The Claim
The leg extension exercise, despite being a single-joint movement, results in greater activation of the quadriceps femoris muscle group compared to multi-joint exercises such as squats and leg presses, due to more effective recruitment of the rectus femoris muscle.
What the research says
Roughly balanced
Support and challenge are close. The picture may shift as more studies come in.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
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.
See the scientific wording
Despite being a single-joint movement, the leg extension exercise provides more comprehensive quadriceps femoris activation than multi-joint exercises like squats or leg presses due to effective recruitment of the rectus femoris.
What the research says
3 studiesThe study shows that leg extensions build the front thigh muscle (rectus femoris) more than squats do, which supports the idea that this exercise works that specific muscle better.
The study found that leg extensions work the front thigh muscle (rectus femoris) better than leg presses, but both exercises work the rest of the quads about the same.
Study: Quadriceps EMG/force relationship in knee extension and leg press.
The study found that leg extensions don’t activate the quadriceps or the rectus femoris more than leg presses do — both exercises use the muscles similarly.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.