I have watched runners pass in front of my house and being a retired physical education professor in kinesiology, I tend to look for common posture problems that many of the runners display. There are two common errors in running form that stand out the most frequently.
One is the tendency to lean forward. Going back to Coach Bill Bowerman from the University of Oregon, who wrote about keeping an erect posture when running for more speed, this includes sprinters as well as long distance runners. Some runners think that if they want to run faster, they have to lean forward. Sprinters in the blocks lean forward for a few strides but after those few strides they assume an erect posture.
Two problems occur when a runner leans forward. One is the lead leg and knee will not come up as high because of the pelvic tilt facing downward. The second problem is the foot strike will often be in front of the body acting as a brake to forward movement. The foot should be coming backwards when it makes contact with the ground. When the weight of the body is over the foot it should be directly underneath the body for maximum efficiency. The faster you run the higher the knee lift tends to be and the bend at the knee is closer to maximum. This allows for a faster movement forward of the leg since the length is lessened. With the runner leaning forward this higher knee lift is hindered slightly and the possibility of the foot being in front of the weight of the body acting as a slight braking action occurs.
