The best overall exercise I’ve found for improving the overall biomechanics of the lower body is the elliptical machine. Specifically, the commercial grade LifeFitness (like the 95xi?). The LifeFitness has a longer stride length than most of the other ones I’ve used. They key to using the elliptical for fixing your crappy biomechanics is to always keep both feet firmly planted on the platform at all times. Don’t let your heels lift up as your feet cycle around. Keep your toes pointed straight and keep your knees tracking to the outside of the big toe. BTW, it is best to do this barefoot. The beauty of the elliptical is that since your feet are always planted you have something to push against to create torque. The elliptical is a low impact and easy way to get thousands of repetitions in while maintaining proper form. 

Before last Christmas I couldn’t keep both heels planted to save my life. I had so much tightness in the right hip capsule that the femur wanted to push up through my pelvis as the right side cycled around.The severely limited range of motion on the right side was causing the left foot to lift entirely off the platform. After about 15 minutes, with quite a bit of pain, things finally loosened up to the point where I could keep both feet planted with little pain. Four of five elliptical workouts did more for my hip than 5 months of physical therapy. I still have ankle problems I’m working on, but it’s getting there.