy (Micro Runman, NIM Inc., PA). The data were collected on-line and averaged over 20 sec intervals. The Mox and Mbv responses were expressed as the relative change from the resting value. RESULTS: The cardiorespiratory measurements increased systematically during incremental lifting and lowering, with most of the subjects terminating the test due to localized fatigue of the back muscles. Mox decreased systematically during incremental lifting and lowering until the peak VO2 was attained. A leveling off was observed in some subjects towards the end of the test. Mbv increased until 50% to 60% peak VO2 and then leveled off in most subjects. Significant correlations (P < .05) were observed between peak lifting load vs absolute and relative peak VO2 (r = 0.55 and 0.74 respectively). However, none of these variables were significantly related to Mox and Mbv during lifting (P > .05). CONCLUSION: Enhanced lifting and lowering capacity is associated with a high aerobic power that is independent of localized muscle oxygenation and blood volume changes in healthy men. Support: Alberta Workers' Compensation Board.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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".