When you are in a forward body position there will be a small lean from the ankles so that your shoulder is aligned over your mid-foot. There is a straight line forwards from ankle through pelvis and shoulder with no bending at waist.
1. A forward body position allows us to use gravity to develop angular momentum and rotational energy when we run. Opinions differ in role of gravity but Svein Otto Kanstad, a physicist and former competitive runner suggests “We are falling forward, and our legs catch us,” he says. With each footfall a runner’s body actually rotates forward, pivoting on the foot in contact with the ground. “It is not a series of jumps, it is a series of rotations.” In a paper published at the end of 2015 Kanstad went on to say “Gravity is there, and it drives us forward, but we immediately kill it by the way we run,” he says. “Just by not being that killer, you can have 10 per cent more energy for free.”
Enjoy the Segway drill and let us know if you agree with Kanstad: Journal reference: Proceedings of the Royal Society A, DOI: 10.1098/rspa.2015.0287
2. A second, less contentious reason, is that a forward body position, where the body is correctly aligned from ankle to shoulder, allows for an optimal hip extension off the back foot. Optimal hip extension helps facilitate the recovery or swing phase of your other leg as it lifts off the ground and comes forward.
3. A forward body position also encourages correct foot placement under the body. Happily, correct foot placement under your centre of mass also means you are more likely to be landing on your mid to fore foot and not your heel so that you can make full use of the stretch shortening cycle which allows the elastic tissues of your lower limbs to act as springs. More free speed if we can get it right!
It is important to introduce these changes to your running gradually so that your tissues can adapt. This takes months, up to 18 months to be precise! So listen your body and don’t get too carried away!