ABDOMINAL CORE STRENGTH TRAINING AND BODY STABILITY IN TAE KWON DO ATHLETES

ABSTRACT Introduction: Abdominal core strength is one of the main factors controlling body balance, helping to efficiently apply body kinetic energy to the movements of Tae Kwon Do martial arts. Objective: Explore the effects of abdominal core strength training on postural stability in Tae Kwon Do athletes. Methods: Forty Tae Kwon Do competitors were randomly selected and divided into experimental and control groups. The control group was subjected to the club's regular exercise program, while the experimental group added three months of stabilization exercise to the regular exercise program. The changes in the experiment on each index were analyzed statistically. Results: After 3 months of postural balance training, Tae Kwon Do athletes' center of gravity stability was improved. The results showed significant improvement in squatting, stretching, thoracic girdle flexibility, balance ball flexion, and ipsilateral hand extension (P<0.05). Conclusion: Abdominal core strength training can improve core muscle group strength in taekwondo athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.


INTRODUCTION
Exercises that strengthen the quality of strength can promote the development of taekwondo athletes.At present, the conventional physical training cannot meet the requirements of the comprehensive quality of Taekwondo players under the current rules, and the exercise of core strength is a brand-new way of strength training.Its role in competitive sports has been generally accepted.The midline horizontal technique is the leading technical indicator in Taekwondo competitions.The results show that among the various leg techniques, the more times the lateral midline technique is used, the higher the score when attacking. 1 The results showed that during the competition, the use of the intermediate level of the horizontal leg achieved a score of 57.1%.Therefore, technically, the application and score of the mid-section lateral technique are higher than other leg techniques.In recent years, core stability training has been the focus of scholars at home and abroad, and its training methods are also widely used in competitive sports. 2Therefore, this paper investigates and analyzes the effect of the middle lateral leg speed on the stable center of gravity of young Taekwondo players.

METHOD General information
This paper takes 40 taekwondo players as a research sample.In this paper, 40 contestants were divided into experimental and control groups.There were no significant differences among the athletes regarding age, height, weight, the median number of kicks in the 30s, and years of training.(Table 1) The control group was performed according to the regular club exercise program, and the experimental group was added three months of core stabilization exercise to the regular exercise program. 3In this paper, the changes in each test index before and after the test are statistically analyzed.
The training period for the promotion period is more than one month.This session focuses on working out in unstable situations for young athletes, doing less weight training in unstable situations, and strengthening and enhancing the balance and control of their muscle groups. 5Under normal circumstances, follow the physical exercises formulated by the coaches of the Taekwondo Club, such as dynamic stretching, flexibility, rope ladders, kicking targets, signs, etc.

The mathematical expression of attitude and discussion on solving methods
The posture data of the carrier in any coordinate system can be expressed by the quaternion method, the Euler angle method, and the azimuth cosine method.Quaternion theory is the most important one in quaternion theory. 6It uses four different components to represent the position of the rigid body in the coordinate system.The quaternion number G can be expressed by the formula (1).(1) G g g i g j g k = + + + (1) Each actual number in the equation represents g 0 , g 1 , g 2 , g 3 , respectively.i, j, k all represent an imaginary element vector, which are perpendicular to each other and conform to equation ( 2). (2) , can express the size of a quaternion value. (3)

G g g g g = + + +
In this paper, the quaternion number is used to represent the position in the coordinate system, and its physical meaning can be regarded as the signal of rotation if a rigid object is in its starting coordinate system OX n Y n Z n .The coordinate system OX b Y b Z b is obtained after rotating around R  by a certain angle ∂.On this basis, the angles of roll θ and inclination ψ have not changed.Only the inclination φ has changed. 7This is due to the rotation of the race around axis X. Quaternion numbers can be expressed by Equation 4. (4)  [ ] Therefore, the direction cosine R X , R Y , R Z of the vector R  in Eq. ( 4) in this coordinate system is used to express respectively. 8If any two-four elements g and h satisfy h = [h 0 h 1 h 2 h 3 ], g = [g 0 g 1 g 2 g 3 ] respectively, three basic mathematical laws of a quaternion can be obtained. (5)

Training plan
This test is based on the number of kicks in a specific time limit to assess the level.According to the "stable center of gravity" concept, it should follow the principle of gradual increase and improvement. 4Athletes practice according to the principle of gradual increase, 15-45 seconds each time, 10-20 times each time, and the interval is 1:2.One of the essential tasks in core stability training is to keep young athletes unsteady and unbalanced.This promotes the full use of the muscle groups in their central body.According to the principle of gradual development from simple to complex and from less to more, this paper divides the learning process of the whole system into three stages: adaptation, stabilization, and improvement.
More than a month of adaptive training.This research aims to let young trainees feel the balance of muscle strength and control of the body, enhance the stability of their movements, and enhance their control and balance of the body.
More than a month of regular training.During this period, the deep muscles in the center can be fully mobilized, and the balance of young athletes in the middle transverse leg can be enhanced.

