During the experiment, the camera should be placed half way along the runway and far enough away from the runner, so that the runner can capture the image of the runner’s whole body when passing by.
After the two lines are drawn, a complete angle is formed.
Measure the angle.
The measurement FAT starts from the point where the foot first touches the ground (i.e.
Confirm posture.
Open the video using the video application and play it frame by frame until you find a picture of a leg swinging forward to the maximum amplitude (either right or left leg).
In fact, the correct running mode is very simple and easy to learn, and it is applicable to almost all runners.
the moment when SAT is measured), and draws a straight line along the foot, from the bottom of the heel to the bottom of the toe.
Check the video for 3 times to ensure that 2~3 times of touchdown actions are completely recorded in each video.
If you are a long-distance runner, the best SAT is 5-7 degrees; If you are a short runner, the best SAT is 6-7 degrees.
The angle formed by these two lines is FAT.
The optimal ROS/MSA value is 0.7~0.75.
3.
Measure the angle of motion (ROS) of the lower leg and foot from the point farthest from the body to the first touch of the foot or the distance back from MSA before the foot touches the ground.
The value of ROS/MSA is calculated by dividing ROS by MSA.
5.
Once the exact moment when the foot touches the ground is found, draw a line from the knee joint through the foot to the ground.
The data of a runner’s right leg and left leg may be very different, but this is normal..
Draw a second line from the bottom of the first line, extending straight and parallel to the ground.
This line can end slightly below the foot, but make sure it passes straight through the knee and foot.
Although a small ROS/MSA value will result in very small kinetic energy transferred to the ground, an excessive value, although rare, may also put the legs at a disadvantage from the perspective of generating the best propulsion force.
Bad posture will produce two discontinuous lines.
The faster the speed, the greater the MSA.
6.
The MSA measurement starts from the first jogging video taken.
Picture from 123rf.com Cn How can you tell if your running mode is correct? The six key elements of the running pattern can be evaluated through video analysis.
MSA actually increases with the running speed.
Click the blue text above and remember to follow us! The traditional view is that runners only need to run naturally like breathing, without too much thinking, planning or practicing coordinated gait.
The two lines will intersect under the foot and form an angle.
In a good posture, the line passing through the center of the hip, the center of the chest and the center of the head can be connected into a straight line, and the whole body is slightly tilted forward.
Picture from 123rf.com Cn runners run across the shooting position in a very natural way from the end of the 60 meter track after a full warm-up.
Runners should move from left to right (or from right to left), so as to take a side view of runners when running.
If the ankle joint bends back when the foot touches the ground for the first time, FAT is positive; If the ankle plantar flexion occurs at the time of touchdown, FAT is negative.
Evaluation Posture To evaluate posture, you should select a moment in the middle of the runner’s support in the video, locate three points on the runner’s body: the center of the hip, the center of the chest, and the center of the head.
Draw a second line from the bottom of the first line, extending straight and parallel to the ground.
Then draw a straight line from the hip to the center of the chest, and then draw a straight line from the chest to the center of the head.
Compared with the line from hip to chest, the line from chest to skull leans forward more, which will damage the level of sports performance.
Then start from the contact point (heel or forefoot) and draw a line parallel to the ground.
By watching the video shot, especially analyzing the slow shot, you can determine the posture and four key elements: MSA, ROS, SAT and FAT.
Compare 3 videos and measure the above angles of the left leg and the right leg respectively in 3 videos, and record all values in the table.
This helps the body move forward during the gait support phase, not just upward.
1.
4.
Subtract 90 degrees from the angle value to get the SAT.
Video analysis requires smart phones or camera equipment with video function, as long as the camera speed can reach 240 frames per second.
Determine the foot angle (FAT) at the first touchdown.
2.
Calculate the value of ROS and ROS/MSA.
In this way, runners can improve their running mode in an objective and quantitative way.
ROS is the difference between MSA and SAT (ROS=MSA-SAT).
Determine the ratio of ROS to MSA (ROS/MSA).
This is a very critical data.
Subtract 90 degrees from the measured angle to get the MSA.
Confirm the distance that the leg moves to the front of the body in the gait swing phase, and calculate the maximum tibia angle (MSA).
Measure the tibia contact angle (SAT).
Using the frame showing the maximum forward swing, draw a straight line down the lower leg through the foot starting from the center of the runner’s knee joint.
To evaluate the running mode, it is necessary to find a place where the analyzed runners can run about 60 meters in a free way on the flat ground.
Repeat the run twice, once at a moderate pace and once at a faster pace.
Measure the SAT and continue to drag the video playback progress bar forward frame by frame until you find the picture of the first foot touching the ground.
The result of this concept is that many runners are using the wrong running mode, which obviously damages the performance level and running efficiency, and increases the risk of injury.