There is a trend in running shoes for trying to move away from the heel strike. The two major reasons for this have to do with the transfer of energy from the working muscle into forward motion, and the potential for injury that may come, over time, with heel strikes.
Not all running shoes make the shift though – for example the Mizuno Wave Enigma, which explicitly works for heel strike neutral runners. It seems to take the view that there are people out there who will naturally heel strike, or whose leg muscles have been elongated and contracted over years of heel striking into a shape that won’t find the toe strike comfortable at all – so instead of encouraging the runner to change her form, it works by cushioning and transferring the impact through the foot.
The basic science of the running shoe can be split into two categories: the shoe that tries to prevent unnatural, improper or rolling foot strikes from injuring the runner; and the shoe that attempts to correct for unfortunate striking positions by cradling the foot forward and essentially forcing the runner onto her toes. This second category has developed in recent years through an increasing recognition that natural running, or minimalist running, may lessen the occurrence of lower back, hip and knee injuries in frequent runners.
The argument essentially runs as follows. The more cushioning you put under a foot, the less feedback it is able to deliver from the ground. This means the runner may effectively be able to strike the ground quite hard with her foot in an unnatural position – a position that the running leg would not normally be able to maintain.
The bounce delivered by compressing a thick cushioning sole hard against the ground generates enough returned motion to propel the runner forwards faster than she would be going if she were running naturally: ergo, the experience of running in heavily cushioned shoes makes a person feel that she is running better, when in fact she may be running worse.
The reality is a lot more complex than the arguments for or against. Natural runners are anatomically correct: the human leg and foot does hit the ground in a manner that would be unsustainable without heavy cushioning, when a person runs in a heel striking shoe with a thick sole. In some cases this can and will lead to injury.
However, there’s another part to the argument which has yet to be truly enunciated. Humans are the only animals in the world that have been able to sidestep the demands of evolution by inventing multiple tools, which help them operate in otherwise unfamiliar environments. The cushioning on a running shoe sole, provided it is created with the best science to hand, can be thought of in this way. It’s like running with padded feet, as a cheetah or a dog might do: only we’ve not had to spend hundreds of thousands of years evolving them.
All runners have different gait and different problems. The key is finding the shoe that works for you personally.
Maria is a long distance runner. She has recently written an article comparing the Mizuno Wave Enigma with the Brooks ASR.