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How does the shape of a runner’s foot influence his foot-to-ground contact pattern?

Earlier theories held that the foot-to-ground contact pattern is influenced mainly by the shape of the longitudinal arch. Specifically, it was thought that runners with high-arched feet tend to emphasize supination (too little pronation), while runners with low-arched or flat feet tend to overpronate. However, recent studies have shown that this is not the case. Quite generally speaking, any attempt to infer from the static (stationary) to the dynamic (moving) state is prone to error. This is due to marked interindividual differences in the overall movement pattern, in particular differences in the angular motion of hips, knees and ankles. It is this dynamic movement pattern that largely determines the magnitude of forces which arise.

Why are running and walking analyzed separately?

For one thing, what has been said above also applies to the two different movement patterns of running and walking. A person who exhibits pronounced pronation need not necessarily do the same in running, and vice versa. For another, walking places different requirements on a shoe than does running. This is automatically taken into account in the analysis.

Why does Achillex measure the progression of pronation as well as of impact force?

Unlike other systems Achillex measures the progression of both pronation and impact force. Firstly, this makes it possible to detect any need for more damping and to give an appropriate recommendation. Secondly, the forces can be set in relation to one another when analyzing a person’s running style. Pronation forces which occur before the runner’s entire weight rests on the foot are treated differently than those which arise under full load. The pronation data are particularly important when it comes to recommending a support. In the event of small impact forces the degree of pronation can be reduced by using a flat sole, thus bringing the foot closer to the ground.

Why are measurements with Achillex performed at 400 Hz? Why not at a higher or lower frequency?

Frequency analyses of measured running data have shown that all relevant data are within the range of 0-100 Hz. A minimum of 200 Hz is required in order to capture these values, while 400 Hz allows optimal signal measurement.

Why does the runner wear reference shoes rather than run barefoot during measurements?

In most cases measurements are performed on the hard floor of a sports shop. Under these conditions most runners tend to run only on their toes, i.e. rather than use their heels they take the entire impact with the front of their feet. Measuring pronation is pointless in this case. This applies all the more to measurements performed outdoors, where running barefoot is usually not feasible. Another reason is that the impact and pronation forces during barefoot running are very different from what they are when running in shoes. Drawing inferences about running in shoes would be a bit like comparing apples and oranges.

Why is it important that measurements are performed during unconstrained running and at the runner’s own pace?

Many studies have shown that a person’s running style on a treadmill is different from his normal running style. Usually the difference is not so great, but in some cases it can be quite dramatic. The deviation is different for each individual and not predictable. The treadmill is not well-accepted by most customers. Many are reluctant to use it, and for many it is simply too dangerous. Another reason is that often the treadmill runs at a different speed from what they are accustomed to. Since impact and pronation forces grow markedly with increasing running speed, a different running speed can result in the recommendation of a different type of shoe.

How important are comparative measurements?

The purpose of performing comparative measurements with the recommended shoe is primarily to compare different shoes with each other and find the most suitable one. However, measurements on the chosen shoe are urgently recommended even if a comparison of different shoes is not desired. This is because not all runners respond to a given shoe in the same way. Providing a pronation support does not necessarily reduce the degree of pronation. In not a few runners it actually has the opposite effect. The same applies to the degree of damping. The reason for this is that the runner senses the change brought about by the shoe and unconsciously changes his movement pattern in response. This can lead to overcompensation and hence to seemingly paradoxical results. For example, if the runner perceives the reduction of impact force brought about by increased damping, he may change his movement in a way that brings more force to bear on the ground. As a result, the impact forces might be the same or even greater than before.

Where can I do a gait-analysis with Achillex

Please go to customer for details.

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