^i think he means duck out your boots. You definitely do not want them pigeon toed (toes pointing inwards) because that'll absolutely kill your knees haha. He definitely means duck out your boots, but everything else he stated I correct!
If you want to gain muscle for your legs, it's simple: workout! You'll only get what you put it. Calf raises, dead lift, and most of all, squats!! Do workouts to work your legs, and again, squats are one of the best!! Go for runs too and run hills. Strengthen your knees and quads and calves and the rest of your legs. That'll help a lot!!