Is your butt hard or soft? Your glutes are involved in more than you think. Locomotion, knee stabilization, back health, and a lot more. There are also small muscles deep in your glutes that are very important when it comes to stabilizing the knee. If you want to have healthy knees and strong glutes you need to train those muscles. Band walks, clam shells, monster walks, all work the glute medium, from there move into squats, deadlifts, single leg squats, lunging, step ups. These exercises all work the glute major. Which is what gives you that hard ass and everyone can use that. No more flat butts!!!!