There has been a lot of mixed advice in the past, and even the present about how runners should run. This may not seem like a big issue, but the way your foot strikes the ground when you run can have a big impact on running performance and injury rates. Typically, there are three main ways people land when running: forefoot strike, midfoot strike and heel strike.
Looking at it from a Natural Perspective
Think about the African runners: the Kenyans, Ethiopians, Somalians – any African country really. You hear stories about them running barefoot to school and back.
Now, how do they run when they run barefoot? How do they strike the ground?
The answer is, with their forefoot. The part of your foot just behind your toes. One of the main reasons for this is, it is painful for them to land of their heel so the feedback gained from the nerves within their feet forces them to adopt a natural forefoot running style.
This is also the reason why shoes wore by track runners have spikes on the front of the shoe – to encourage you to land on your toes.
Generally, those who heel strike tend to overstride slightly and lean back when they run. This is inefficient as you are placing your centre of gravity far from your centre of body mass which leads to a large waste of energy which could be used to run faster.
Those who forefoot strike or midfoot strike are more likely to land with their foot directly underneath them, with their centre of gravity closer to their centre of mass, leading to less energy wasted and a more efficient running style.
Those who want to shorten their stride so that they can land more efficiently, by placing their foot closer to their centre of mass (under your hips), can do so by using shoes with a lesser incline from toe to heel and focusing on shortening their stride.
Ground Reaction Forces and Force Distribution
Another interesting point is that research done Dr Daniel Lieberman from Harvard, has shown heel striking to generate a large impact transient. An impact transient is a distinct impact generated at the beginning of the ground reaction force coming up through your body after you land. Here is are two videos showing the impact forces generated from heel striking and forefoot striking. The initial peak generated heel striking is the impact transient. As the forefoot runner has a smoother transition with no initial peak, there is no impact transient.
The magnitude of the impact transient during heel striking was 3 times body mass, much greater than forefoot striking. This is due to the instantaneous loading of the ground reaction force on the body during heel striking. Now, the heavier you are, the greater this impact transient will be which can increase your risk of injury as your body will have to work hard to mitigate the stress caused by the initial impact.
Although it may not seem like it, the collision with the foot and the ground during forefoot striking produces a slow rise in force with no distinct impact transient. This can generate impact forces that are seven times less than runners who dominantly heel strike, despite rates of loading being more or less equal for heel strikers and forefoot runners.
Cushioning in shoes has been shown to help reduce the impact transient caused by heel striking.
Midfoot strikes are somewhere between heel striking and forefoot striking, where the heel and forefoot hit the ground simultaneously. Because of this, impact forces can be distributed more evenly around the whole foot, but this depends on where the centre of the pressure of impact is and how stiff the ankle and knee are upon landing. This means that impact transients similar to heel striking can be generated, but also have the impact forces distributed more evenly reducing stress on the body. Midfoot strikers who can land softly will not generate as great an impact transient.
The more you run, the more likely you are to get injured due to the cumulative stress being placed on your body. In addition, you are likely to get less rest to allow your muscle and tissues to repair. A study has shown that in endurance runners, heel strikers are approximately twice as likely to get injured as forefoot strikers with overuse injuries.
Reasons for this are likely all linked to the impact transient in that the initial impact causes the tissues to vibrate, causing muscle fibres to swell, impairing nerve impulse conduction, causing the body to move less efficiently.
There is also an idea that because of the impact transient and the ‘dip’ seen on the distribution of ground reaction force on the graph shown above that when heel striking, you are ‘braking’. It does seem to appear that the impact transient is the main cause linking heel striking to higher rates of injury.
Now whilst this post may show heel striking to be ineffective, there are many elite runners who do heel strike, but I am certain if they adopted a ‘forefoot’ strike approach they would be more economical in their running which would translate to faster running times, as well as reduced injury rates since the stress on your body, will be greatly reduced.
If you are trying to change from heel striking to midfoot or forefoot striking, be careful and take it easy as changing your foot strike can activate different muscles you are not used to using such as the gastrocnemius (back calf muscle), and if you overdo it, it can quickly lead to injury.
If you do continue to heel strike, I would suggest building up mileage and intensity gradually and focusing on landing with your foot just below your hips as this will help to reduce stress on muscle tissues, bones and tendons by placing your centre of gravity closer to your centre of mass, as overstriding is also a factor which has been shown to cause injury and it may be the case that most heel strikers overstride which is why their injury rates are higher.
Whilst I do tend to heel strike occasionally, I try to focus on maintaining a forefoot running style when I run.
I hope this post was insightful. Let me know how you strike the ground down below and if you’ll be doing anything to change that!