I think there's a number of key elements to good running form, and the first is not to overstride. Overstriding is when you stick your leg out in front of you, and you land with your foot in front of your knee, and really way in front of your hip. A lot of people think that they're running hard when they do that. You know why? Because they are running hard! Because when you stick your leg out in front of you, you actually decelerate, from the time it takes the center of mass of your body to get over your foot. You're actually losing energy.
The other thing that happens when you overstride is that when you stick your foot out in front of you and make your leg stiffer. And you have this what's called an impact peak and this shockwave travels up your body. But when you land without an overstride, you don't have that jolt of force. And you're much less likely to get injured. It's just a better way to run.
Another key element to running, is run with a...land with a pretty flat foot. I think most good runners tend to land on the ball of their foot. It just happens naturally. If you don't stick your leg out in front of you, you will not land hard on your heel. You'll land on the ball of your foot or your midfoot strike. But it's a gentle landing.
Don't lean. A lot of runners lean forward at the hips. That's another total evil. Be vertical from the hips up. If you can hear your feet, if your feet are landing really hard, if you're thumping as we call it in my lab, then you're running poorly. That thump is the sound of the collision of your body with the ground. Running should be light and gentle and collision-free. So if you're making a lot of noise, you're running poorly.
And then finally, the most important thing is if you're learning to run properly, and if you haven't been doing this for a long time, listen to pain. Don't overdo it. Transition really slowly, gradually. Your body is not just designed for this instantly. If you transition to learning to run properly too fast, you are guaranteed to injure yourself. You have to adapt your body, right? You know, I think everybody can learn to run this way. Most people can learn to run this way, but you can't do it overnight.