ETHICAL COMPLIANCE
Research experiments conducted in this article with animals or humans were approved by the Ethical Committee and responsible authorities of School of Physical Education(Mailu Campus)Jiangxi University of Finance and Economics and Jiangxi Open University following all guidelines, regulations, legal, and ethical standards as required for humans or animals.

Mathematical Statistical Analysis
This paper uses SPSS and Excel software to analyze, count, and draw the collected data to obtain relevant research results and conclusions.

The effect of the mid-position horizontal kick on the stability of the body's center of gravity
After an adjustment period of more than one month, the experimental group improved the average horizontal kick frequency both before the test and within 30 seconds after the test.(Table 2) The lateral kicking time between the experimental groups in different adaptation periods was statistically significant within 30 seconds (P<0.05).The frequency of the median lateral leg in the experimental group increased significantly within 30 seconds, while there was no significant difference compared with the control group within 30 seconds (P>0.05).
During the acclimation period, the median number of transverse legs in the experimental group at 30 seconds increased by 30 seconds compared with the control group.(Table 3) The lateral kick time between the experimental and control groups in different periods was not statistically significant within 30 seconds (P<0.05).After more than one month of the center of the gravity stabilization period, the 30-s median frequency of lateral leg movements in the experimental group improved.Still, the difference was insignificant compared with that before the experiment (P>0.05).Therefore, 30-second exercises with a stable center of gravity are not effective in increasing the number of lateral legs.

The effect of stability on the median transverse leg speed
During the stabilization period, subjects significantly increased the frequency of lateral kicks before and within 30 seconds after the test.(Table 4) The number of lateral kicks within 30 seconds was statistically significant during the stability period compared with the control group (P<0.05).In the control group, the frequency of median kicks increased significantly within 30 seconds (P>0.05). 9uring the stability period, the average number of kicks in the experimental group within 30 seconds was significantly improved compared with the control group.During the stability period, the number of lateral kicks in the experimental and control groups within 30 seconds was statistically significant (P<0.05).

The role of the median lateral leg movement in core stability training
The frequency of lateral kicks in the experimental group increased significantly 30 seconds after the test.(Table 5) During the boosting period, the number of horizontal kicks within 30 seconds of the experimenters was statistically significant compared with the control group (P<0.05).The frequency of median kicks in the experimental group increased significantly within 30 seconds, while there was no significant difference in the number of lateral kicks between the two groups within 30 seconds of the increase period (P>0.05).
During the improvement period, the average level of kicks in both the experimental group and the control group for 30 s was significantly improved.(Table 6) (P<0.05).

DISCUSSION
Solid support is critical for taekwondo players.Because it allows players to quickly adapt to the needs of the action, at the same time, a substantial body center of gravity can effectively control the body's acceleration, deceleration, and stability to enhance the body's balance and reduce sports injuries.(1) Strengthen the stability of the central area.It stabilizes the center of gravity and maintains balance.It plays an essential role in the coordination and coordination of the upper and lower legs.Athletes need to mobilize the core muscles in advance so that the center of gravity of the body is fully prepared to support the strength of the limbs.(2) Exercise the muscles to reduce the exercise's energy consumption and enhance the exercise' s balance.In daily physical training, we also noticed that many coaches only emphasize the exercise of large muscle groups while ignoring small muscles, not only in taekwondo.One of the most critical aspects of core strength training is to get many muscles working together during the exercise. 10And this is also to mobilize more muscles to complete this action.For example, shoulder pain will occur after a shoulder injury, and heavier upper body training is unsuitable for the body.(3) Core strength training has an excellent preventive effect on joint and muscle damage.The steady development of the core position of the body can promote the balanced development of muscle strength.This can reduce the body' s ability to adapt to unique movements caused by particular long-term exercise.For example, the tension and tension of the shoulder and shoulder muscles are unbalanced due to long strokes.This leads to joint instability or dislocation of the joint, which leads to joint damage.In addition, pain can also cause the muscles to lose strength and thus reduce strength.It is impossible to eliminate the pain fundamentally if only relying on medical methods to treat it.Athletes can only take a comprehensive approach to prevention and prevention from multiple aspects.

CONCLUSION
The results showed that the center stabilization exercise significantly promoted the speed of the middle lateral leg of the young taekwondo

Table 1 .
Basic data of 30 test contestants.

Table 2 .
Average horizontal kicks before the test and 30 seconds before the test.

Table 3 .
Horizontal comparison of the number of horizontal kicks between the experimental group and the control group within 30 seconds.

Table 4 .
Average number of horizontal kicks before and 30 seconds after the test.

Table 5 .
Increased frequency of lateral kicks between test groups within 30 seconds before and after the test.

Table 6 .
Level comparison between experimental and control groups in 30 seconds.