Investigation of Static and Dynamic Balance in School Basketball Players with a History of Ankle Injury

* Corresponding Author: Ali Roshandel Hesari, MSc. Address: Department of Sport Pathology and Corrective Exercises, Faculty of Physical Education and Sport Sciences, Isfahan Branch, Islamic Azad University of Isfahan, Isfahan, Iran. Tel: +98 (915) 3864051 E-mail: ali.roshandel1992@yahoo.com 1. Department of Sport Pathology and Corrective Exercises, Faculty of Physical Education and Sport Sciences, Islamic Branch Islamic Azad University of Isfahan, Isfahan, Iran. 2. Department of Sport Physiology Practical, Faculty of Physical Education and Sport Sciences, Bojnourd Branch, Islamic Azad University, Bojnourd, Iran. *Ali Roshandel Hesari1 , Amin Roshandel Hesari2


Introduction
espite all the benefits of consistent physical activity, the risk of injury --especially in competitive and championship activities -is undeniable. No matter how favorable the sports environment's safety conditions and the athlete's physical condition are, there is still the possibility of injury in this type of activity [1]. Basketball is one of D the most popular team games worldwide, and the number of fans of this sport is growing day by day [3]. Various studies have proved that the prevalence and risk of injury in basketball are very high [4]. During sports competitions, sudden interactions with the body push the body's center of gravity off the base of support. To avoid falling and losing balance, the center of gravity must be re-entered into the base of support by adjusting posture [6].
Lower limb injuries play a role in a person's imbalance and can cause walking, running, and necessary motor skills. The consequences of such injuries may last a lifetime, as lower limb injuries (ankles and Knees) may increase the risk of developing osteoarthritis later in life [7]. It is necessary to identify the variables that affect postural control and play a role in the rate of lower limb injuries, and the need for further research in this field is felt. That is why this study was performed under the title "Investigation of Static and Dynamic Balance in School Basketball Players with a History of Ankle Injury".

Methods
This study was a quasi-experimental and post-event study. The statistical population was all primary school students in one of the non-governmental boys' schools in Bojnurd city in 2018. The total number of students in this school was 283, of which a total of 76 were basketball players. Among these athletes, 18 had ankle injuries selected by convenience sampling and volunteered for the study. Eighteen other students without ankle injuries were selected for the control group. Subjects then participated in an orientation class related to this research. In this class, the necessary explanations were given about the study's objectives and its implementation method. Finally, the subjects were given a parental consent form to participate in the research.
To assess lower limb injuries, athletes' injury report collection form was used. This form, developed by the researcher, included information about: individual characteristics (age, height, weight, training history), conditions (during a match or training session), the mechanism (collision with an opponent/hit/without an acute crash or impact), type of accident (fracture, dislocation, sprain, strain, contusion, etc.), number of days that the subject missed training or competition due to injury, and date (year) of the accident. Stork Test was used to measure static balance, and Star Excursion Balance Test was used to measure dynamic balance [18]. Descriptive statistics (Mean±SD) and inferential statistics (Shapiro-Wilk test and independent t-test) were used to analyze the results.

Results
The results showed that the subjects had experienced lower limb injuries (especially ankle and knee injuries) more than other injuries. Knee injuries accounted for 41%, and ankle injuries accounted for 36% of all injuries. 25.5% of these injuries were aspirin, 24.5% were tendonitis, and 11% were patellofemoral pain syndrome. Also, 68% of the subjects had experienced an ankle injury once, 22% of the subjects twice, and 10% of the subjects had experienced an ankle injury three times in the last two years, of which 41.7% had suffered injuries during the competition, and 58.3% of injuries occurred during exercise. Table 1 presents the Mean±SD of static and dynamic balance with the minimum and maximum records of the students participating in this study in the two groups of "injured" and "control" in different situations.
The independent t-test results confirmed a significant difference between the school basketball players' static balance and the control group (P=0.001). Still, no significant difference was found between the school basketball players' dynamic balance with an ankle injury and the control group (P=0.887).

Discussion and Conclusion
Based on the research results, it can be concluded that there was a significant difference between the static balance of the school basketball players and the control group. Still, no significant difference was found between the school basketball players' dynamic balance with ankle injuries and the control group. In general, it could be concluded that one of the causes of ankle injuries in school basketball players during landing might be their abnormal foot posture. Therefore, sports coaches and teachers should consider the necessary measures to correct these anomalies using special medical shoes and insoles, and shock absorbers. Athletes with a history of ankle injuries have some degree of functional impairment due to the severity of the initial injury, the treatment, and the quality of the rehabilitation program, which can interfere with their athletic performance. Finally, it should be noted that due to the type of this research (post-event) and purposive selection of the subjects, the results should not be generalized to the entire student sports community.

Compliance with ethical guidelines
All ethical principles were considered in this article. The participants were informed about the purpose of the research and its implementation stages; they were also assured about the confidentiality of their information; Moreover, They were allowed to leave the study whenever they wish, and if desired, the results of the research would be available to them.

Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-forprofit sectors.

Conflicts of interest
The authors declared no conflict of interest.