Running speed and endurance is an extremely important attribute is numerous sports. Though training methods, running coaches, and speed coaches are very beneficial, an athlete’s posture is a huge factor in speed and endurance.
Let’s say we have 2 people of exact equal build, size, and limb length. One person stands with his feet perfectly straight while the other is toed out (duck footed) about 15 degrees. If both people took the exact equal numbers of steps, when the one with straight feet was 100 feet from the starting line, the one who was toed out would be 15 feet behind. Why did this happen?
The laws of physics state for every force, there is an equal and opposite force. So when a person runs and their foot pushes off the ground at a certain angle, the ground pushes against the foot with equal force in the opposite direction. So when the person with straight feet pushes off the ground (the force of the foot is pushing straight back), the opposing force pushes directly forward. However, when a person is toed out 15 degrees, the opposing force pushes diagonally forward. Since the shortest distance between 2 points is a straight line, the person with the straight feet ends up ahead given the exact same number of steps taken.
With this in mind, we see can see the direct correlation with running speed. The person with proper alignment may not move his limbs faster than the person who is misaligned, but the appearance of speed comes from more economical movement.
As far as endurance, we see that the person who is toed out needs to take a great number of steps in order to cover the exact same distance as the person who is properly aligned. A person who was misaligned could cover that same distance in the same amount of time, however, it would require larger or faster steps and either option would require a greater expenditure of energy.
If there is such a great effect on speed and endurance just by having a person being toed out, imagine the effect when that is combined with numerous other common postural dysfunctions. Therefore, you can definitely see that having proper alignment can not only enhance performance, but also give a slight advantage to the competitive athlete.