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https://anotepad.com/notes/rena39pa
What are a few of their undesirable habits? Well for one, NOT bending the knees enough; which causes a lot of impact for a ankles and knees. And two, developing the practice of landing for a heel, instead of the forefoot. This, basically stops the runner's forward momentum, and 'puts the brakes on.' Also, it sends a 'shock' through the general leg, beginning from the heal, and sending it up through the knee. Not good, and a major reasons why runner's in padded, expensive shoes, claims McDougall, suffer more