The Study
Quadriceps EMG/force relationship in knee extension and leg press.
This study is like taking a snapshot of how muscles send signals when people push with their legs in two different ways. It shows what happened in 9 guys, but it doesn’t prove one thing caused another or that it would be the same for everyone.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists looked at how leg muscles turn on when men push as hard as they can using two different leg exercises. They measured muscle activity at different effort levels.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 520 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, this helps understand which muscle signals best match how hard someone is pushing, especially for measuring strength in studies or rehab.
- 2Muscle activity didn't go up evenly with effort.
- 3The outer thigh muscle (vastus lateralis) increased steadily, but others did not.
- 4Both exercises used the big thigh muscles the same way.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Medicine and science in sports and exercise
Year
2000
Authors
Björn A. Alkner, P. Tesch, H. Berg
Related Content
Claims (4)
Even though leg extensions only move one joint, they might work your front thigh muscles better than squats or leg presses because they really target one specific muscle in the quad.
When healthy guys push with their legs at a 90-degree bend, their quad muscles don’t fire in a straight line with how hard they push — the muscle activity changes unevenly as they push harder from 20% to 100% effort.
When healthy guys push with their legs, the electrical activity in one specific thigh muscle (vastus lateralis) goes up steadily with how hard they push — unlike two other thigh muscles — so it might be a better way to measure how much force their whole quad is producing.
When men push with their legs using different exercises but at the same knee angle, their thigh muscles turn on in a similar way, even though one exercise uses more joints than the other.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.