The injured runners have very high vertical impact speed, while the runners who have never been injured have relatively low vertical impact speed
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This study shows that the total impact force of both injured and non injured runners is almost the same when landing, but the index of vertical impact rate is different from impact force, which reflects the change speed of impact force, that is to say, the ground is extremely heavy, and the impact force has a short-term peak; or the landing is very light, and the impact force appears slowly and gently
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In the process of running, every time the foot touches the ground, it will inevitably form a huge impact on the ground
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Generally speaking, the time for feet to touch the ground during running is 1 / 4 ~ 1 / 3 second, and the difference between the two local styles is only 50 milliseconds
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Marathon athletes and professional runners mostly use the forefoot landing, so that the buffer is better and the landing sound is very light
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Two years later, Professor Davis divided the group of runners into two categories: 144 injured and 105 uninjured
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They really can hear the sound before they see them
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Professor Davis believes that all the vertical impact speed of non injured runners is low, and the landing is light, because they make full use of the muscles of ankle, knee and hip to cushion, while those injured runners, that is, those “stomping” runners (landing sound is relatively loud) are very stiff and lack of cushion
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The total force during landing is about twice of the body weight
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As for whether to land with the forefoot or the heel, it is not so important in itself
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In addition, Professor Davis made a more detailed classification of these runners, and further divided them into the runners who were seriously injured and needed clinical treatment and the runners who had never been injured in two years
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Therefore, Professor Davis believes that the weight of landing may be more important than the location of landing
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When the heel landing, the forefoot is easy to lack of cushion and slap the ground, so it is easy to have the problem of heavy footstep
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Professor Davis found that the most obvious difference between the two types of runners is that the vertical impact speed is very different
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Don’t be a “stomping” runner
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The Harvard study shows that a gentle landing can reduce the risk of running injury
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The steeper the diagonal line is, the sharper the impact force increases
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Davis followed the runners for two years to find out which of them had been injured two years later? Which ones have never been hurt? How do the uninjured runners do it? Davis and his colleagues recruited 249 female amateur runners (women are more prone to running injuries than men themselves), who ran at least 32 kilometers a week and landed on their heels
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Third, the runner with heel landing adopts heel landing, and the landing place should be closer to the center of gravity in order to effectively cushion
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The figure shows the change of ground reaction force during landing
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Even though the time difference is so short, if repeated thousands of times, small differences can add up and eventually lead to running injuries, says Professor Davis
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The study found that the best step frequency is between 180-190 steps per minute, when the landing sound is softer
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In Professor Davis’s study, female volunteers who had never been injured touched the ground very gently
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They ran like floating on the water
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Finishing: no injury running law, authorized by people’s Posts and Telecommunications Publishing House“
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A heavy runner can still touch the ground lightly, and a light runner can also touch the ground heavily
Second, the runners with poor muscle strength generally have poor muscle buffering ability, especially the weak strength of some very important muscle groups in the ankle joint
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The vertical impact speed is hard to detect for ordinary runners, but if it is changed to touchdown time, the runners can understand it
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The diagonal line represents the change speed of impact force during landing
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However, there is no necessary relationship between this and weight
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The slower the diagonal line is, the softer the impact force increases
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They carefully compared the gait biomechanical characteristics of these two types of runners
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The reason is that through the arch, Achilles tendon and calf muscle instead of the heel to absorb the impact force, but the front foot to the ground for ankle leg strength is very high
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However, your running footsteps are also very loud, which needs attention, because this may be the cause of your injury! Harvard Medical School and the national running injury research center of Spaulding Hospital Affiliated to Harvard Medical School conducted a study and published the research results in the famous “Harvard Communique”: those runners with light landing seldom suffer from injury, while those with heavy landing and very loud footsteps are very vulnerable to injury
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But for the vast majority of runners, they mostly use heel landing, so Davis only studied heel landing runners
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There seems to be little difference in the number of runners between the two groups
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At the beginning of the study, the volunteers were asked to perform gait tests on a dynamometer and record the impact of each step
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Explain briefly what the vertical impact rate is
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The strength and stability of the ankle are usually ignored by the runners
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So runners may as well take off their earphones and listen to your running voice when running
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During this period, the volunteers were asked to complete an online questionnaire once a month to record their injuries
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It lasted for two years
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The most important gait feature data is vertical impact velocity
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They run like a tank, and even can hear it every ten meters
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Many friends say that when they run, their feet fall to the ground with too much noise, and their feet are as heavy as cattle
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At this time, the ground will form an equal and opposite force, which is known as the ground reaction
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Heavy touchdown is often accompanied by a long touchdown time, while light touchdown has a short touchdown time
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According to the preliminary analysis of Professor Irene Davies of Harvard University, she divides the loud footwork during running into three main reasons: first, the heavier runners, and the heavier people will suffer more impact when their feet are lifted up and down during running, and the external performance of this impact is that the heavy footwork makes a lot of noise when they land
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