Running better, from head to toe.
Head Tilt How you hold your head is key to overall posture, which determines how efficiently you run. Let your gaze guide you. Look ahead naturally, not down at your feet, and scan the horizon. This will straighten your neck and back, and bring them into alignment. Don’t allow your chin to jut out.
Shoulders Shoulders play an important role in keeping your upper body relaxed while you run, which is critical to maintaining efficient running posture. For optimum performance, your shoulders should be low and loose, not high and tight. As you tire on a run, don’t let them creep up toward your ears. If they do, shake them out to release the tension. Your shoulders also need to remain level and shouldn’t dip from side to side with each stride.
Arms Even though running is primarily a lower-body activity, your arms aren’t just along for the ride. Your hands control the tension in your upper body, while your arm swing works in conjunction with your leg stride to drive you forward. Keep your hands in an unclenched fist, with your fingers lightly touching your palms. Imagine yourself trying to carry a potato chip in each hand without crushing it. Your arms should swing mostly forward and back, not across your body,between waist and lower-chest level. Your elbows should be bent at about a 90-degree angle. When you feel your fists clenching or your forearms tensing, drop your arms to your sides and shake them out for a few seconds to release the tension.
Torso The position of your torso while running is affected by the position of your head and shoulders. With your head up and looking ahead and your shoulders low and loose, your torso and back naturally straighten to allow you to run in an efficient, upright position that promotes optimal lung capacity and stride length. Many track coaches describe this ideal torso position as “running tall” and it means you need to stretch yourself up to your full height with your back comfortably straight. If you start to slouch during a run take a deep breath and feel yourself naturally straighten. As you exhale simply maintain that upright position.
To read the rest of the article: http://www.runnersworld.com/running-tips/perfect-form