Here is a great video a sports medicine doctor did showing a side by side comparison of a woman running barefoot vs in shoes. She was given no instruction, just told to run. The point of the video is to show us how shoes create an artificial range of motion in the stride.
In the beginning, look at the freeze frame of the runners thigh. In the left/ barefoot video, notice the lack of total flex in the thigh. In the right/ in shoes video, the thigh is completely flexed, and the IT band (ilieo-tibial band)is rigid. This is why so many runners have tight and painful IT bands, and hip, knee, and low back pain.
Here is another video of the doctor demonstrating effective barefoot running.
The doctor mentions in another area that her runs in Adidas “Adizeno” shoes. There are also neat shoes called “Vibram 5- Fingers”.
There is a course that “retrains” people how to run this way, especially if they have been running for years and are in the habit of “heel striking” called the POSE method.
Well, I am off to experiment on my treadmill now!