Starting Fast Walking
You will find that if you concentrate on moving your legs and arms you will be able to walk properly. In the past you have been able to tell yourself to walk and it happens, without you having to think what your legs and arms are doing.
Carry out a little test to illustrate this point. Stand upright with your feet, shoulder width apart. Then, with somebody holding one of your arms, put all your weight onto your left foot so that you are able to lift your right foot up in front of you, without falling over, with the knee held straight. See how far you are able to stick that right leg out in front of you. You will find that you are able to stick it out quite far.
Then, put all your weight on the right foot and lift your left leg up in front of you, with the knee held straight, and see how far you are able to stick that left leg out. No doubt it will be the same as the right leg.
If you were able to stick both legs out to at least 30 degrees, which is normal, you will ask yourself, why don't you do that when you are walking. The answer is that when you do it subconsciously, it is not working properly and when you do it consciously, it works perfectly.
So all you have to do now is to consciously think about putting all your weight on one leg and think of moving that leg forward and landing on the heel of that foot, then doing the same with the other leg.
After getting used to doing that, with somebody holding your arm, for at least a week, you can then concentrate on holding the weight of your body on the ball of the grounded foot, so that when the other heel hits the ground, your body weight is being supported on that back foot.
Soon you will be walking, consciously, all the time, without having to concentrate too hard.
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Here are some videos showing you all about it.