DO WE NEED TO PUSH OFF IN RUNNING?
From the beginning of the running boom in the early 70s we know that in running together with the pleasure of it we get a lot of problems with injuries. Runner's World magazine survey stated in 1977 that 2 from every 3 runners are injured every year. And this problem remains unsolved even now, only today it's happening on a larger scale, because the number of people running increased from 15 million in 70-ies to 33 million at the beginning of the 21st century. No matter how much the design and quality of sport shoes have improved, how much higher the education of athletes and coaches have become, and how incomparably better the level of medicine have become, too, the number of injuries is still the same. A reasonable question arises: What are we missing here?
Running has become the most injury prone sport event despite its established position as a simple, natural and accessible for all exercise, based on a common sense or conventional wisdom approach. The "philosophy" of running technique is compressed to a very simple formula: put one foot in front of the other, and push your body forward by unbending the support leg in the hip, knee and ankle joints. The key phrases here are: the "push off" and "toe off", which symbolize the running technique perfection. The push off became a corner stone of the existing paradigm of running, which has never been revised and never attempted to be changed.
One might ask what is wrong with this picture? If everything goes according to Newton's laws of mechanics, why do we even bother to ask? Is there a really good reason behind it? Do we need to change anything there? As we know, humans are very conservative by nature, resisting any changes, and to go against this nature we should have a very serious reason.
Our reason is as follows. Our Pose Method® introduces a new paradigm of running technique, which offers a more efficient and more economical model of movement, a better logic for understanding this movement and teaching it
. All this can help us to improve our speed and performance and avoid injuries.
One of the first requirements in this new paradigm of running is not to push off, which coordinates with several others in running technique.
Let's look at a list of forces interacting in running in order to move the body forward. There are four major forces, which have an influence on the body's forward movement during the time of support: gravity, muscle elasticity, ground reaction and muscle contraction.
The last one is the voluntary muscle activity, when they are shortened or contracted by the nervous system signal from the brain, which requires a breakdown of chemical substances - ATP in order to produce the energy for this contraction.
Ground reaction is the force which reflects all forces coming from the body and applied to the ground.
Muscle elasticity is, in a wider sense, the elastic property of muscles, tendons and ligaments, or the ability to restore the previous length after being stretched by some external force or forces. It's well known as a stretch-shortening reflex, rebounding effect, etc. In 1964, Italian scientists G. Cavagna, F. P. Saibene and R. Margaria found that muscle work in such regime in running allows one to increase efficiency of his movement up to 50%, which is twice more then in any another mechanical system. Only one thing they forgot - they didn't tell us how to use it.
Gravity is the constant, nonstop acting force, which creates gravitational acceleration 9.8m/sec2 to any body mass going down towards the Earth. The question is how to learn to use gravity more efficiently by our muscle work or activity. Wait a minute, but we need to move forward, not down. You would think that there should some way to redirect the body movement from downward to forward, and then repeat it again and again, after landing in each stride.
Certainly, it is so, and this is the function of the rest of the forces - to assist gravity in pulling the body along the way in the horizontal direction, and this is how all the forces could be harmonically integrated in running movement.
The rebounding effect coming from muscle elasticity, when we strike the ground, allows our body to move up in the air just enough to be able to change the support from one leg to the other, while the general center of mass flies in the horizontal direction proportionally to the velocity of the body moving in the same direction. The vertical oscillation of the GCM, as it is shown in a science research by R. Margaria (1976), has a constant value independent of the speed and length of the distance. In running the center of gravity of the body is never lifted above the position it has been when the subject is standing in the erect position, i.e. the highest position for falling. This height, as shown by some different sources, has a small range of 4-6 centimeters between the best runners (sprinters and marathoners). In other words, the general center of mass of the body travels evenly in the horizontal direction.
Read a complete article in Dr.Romanov's Training Essays Vol.I
- a collection of short articles written by Dr.Romanov on various training, exercise and rehabilitation topics.