Foot Positioning on Squat and Leg press to stress different muscles??

[WannaBPowerful]

Iv read a few different articles where pro's state that they position their feet different for squats and leg presses to put more of the stress on the hamstrings, the outer or inner quads. Problem is, they never say what position stresses what area. Can someone help me out here?

 

[SteelWeaver]

Deep squats, especially with a wider stance, stress the hams and glutes more, and the inner thigh muscles too. A narrower stance will hit the outer quad sweep more. Feet high on a leg press will stress hams and glutes more too, and again, a wider stance will hit the inner thigh area. BB or machine hack squats and front squats will place emphasis on the teardrop muscle.

But what can make the rectus femoris grow, I wonder?