How squatting position changes leg muscle squeeze
Effects of knee and hip flexion angle on region-specific and longitudinal compartmental muscle stiffness of the rectus femoris using shear wave elastography in male bodybuilders
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Muscle stiffness changed significantly with hip angle, but EMG showed no difference.
It’s widely assumed that EMG accurately reflects muscle effort and activation. This study shows mechanical tension can increase without any change in electrical signal—challenging a core assumption in exercise physiology.
Practical Takeaways
Try reclining your torso during leg extensions to increase mechanical tension in the upper rectus femoris, potentially boosting quad development.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Muscle stiffness changed significantly with hip angle, but EMG showed no difference.
It’s widely assumed that EMG accurately reflects muscle effort and activation. This study shows mechanical tension can increase without any change in electrical signal—challenging a core assumption in exercise physiology.
Practical Takeaways
Try reclining your torso during leg extensions to increase mechanical tension in the upper rectus femoris, potentially boosting quad development.
Publication
Journal
European Journal of Applied Physiology
Year
2025
Authors
Hiroku Mitsuya, K. Nakazato, T. Okada
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Claims (6)
When male bodybuilders flex their knees at a 30-degree angle, the upper part of a specific thigh muscle gets stiffer if their hips are straighter, suggesting how stretched the hip is can change how the muscle works.
When male bodybuilders flex their knees and push without moving their legs, the front thigh muscle feels stiffer than a neighboring muscle — and this difference depends on how much the hip is bent.
When bodybuilders push hard with their legs, the stiffness in a key thigh muscle changes depending on leg position—but the usual muscle activity sensors (EMG) don’t pick up these differences, suggesting they might miss some real muscle behavior.
In male bodybuilders, the top part of a big thigh muscle reacts more to hip position than the lower parts when the knee is bent slightly, showing that the muscle doesn't work the same way from top to bottom.
For male bodybuilders, changing the knee bend doesn't really affect a key thigh muscle's stiffness if the hip stays in the same position — but changing the hip position does seem to matter more.