Knee and Ankle Joint Angles Influence the Plantarflexion Torque of the Gastrocnemius
Bibliographic record
Abstract
BACKGROUND: The gastrocnemius (GA) is the lone bi-articular muscle of the leg, crossing both the knee and ankle. As with any bi-articular muscle, both joints affect its length/tension curve. The role of the GA as a plantarflexor is firmly established; however, no current research has investigated how changes in knee and ankle joint positions on its ability to generate a plantarflexion (PF) torque. This paper reports on the PF force generated by the GA at specific knee and ankle joint combinations. METHODS: The right GA of 26 participants was electrically stimulated via surface electrodes following a standardized protocol at 24 knee and ankle joint combinations. Three stimulations were applied at each of the 24 positions. Data were recorded on three dependent measures: the passive moment, which was the PF moment created by the tissue without stimulation, the maximum moment, which was the highest PF moment during the stimulation and included the passive moment, and the stimulated moment, which reflected the PF moment during stimulation minus the passive moment. RESULTS: A straight knee and dorsiflexed ankle create the position in which the GA generates the greatest PF moment, but it is also the position of greatest length. This finding is in contrast to conclusions from previous research with bi-articular muscles, which has consistently shown that the greatest length is not a muscle's optimal length. The full ranges of motion for the knee and ankle apparently do not elongate the GA beyond its optimal length for producing a PF moment. Clinicians commonly evaluate GA status with the patient seated and the foot subject to gravity. CONCLUSIONS: The present results indicate that manual testing of the GA in isolation should be performed, whenever possible, with the knee extended and the ankle dorsiflexed to potentially elicit the maximum PF torque from the GA.
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) | 0.003 | 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".