Light as plume to run without injury: light running skills
Running is a popular form of exercise, but seemingly simple running also seems to have a very high risk of injury. The data shows that 60-70% of runners have had injuries that caused their running to be interrupted. The injury rate in the crowd is as high as 90%. Therefore, how to run without injury is a major problem for all runners.
First, the main sources of running vulnerable to crash landing force
When running on the ground, the weight plus inertia, the human body will produce 2-3 times the impact force of the ground, according to Newton's third law, the force must have a reaction force, then the ground will give the body the size of the opposite direction of the GRF ( Ground Reaction Force (GRF). If it is an occasional run, such impact is basically negligible, but long-term running coupled with poor running, lack of strength, unreasonable, excessive, and continuous ground reaction force is likely to negatively affect the skeletal joints Causes damage.
Second, lightness can be without injury
Then, how can we reduce the impact on the human body when landing? It's simple and it buffers forces effectively. For example, when we jump up and down from a height, if your lower limb joints are fully straightened and the entire sole of the foot is directly on the ground, then it is conceivable that you will be accompanied by a loud bang and a great impact. If you fully flex the three joints of your lower extremities, hips, knees, and knees with your forefoot, you will fall silently like a cat, thus dissipating the ground reaction force in a full cushion.
Marathon runners run much more than the mass runners, but why are they not hurt because of the constant impact on the human body? The fundamental reason is that their superb running skills and good muscle strength ensure that they can land lightly. No injuries run.
Third, lightness is both a manifestation of technology and the ability to reflect
Lightweight is the external performance of good running ability. So how can we achieve light running? You need to do the following two things: First, form a reasonable running position, especially if you are on the ground. Second, learn how to use muscle strength to effectively buffer. This ability can be improved through training.
Fourth, what is considered reasonable landing
If the forefoot lands, the buffer is better
From ground heel to foot, the ground reaction force changes during the process of ground clearance. Obviously, at the beginning of landing, there is a sharp increase in ground reaction force peak, which is not only great, but also very fast. In other words, if the heel is used directly on the ground, it cannot be effectively cushioned by the ankle. At the moment of landing, the ankle and the knee joint above the heel are subjected to a large peak stress.
When the forefoot landed, the ground reaction peak disappeared because we changed the way we landed and absorbed the impact through the arch, the Achilles tendon, and the calf muscle instead of the heel. At the same time, we also need to notice that the sloping line has become moderate, which also shows that the ground reaction force is effectively buffered.
In other words, when using the forefoot, because the place is in front of the sole of the foot, the moment the landing heel is lifted slightly, and then fall, it is such a tiny short-term tiny ankle movement, you can greatly increase the landing time The cushioning reduces the impact of the ground on the human body
In terms of internal forces (main force is mainly muscle contraction force), the forefoot greatly increases the tension of the soft tissue such as the muscles of the calf, the plantar and other parts, because only the tension of these parts can buffer the ground force, which is why some runners Once the forefoot of the foot is attempted, it is felt that the calf sole is very tired, and even causes an important cause of calf bone stress syndrome, Achilles tendinitis, plantar fasciitis and other problems. In other words, if you want to use the forefoot, you must strengthen your calf muscle strength training.
Although professional marathon runners are more likely to use their forefoot grounds, studies have shown that 95% of the mass runners use the heel to land. Does that mean that the heel striker will inevitably receive greater impact? It's not always true. Increasing the buffer can also be achieved in another way - the position of the ground. A reasonable landing position is: the location of the landing is slightly ahead of the projection of the center of gravity, and the knee remains curved as it touches the ground.
Runners should try their best to avoid the way the knee joints are locked and locked at the same time as the following figure shows. This kind of running method is very harmful to the joints of the lower limbs. Why do you say that? At this point, the knee joint is fully extended and locked. In the moment when the heel touches the ground, it can be imagined that the ground reaction force will reach the knee due to lack of cushioning. This is also the reason why the knee injury becomes the runner's number one injury.
If the location is close to the center of gravity, the knee joint maintains moderate flexion, and the bent leg helps to disperse and dissipate impact from the ground. On the other hand, it can bring more cushion by actively pressing down the knee when landing. Achieving the location close to the center of gravity is mainly achieved by appropriately reducing the stride length and increasing the stride frequency (close to or up to 180 steps/minute).
Muscle training to improve ground cushioning - Centrifuge training
First of all, we should share with everyone the name of science, concentric contraction (concentric contraction) and eccentric contraction (eccentric contraction), both of which are the most common ways of muscle work. In simple terms, centripetal contraction refers to the contraction of muscles and the production of tension. At the same time, the muscles are shortened. For example, the lifting of the heel during lifting movements is the process of concentric contraction of the calf muscles.
When the squatting force is exerted, the muscles contract to concentrically against the gravity, allowing the body to vacate, and the muscles are centrifugally contracted when landing, allowing the feet to softly touch the ground instead of hitting the ground directly. When the runner runs muscle strength training, the main emphasis is on the centripetal contraction process, while the eccentric contraction is often overlooked. In fact, the eccentric exercise has a good effect on improving muscle strength and promoting rehabilitation of injuries. It has already been mentioned that the occurrence of running pain is mainly related to the lack of floor buffer in the ground, and the centrifugal contraction is the main working form of the muscle in the brake buffer phase. The lack of muscle centrifugal force easily leads to insufficient cushioning when running and landing, resulting in greater impact on the joints, which may cause damage. Therefore, it is of great significance to prevent running injury by increasing the cushioning ability of the ground through centrifugal training.