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Record W1554854517

Gear Ratios in the Ankle-Foot System

2011· article· en· W1554854517 on OpenAlexaffvenue
P. Eng

Bibliographic record

VenueJournal of undergraduate research in Alberta · 2011
Typearticle
Languageen
FieldMedicine
TopicSports Performance and Training
Canadian institutionsUniversity of Calgary
Fundersnot available
KeywordsAnkleTorqueIsometric exerciseKinematicsGround reaction forceMoment (physics)MathematicsPhysicsPhysical therapyAnatomyMedicine
DOInot available

Abstract

fetched live from OpenAlex

Gear ratios in locomotion can be defined as the ratio of lever arms between the ground reaction force (GRF) and the calf muscle to the ankle joint. A resultant change in torque can be developed by either lengthening the distance of the GRF arm, or by altering the direction of the GRF. Studies on sports equipment such as speed skating and bicycling have shown that altering the gear ratios can affect performance. The purpose of this study was to investigate the effects of gear ratios on ankle joint moment and power generation. Seven male subjects participated in the study (US size 9). Each subject performed sprints out of blocks in three conditions: a control, and two modified shoe conditions with carbon plate insoles inserted, one size 9 and one of size 11 adjusted to fit a size 9 runner. Kinematic and kinetic data were collected from the first stride out of the blocks and used to calculate ankle angle, torque, velocity and power. In a separate session, isometric and isokinetic measurements of the ankle plantarflexor strength were made in order to establish the torque-angle and torque-velocity relationships for each individual. Results showed that stiffening the sprint spike increased the gear ratio about the ankle. A larger torque was generated, mainly due to the shift in ankle range of motion toward a more dorsiflexed position. This can be supported by the torque-angle relationship determined from isometric strength measurements. Angular velocity decreased, offsetting the torque increase. As the result, no significant changes in power and energy produced were observed. Looking at individual results, two subjects showed a large increase in torque generation without decreasing angular velocity resulting in increased power, which is valued as increased sprinting performance, with a larger gearing ratio.

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 imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.007
Threshold uncertainty score0.023

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0000.001
Scholarly communication0.0010.001
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0070.002

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.

Opus teacher head0.152
GPT teacher head0.376
Teacher spread0.224 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

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Citations0
Published2011
Admission routes2
Has abstractyes

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