Changes In Muscle Activation Patterns And Kinematics While Learning The Bilateral Barbell Squat
Bibliographic record
Abstract
While the barbell squat has been subjected to many biomechanical analyses, it is not known how the kinematics and muscle activation profiles will change as an individual learns how to perform the movement. Previous work using different motion patterns have noted decreased variability in movement patterns between repetitions as an individual learns a new movement pattern. PURPOSE: The goal of this work was to document changes in variability of kinematic and muscle activity patterns while individuals learn to perform a standard bilateral barbell squat. METHODS: Ten university age females with no prior barbell squatting experience were recruited. The participants attended four weekly sessions where they performed 4 sets of 10 squats at 50% of their one-repetition maximum (1RM) while receiving feedback on their squatting technique. During the squats the participants had their motion captured in the sagittal plane using a high speed video camera and electromyography (EMG) was recorded from 8 lower-limb muscles that were involved in the squatting motion from the right lower-limb. Prior to the first session and at the end of the last session a 1RM test was performed to determine the maximum capacity for the barbell squat. RESULTS: Despite using a load where a strength adaptation would not be expected, the participants demonstrated a significant increase in 1RM across the study (50.1±8.6 kg vs 57.1 ± 10.0 kg; p < 0.05). Interestingly, most changes in kinematic variability occurred at the ankle joint, where increased variability was observed across the 4 sessions (p < 0.05). It was also observed that the participants were squatting deeper as sessions progressed, as measured by the angle of the thigh segment (p < 0.05). Rectus Femoris (RF) showed decreased variability across the sessions (p < 0.05). CONCLUSIONS: Although an increase in 1RM was found, this improvement is likely due to changes in technique rather than strength. Our findings that the ankle increased in variability may be supported by the uncontrolled manifold hypothesis, which states since attentional focus was on the hips in this study (due to the nature of our feedback), that variability may increase in other areas. Changes in muscle activity of RF may indicate that the participants became more adept at coordinating the hip and knee joints during the squat.
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) | 0.002 | 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".