Lower Limb Biomechanics During Drop-Jump Landings on Challenging Surfaces in Individuals With Chronic Ankle Instability
Bibliographic record
Abstract
CONTEXT: Individuals with chronic ankle instability (CAI) exhibit impaired lower limb biomechanics during unilateral drop-jump landings on a flat surface. However, lower limb biomechanical adaptations during unilateral drop-jump landings on more challenging surfaces, such as those that are unstable or inclined, have not been described. OBJECTIVE: To determine how unilateral drop-jump landing surfaces (flat, unstable, and inclined) influence lower limb electromyography, kinematics, and kinetics in individuals with CAI. DESIGN: Descriptive laboratory study. SETTING: Biomechanics laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 22 young adults (age = 24.9 ± 4.9 years, height = 1.68 ± 0.08 m, mass = 70.6 ± 11.4 kg) with CAI. INTERVENTION(S): Participants completed 5 trials each of unilateral drop-jump landings on a flat surface (DROP), an unstable surface (FOAM), and a laterally inclined surface (WEDGE). MAIN OUTCOME MEASURE(S): Electromyography of the gluteus medius, vastus lateralis, gastrocnemius medialis, peroneus longus, and tibialis anterior muscles was recorded. Ankle and knee angles and moments were calculated using a 3-dimensional motion-analysis system and a force plate. Biomechanical variables were compared among tasks using 1-dimensional statistical nonparametric mapping. RESULTS: During DROP, greater ankle-dorsiflexion and knee-extension moments were observed than during FOAM and WEDGE and greater vastus lateralis muscle activity was observed than during FOAM. Greater ankle-inversion and plantar-flexion angles were noted during FOAM and WEDGE than during DROP. Peroneus longus muscle activity was greater during DROP than during FOAM. During FOAM, greater ankle-inversion and knee-extension angles and ankle-inversion and internal-rotation moments, as well as less peroneus longus muscle activity, were present than during WEDGE. CONCLUSIONS: The greater ankle-inversion and plantar-flexion angles as well as the lack of increased peroneus longus muscle activation during the FOAM and WEDGE conditions could increase the risk of recurrent lateral ankle sprain in individuals with CAI. These findings improve our understanding of the changes in lower limb biomechanics when landing on more challenging surfaces and will help clinicians better target deficits associated with CAI during rehabilitation.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".