However, long distance running only takes half of the time required to generate the reaction force during walking.
When the foot touches the ground, the main influence is the reaction force perpendicular to the ground.
front support stage; 2.
Therefore, proper pronation is beneficial to reduce the impact force, while excessive pronation may cause more torsion force on the ankle and increase the pressure on the knee and hip joints.
Even if you can’t accurately describe what a good running posture should be, when you see a good running posture, you can see that it is good at a glance, that is, on the basis of keeping your back upright, lean forward slightly, relax your shoulders, and relax your arms between your waist and chest.
Rear support stage, that is, the moment before the toe leaves the ground.
The movement cycle of running is the whole process from the moment when one foot touches the ground to the time when the same foot touches the ground again (also called multiple steps).
During long distance running, the reaction force absorbed by the body on the ground is 2.5~3 times of the body weight for each step, which is twice of the reaction force generated by the ground during walking.
The biomechanical characteristics of each long-distance runner’s “running” determine the economy of his running; The mechanical characteristics of running are not only closely related to the prevention of injuries, but also affect the performance of athletes to a large extent.
Post support stage: The post support stage is the second stage in the support stage to generate driving force, mainly through the use of energy stored in muscles and tendons.
This force can be directly transmitted to the limbs and impact the bones.
The difference between walking and running is that even jogging, the swing phase is longer than the support phase, and a running action cycle also includes two take-off phases, that is, the time period when both feet leave the ground respectively.
People usually divide one step in the movement cycle of running into two stages: the supporting stage, that is, the process of feet touching the ground; The swing phase is the process from the foot off the ground to the next touchdown.
So, when discussing the biomechanical mechanism during running, can we regard the human body as a running machine? Although the world’s best runners still behave so smoothly and easily when running at high speed, it seems that we can really regard the body that is always moving as a running machine.
This action is very important because when the limb swings with a joint as the axis, its center of gravity is much harder to approach the end than the joint..
The process from walking to running is the process of shortening the support stage and increasing the swing stage.
Because muscle strain is the result of muscle bearing force in unit time.
When the body’s center of gravity moves forward through the upper direction of the support leg, the knee and hip joints of the support leg begin to stretch (until it is pushed off the ground).
The so-called pronation is “foot valgus”, or when the pressure is excessive from the outside of the heel to the front and inside of the foot, “foot valgus” because of this strange angle of the ankle anatomical structure function, so that the tip of the foot pronates inward – the sole abducts outward – to promote the lower leg and knee joint to produce internal rotation.
Pronation is the main means for joints and muscles to cushion these impacts.
Support stage In order to better discuss this complex part of the running movement cycle – support stage, we divide it into three stages: 1.
Therefore, the action cycle of running consists of two parts, one step for each leg.
Front support stage: we start to discuss the action cycle of running from the moment when the foot touches the ground – the foot touches the ground.
Cushion stage, that is, the process of body weight passing over the feet; 3.
After pronation, the foot is in an eversion position (outside of the inner pronation foot), because when the swinging leg swings forward, the lower leg of the supporting leg rotates with the rotation of the hip joint.
When we see the term “biomechanics”, it is easy for us to imagine the human body as a machine.
About 80% of the athletes touch the ground with their heels or back soles first, which is called heel touching, and 20% of the athletes touch the ground with the middle of their feet, that is, with the outside of the middle of their feet.
Some of the absorbed energy is used to cushion the impact of external forces on the body, but most of the energy is stored as the driving force for the body to move forward.
Therefore, a runner with good “running economy” will consume less energy in training or competition at a specific speed.
Buffer stage: The buffer stage is the process from the foot touching the ground to the body’s center of gravity passing directly above the foot.
The arm swing is to balance the movement of the lower limbs, that is, when one foot is off the ground, his opposite arm begins to swing.
On the one hand, it is caused by the active contraction of thigh and hip muscles, and on the other hand, it is caused by the stretch reflex retraction after the elastic components are stretched.
A very important concept in running is “running economy”, that is, how much energy the runner needs to consume per unit time when maintaining a specific running speed.
Therefore, compared with walking, the reaction force generated by running is 4 times more likely to cause damage to relevant tissues than walking.
When walking, the time ratio between the support stage and the swing stage is about 3:2.
During the swing phase, after the foot is off the ground, the hamstring muscles contract to make the lower leg move towards the hips, and keep the knee joint at this angle until the weight is swung forward.
This pronation and calf muscle contraction lock the ankle joint and help generate power when the toe is off the ground.
The transition from the foot touching stage to the supporting stage is also a process of energy absorption.
The basic principle of running everyone knows how running is.
When the hip joint twists and pulls the swinging leg to swing forward, the knee joint is lifted and the upper body rotates in the opposite direction to maintain balance.
Usually, we use oxygen consumption rate to evaluate the level of energy metabolism, because it is the most convenient method to evaluate the speed of energy metabolism during aerobic exercise.
However, for most runners, sports injuries and the factors that hinder sports performance from reaching their maximum potential are closely related to the biomechanical mechanism of the body.