Doing leg extensions might grow your front thigh muscle more than leg presses, even though both workouts work the other big thigh muscles just as hard.

Doing leg extensions (kicking your leg out while sitting) makes the front thigh muscle right above your knee grow more than doing leg presses (pushing a heavy platform with both legs).

For people who don't usually work out, using a knee extension machine grows the front thigh muscle much more than using a leg press machine.

The rectus femoris muscle exhibits greater hypertrophic adaptation to isolated knee extension exercises than to compound movements involving hip and knee flexion due to biomechanical limitations in force production during multi-joint movements.

If you want to make the front part of your thigh (rectus femoris) bigger, leg extensions work better than leg presses — after 12 weeks, leg extensions made it grow 12% more than leg presses did.

Different leg exercises make different parts of your thigh muscles bigger — leg extensions grow the front part, squats grow the lower outer part.