Stepping up? Use Your Butt!
Walking uphill or climbing stairs is a great way to develop the hip and butt muscles for the posterior driven gait. But how you step up matters for your butt! Put your foot up onto the next step, and then observe how you tend to step up. Do you lean forward and use your hands on your knee? That's fine, but probably shows your legs may be tired or not have the strength to carry your body and so are utilizing the help of the arms. Does your knee shift forward over or past the toes and do you lean your body forward over the leg first before stepping up? That's also fine, but shows that your habit is to mostly use the quadriceps and your knee joints for walking up. I want to emphasize that any method of getting you where you want to go is the body's intelligence at work. But the body will tend to default to where it has the most strength already. So, to develop more hip and butt strength try this: rather than leaning your body forward or shifting your knee forward, when you step the foot up, keep that knee vertically over the ankle (don't let it shift forward), and use the leg to push down and pull back. As the leg straightens your body should be pulled up and on top of the leg. It may be challenging but this will develop that hip and butt strength for your posterior driven gait.
Once again:
Step up
Try to keep the knee vertically over the ankle
Push the leg down and pull back to bring your body up over the leg
Try to keep your body upright.
Afterwards, when you walk on flatter ground you may really feel that posterior driven gait!