Introduction
Due to technological advances, sport is an individual need and a social necessity in today’s societies. It is a factor used to develop physical and mental abilities and eliminate physical poverty [1] Therefore, a proper and broad context is necessary for a sport to be pervasive due to its characteristics and to grow and develop so that winning the championship and success in it will cause national pride. Meanwhile, wrestling with its features and charms has taken root in all parts of the world and has attracted many enthusiasts, given that wrestling is known as the first sport in the country and is very popular. Every year, many teenagers and young people are eager to wrestle, turn to this sport [2].
As a result, when the more athletes in a sport, the number of sports injuries will be higher than in other sports. On the other hand, because wrestling takes place at a level unfamiliar to the body, such as the mat (soft, with a slight depression while standing), it requires more balance than other sports [3]. Balance is one of the main components of most daily activities and a significant factor for athletes’ athletic performance. To the extent that researchers believe, balance is an essential factor in sports [4].
In the meantime, lower limb abnormalities can also play a significant role in the balance of athletes and cause problems in walking, running, and basic motor skills [6]. For example, a flat foot is a complication in which the height of the medial longitudinal arch of the foot is lost or reduced. Flat feet can be flexible and rigid. People with flat feet suffer from many biomechanical inefficiencies, abnormal gait, and premature fatigue. Any decrease in producing energy during exercise is called performance-induced muscle fatigue [10].
Exercise-induced fatigue can affect postural control in people with plantar arch deformities and increase the risk of injury and decreased athletic performance [11]. There seems to be a close relationship between physical fatigue and balance with the mediating role of flat feet, which can be problematic for all athletes, including wrestlers. Therefore, in this regard, the present study investigated the effect of an exhaustive exercise session on the static balance of freestyle wrestlers with flat feet.
Materials and Methods
The present study is a quasi-experimental study conducted by field experiment with an experimental group with applied and developmental goals. The statistical population of this study is freestyle wrestlers of North Khorasan province, from which 15 qualified people were purposefully and accessibly selected and participated in this study voluntarily. After completing a health questionnaire and consent form, subjects entered the study to participate in the research and obtain information about cooperation’s nature.
Individuals performed the exhaustive exercise protocol program according to the scientific principles of exercising and under control. The static balance test was measured before and after (pre-test/post-test) the exercising protocol. The stork test (standing on one leg) had used to assess static balance.
Descriptive-statistical methods in the form of indicators were used to analyze the data. In analyzes such as Mean±SD, SPSS software v. 22 was used. Tables related to descriptive statistics of individual variables of research subjects, including weight, height, age, and body mass index (BMI), were drawn. In inferential statistics, the Shapiro-Wilk test was used to check the normality of data distribution. The dependent t-test was used to examine intragroup changes (a statistically significant level of P≤0.05 was considered).
Results
The results of changes in the means in Table 1 show that the number of static balance changes in the pre-test/post-test stages differed.


In the first stage, when no exercise had been performed on the subjects, the rate of the studied indicators was high, and in the second stage, after completing the exhaustive training, this amount decreased.
According to the research results (results obtained from tests and tests), it had found that there is a significant relationship between demographic characteristics and the static balance of wrestlers with flat feet (P≤0.05). Also, the dependent t-test results in Table 1 showed that the changes within the group during the pre-test and post-test stages of static balance were significant (P≤0.05).
Discussion
It had concluded from this study results wrestlers with flat feet after performing exhaustive exercises their balance level was statically lower than before exercising. Therefore, it had said that flat feet deformity reduces the performance and balance of wrestlers’ balance skills. Athletes with flat feet, to prevent premature fatigue and improve their balance, in addition to endurance and balance exercises, should also pay special attention to corrective exercises in this field.

Ethical Considerations
Compliance with ethical guidelines
In this study, all tests were performed based on valid scientific tests and in the presence of the head of the North Khorasan Province Wrestling Board and two instructors; All subjects were given a consent form to participate in the study, which after completing it and obtaining information about the nature and manner of cooperation, entered the study and all subjects participated in the study completely voluntarily. The subjects were also assured that In case of any problem or dissatisfaction at any stage of the research with prior coordination, they are allowed to leave the research.

Funding
All stages of this research have been done at the personal expense of the authors.

Authors' contributions
Conceptualization, validation, and project supervision and management: Mehdi Sabbagh Langroudi and Rasoul Nazari; Methodology: Rasool Nazari; Analysis, research, sources, drafting, editing and finalization of writing, visualization and financing: Ali Roshandel Hesari.

Conflicts of interest
The authors declared no conflict of interest.

Acknowledgements
The Honorable President of the North Khorasan Province Wrestling Board and all the wrestlers who accompanied our project until the end of the project are also thanked and appreciated, as well as the efforts of my guides and advice. It is possible to help my servant completing my thesis.


 
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