I'm a tall guy with a history of back problems, so I'm forced to do leg presses and avoid squats and deadlifts. I have made great gains in my leg strength, and have added over and inch to my thighs, and I'm even getting my inner thighs rubbing together when I walk, like big bodybuilding guys get.
My ass is still a too flat for my liking. How can I build my glutes without adding too much more mass where it makes it harder to walk normally? I never seem to get sore muscles around where I inject, but there is obviously a fair bit of muscle back there. Any suggestions? Thanks.
(My gym has a machine where the legs spread sideways against resistance, but it just seems to only hit the hip flexors.)