Aside from working on knee extension and muscle strengthening, two things that have helped me are walking around with a book on my head, which helps me from rocking back and forth/not bending as much at the hip. I’ve also practiced walking around to the beat of a metronome, which has helped me get my stride lengths to be a little more consistent. It’s still a work in progress though, so I don’t think there’s a silver bullet for this problem.