DR. LIEBERMAN: I think there is a number of key elements to good running form. The first is not to over stride. Over striding 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 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 in the time it takes the center of mass of your body to get over your foot, you are actually losing energy. The other thing that happens when you over stride is that you stick foot out in front of you and make your leg stiffer. And you have what is called an impact peak and you have this shock wave that ripples up your body. But when you land without an over stride you do not have that jolt of force and you are much less likely to get injured. It is just a better way to run.
Another key element to running is to land with a pretty flat foot. I think that most good runners tend to land on the ball of their foot. It just happens naturally. If you do not stick your leg out in front of you, you will not land hard on your heel. You will land on the ball of your fit or your mid foot stride, but it is a gentle landing. Do not lean. A lot of runners lean forward at the hips. That is another total evil. Be vertical from the hips up. If you can hear your feet, if your feet are landing really hard. If you are thumping as we call it in our lab, it as a sign that you are running poorly. The thump is the sound of the collision of your body hitting 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 if you are learning to run properly and you have not been doing this for a long time, listen to pain. Do not overdo it. Transition really slowly and gradually. Your body is not designed for this explicitly.
If you transition into learning how to run properly too fast, you are guaranteed to injure yourself. You have to adapt your body. Everybody can learn to run this way, or most people can learn to run this way, but you cannot do it overnight.