It is necessary to fix the running shoe model. What about motion control, cushioning, stability, and pronation? Eliminate them all. It's more than
It is necessary to fix the running shoe model. What about motion control, cushioning, stability, and pronation? Eliminate them all.
It’s more than barefoot running or minimalism versus running shoes. This is the “either/or” situation that many people portray. It goes deeper than that. It’s not that shoe company owners are evil or out to make money. Although shoe companies might be achieving the goals they have set, it is possible that the goals they are aiming for may not be what they need to achieve. Running shoes are built on a flawed paradigm.
Running shoes are based on two fundamental premises: impact forces and pronation. They are designed to limit impact forces and avoid overpronation. This has resulted in a classification system that is based on motion control, stability, and cushioning. This system may not be able to stand on its own. Are we focusing on the wrong things 40+ years?
Let me start with the usual statistic that 33-56% of runners are injured each year (Brugger man 2007, 2007). This is quite amazing when you consider it. There are many injuries, so let’s take a look at what shoes should do.
Shoes are based on the idea that pronation and impact forces are what cause injuries. Running has become a curse because of pronation. The motion control shoes have been a popular way to limit pronation. Pronation is based on the idea that excessive pronation causes rotation of lower legs (i.e. The main idea behind pronation is that overpronating causes rotation of the lower leg (i.e.,. This is why running shoes are designed to reduce pronation. Running shoes were designed to align the body properly. But is it really necessary to align properly?
The pronation paradigm is based on two things: (1) overpronation can cause injuries, and (2) running shoes may alter pronation.
We can see that there are many studies that don’t support the idea of pronation causing injuries. Wen et.al. He found that marathon runners were not at risk from lower extremity alignment (1997). Wen et. al. He concluded (1998) that minor variations in the alignment of the lower extremities do not seem to be significant risk factors for running-related injuries. Similar conclusions have been reached in other studies. Nigg et. al. A 2000 study showed that ankle and foot movement could not be used to predict injury in large groups of runners.
If foot pronation/foot movement does not predict injury or reduce the risk of injuries, it is time to question whether or not this concept is sound.
The second question is: Does shoes actually alter pronation? There are many ways that motion control shoes can reduce pronation. Many people insert a medial pin or similar device. Stacoff (2001) tested several motion control shoes and found no alteration in pronation or changes to the kinematics. running shoes Butler (2007) also found no difference in peak propensity between cushioning and motion control shoes. Dixon (2007) also found similar results, showing that motion control shoes didn’t reduce peak eversion or pronation and did not alter the pressure concentration.
This double-whammy is a big deal for motion control shoes. Motion control shoes are not designed to alter pronation and prevent excessive pronation from causing injuries.
Running injuries can also be caused by impact forces. It is believed that the more impact force is placed on the lower leg, the greater the stress to the foot/leg, which can lead to injuries. Running shoes, especially cushioning ones, can be used to combat this fear. Let’s take another look.
First, does cushioning footwear do its job?
Wegener (2008) tested the Brooks Glycerin and Asics Gel-Nimbus to reduce plantar pressure. The shoes were able to do their job !…. but the areas where it reduced pressure was highly variable. Meaning that pressure reduction varied between forefoot/rearfoot/etc. It was then decided that shoes should be prescribed based on the plantar pressure of each person. This reduction in pressure was calculated based on the comparison of a tennis shoe to the other shoe. This is not a good control. This study shows that running shoes with cushioning decrease peak pressure compared to tennis shoes.
Nigg (2000) concluded that the midsole of running shoes had a minimal effect on impact force peak external and internal. This indicates that cushioning does not alter impact forces in any significant way. How is this possible? It’s obvious that if you jump on concrete, the shoe surface will be softer. This question will be addressed in a moment.
The Impact Forces picture becomes cloudier
It’s not as easy as it sounds. Scott (1990), conducted an interesting study that examined peak loads at the possible injury sites for runners (Achilles and knee). All peak loads were observed during push off and mid-stance. This resulted in the important discovery that the impact force at heel contact had no effect on peak forces seen at chronic injury sites. It led to speculations that the impact force was not related to injury development.
The impact force concept is further complicated by the fact that soft surfaces have no protection against injury when compared to hard surfaces. This is why? This is due to something called muscle tuning and pre-activation, which we will discuss below.
Other studies support this finding. They show that people with low peak impacts are at the same risk of being injured as those who have high peak impact forces (Nigg 1997). Impact seems to be the driving force behind increased bone density.
This should be obvious to you as a trainer or coach. If the stimulus is small and there is sufficient recovery, the bone will respond by becoming more resistant.