Increasing cadence and stride length, how often do we hear and read this? Too often! The focus of proper run mechanics should be on getting the athlete to place the foot down underneath the center of mass. When the foot makes ground contact, the foot and knee should be in alignment and the shin perpendicular to the ground. Speed comes from applying force to the ground in the correct way. Once an athlete understands and is able to apply force, correctly, an athlete will naturally run faster, and range of motion and cadence will increase.
Focusing on correcting arm swing can have a huge impact on your running. For distance runners, hands should stay close to the body, with elbows sticking out as much as required to make this easy. Hands should move on a diagonal pathway, from your breastbone to your sides. If you are engaging your core (and you should be) the turning of your upper body causes your hands to swing to the midline. The lateral movements of your spine, which shift weight from one foot to another, result in your hands moving in a more circular movement.
If you over stride, keeping your hands close to your body will keep your feet landing close to your center of gravity. If your hand is far from your chest, the torso and head move backwards to compensate, and the push from the foot in late stance ends up somewhere between them to move you forward.
When we run we need to push ourselves forward and upward from the ground. Improper arm swing results in using more energy: pulling shoulders back, forcing the chest upward which results in it being impossible to lean forward. When our hands are close to our chest we lean forwards and are in a better position of power and for our bodies to be pushed forwards.
Lastly, the arm swing comes from the shoulders. Driving the elbows back and up. This is what aides stride length. There is no driving the arm and elbow forward as this should happen naturally.
I suggest playing around with positioning of hands and distance of arms from torso to see how it alters your running form and the ability to create force.
