1.    Introduction
Power, speed, and timing are some of the most important factors for striking skills in martial arts (5). The relationship between speed and accuracy of movement in performing targeted tasks is one of the strongest phenomena of human motor performance, which has been proven by numerous studies (11, 12). Speed and accuracy are applicable to everyday actions as well as fine and gross motor skills (13).
There are few studies on the factors affecting speed and accuracy of movements and their relationship with motor skills. Studies have shown that speed and accuracy of movements are influenced by biofeedback training (14), fatigue (15), task difficulty and handedness (16), attention and focus (17), and feedback presentation (18). Based on previous research, this study assumes that there is a direct relationship between balance and performance in executing direct leg strikes in wushu. Furthermore, this relationship will be strengthened by reducing the width of the target. Given the importance of maintaining balance in executing leg strikes in martial arts and the need to pay attention to speed and accuracy in performing sports skills, the aim of this study is to examine the relationship between static balance and the speed and accuracy of individual performance during a direct leg strike in wushu.
2.    Methods
This study adopted a descriptive-correlational design. A sample of 25 wushu athletes was selected using convenience sampling. The criteria for entering this study were age range of 15 to 20 years and a minimum of 3 years of continuous activity in this sport. Individuals who had suffered upper or lower limb injuries or surgeries in the past year were excluded from the study.
Static balance was measured using the BESS test. This test consists of three standing postures: double-leg stance, single-leg stance on the non-dominant foot, and tandem stance, on both stable (ground) and unstable (foam balance pad) surfaces. In this test, each individual stood barefoot with their eyes closed and their hands on their hips for 20 seconds. The average number of errors in two trial was recorded for each individual (21). Semi-dynamic balance was measured using the star excursion balance test.
To measure the accuracy and speed of direct leg strikes, a 180 cm boxing bag was used. The target area for the leg strike was marked with two colored tapes. To calculate the accuracy of strikes, the test was performed once with two wide targets (8 by 25 cm colored stripes) and once with two narrow targets (2 by 25 cm colored stripes) placed 100 cm apart. The number of correct strikes within 20 seconds was counted as the accuracy score, and the speed of strikes was determined by dividing the number of correct strikes by the execution time.
After checking the normality of the data using the Shapiro-Wilk test, the statistical analysis of variance was used to compare different balance conditions in the BESS test, and the dependent t-test was used to compare the effect of target width on leg strike accuracy and speed. Pearson correlation was used to examine the relationship between balance test scores and accuracy and speed scores. The data were analyzed using SPSS software with a significance level of p<0.05.
3.    Results
Factor analysis in the BSE test showed that stability factor (p=0.001, F=5.90) and base of support (p=0.000, F=18.9) have a significant effect on standing time. Pairwise comparisons showed that the least error occurred in the stable base condition of standing on both feet, while most errors occurred in the unstable surface condition of standing on one foot. Results also showed that the number and speed of kicks were significantly higher in conditions with wider targets compared to those in narrow targets. The correlation test results indicated a generally weak to moderate negative relationship between static balance and direct foot speed, as well as a negative relationship between accuracy of kicks and static balance. However, none of these relationships were significant. The star test reported an average and positive correlation.
4.    Conclusion
The aim of this study was to investigate the relationship between static and semi-dynamic balance with accuracy and speed of direct foot kicks in Wushu. The results showed that the number of errors increased when the individual was placed on an unstable foam surface compared to a stable surface. Standing on an unstable surface results in less sensory receptors in the foot and therefore less information is transmitted, which is one of the reasons for reduced balance, especially when standing on one foot. The correlation test results between static balance with speed and accuracy of foot kicks showed a weak to moderate and non-significant relationship between them. The highest correlation was observed between kick speed in the wide base of support condition, and the obtained coefficient suggests that improving static balance may increase foot speed by about 4% and kick accuracy by 12% in Wushu athletes. Similar weak relationships were observed in the studies of Trasi et al. (2012) and Herrington et al. (2006) between static balance and execution of Australian football movements. This finding shows that the requirements for maintaining balance, especially when standing on one foot, are different from those needed to support the body during kicking movements. Additionally, a weak correlation was observed between kick speed and semi-dynamic balance, but a moderate relationship was observed between kick accuracy and semi-dynamic balance.

Ethical Considerations
Compliance with ethical guidelines
There were no ethical considerations to be considered in this research.
Funding
This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors.
Authors' contributions
All authors equally contributed to preparing article.
Conflicts of interest
The authors declared no conflict of interest.