We hear this a lot... glutes (the muscles that make up your rear end) don't fire, they don't work, they are turned off.
How does that happen? Let's test it right now... If you are sitting, stand up. Did you do it? Congrats, your glutes work.
So what happened? Here is a 3 minute video explaining how it isn't that your glutes don't work, but it is more likely that your movement pattern is altered (and yes, we can get it back), or that you really just aren't using your glutes.
And what happens when you don't challenge and use muscles in the body? That is right! They atrophy! They weaken and shrink. See... I knew you were listening!
So check out the video and then head out for a walk, even just 5 min, and notice your walking gait. Notice positioning.
Let me know how that goes!