This is a good video analysis of the elite Boston Marathon runners' mechanics. Inspite of different body builds, certain elements are universal.
- Upright torso
- Great range of motion in the hips (>90 deg)
- Powerful extension of the hip of the rear leg
- Strong thighs that don't collapse when they land on the lead leg
- Not much vertical movement of the torso, even though the feet come several inches off the ground